Papers for

urban planning teams

Papers whose findings have a practical use for this group, as judged from the abstract. Open a paper to read what it means in practice.

Edge system predicts cyclist safety scores from handlebar cameras

Edge-Assisted Crowdsensing for Explainable Cyclist Safety Perception

Abstract: Cyclist fatality rates remain high despite policy support for active travel, and autonomous vehicles add complexity to mixed traffic. Neither crash statistics nor multi-model detection pipelines scale to continuous monitoring of perceived safety along a route. We present an edge-assisted crowdsensing system: handlebar cameras supply street-level frames, a vision-language model (VLM) turns each frame into structured traffic attributes through a single prompt, and an explainable boosting machine (EBM) combines them with OpenStreetMap road infrastructure and on-bike kinematics to predict a crowdsourced 1-9 safety score. Extraction belongs at the network edge: the fastest self-hosted model needs 2.49 s per frame and scoring takes 0.4 ms on a CPU. On 1,362 annotated frames from two London routes, the EBM regressor reaches 72.2 percent binary accuracy and a mean absolute error of 1.011 under five-fold cross-validation. It is within one accuracy point of black-box ensembles. Its per-feature shape functions give exact attribution: physical lane separation is worth +0.97 rating points, a painted lane +0.70 and a construction site -0.65. Planners can therefore price an infrastructure change in rating points, and the results enter cost-benefit analysis directly. We also report inter-annotator agreement (alpha = 0.4695), an attribute audit, and a sensitivity analysis linking attribute error to accuracy. With re-encoding, a 20 s sampling interval serves 1,000 riders at 54 Mbit/s at a cost of 1.4 accuracy points, making continuous monitoring practical.

Thu 5 NovComputer Vision and Pattern Recognition
The gist
Cycling can be dangerous, and it’s hard to continuously monitor how safe cyclists feel on their routes. The authors made a system that uses cameras mounted on bike handlebars to capture street views, and a special AI model to understand what’s in each picture. By combining this information with map data and bike movement, their system estimates how safe cyclists feel along the way. This helps city planners see which road features make cycling safer or more risky, supporting better decisions for cycling infrastructure.
Open → 2611.08441v1

Terramesh-masks improves earth observation image segmentation with open vocabulary

TerraMesh-Masks: Open-Vocabulary Segmentation for Earth Observation

Abstract: Open-vocabulary segmentation (OVS) enables models to segment a variety of concepts specified in natural language, removing the need for fixed label sets and fine-tuning. While recent OVS approaches have shown strong performance on natural images, they transfer poorly to Earth observation (EO) data due to differing semantics, scales, sensing modality, and geographic context. To date, large-scale EO-specific datasets and benchmarks for OVS remain scarce. We, therefore, introduce TerraMesh-Masks, a large-scale open-vocabulary segmentation dataset for EO, comprising 16 million binary masks aligned with nine million multimodal TerraMesh samples and annotated using OpenStreetMap and Overture-derived semantics. In addition, we provide an expert-reviewed evaluation set of 523 samples covering over 200 classes to enable robust evaluation. To demonstrate the impact of TerraMesh-Masks, we build an open-vocabulary version of TerraMind. Our results demonstrate significantly improved performance over general-purpose state-of-the-art models reaching 35.18% IoU versus 16.29% for DINOv3.txt and 11.33% for SAM-3. We release the dataset publicly under a permissive license at https://huggingface.co/datasets/ibm-esa-geospatial/TerraMesh-Masks.

Thu 5 NovComputer Vision and Pattern Recognition
The gist
Segmenting Earth observation images into meaningful parts is hard because such images differ a lot from regular photos. The authors created TerraMesh-Masks, a huge dataset with millions of annotated segments for satellite images that link to real-world map data. They tested a segmentation tool on this dataset and got much better results than popular existing models. This work helps computers understand and identify many types of land and structures in satellite images without needing retraining.
Open → 2611.08081v1

ChangeJEPA improves remote sensing change detection accuracy by predicting states

ChangeJEPA: Predict Before You Compare for Remote Sensing Change Detection

Abstract: Remote sensing change detection is typically formulated as Siamese feature comparison, where two images are encoded independently and a decoder determines which discrepancies correspond to meaningful change. This is challenging because the encoders preserve both true scene changes and nuisance variations such as illumination, seasonal, radiometric, and geometric differences. We introduce ChangeJEPA, a bitemporal joint-embedding predictive architecture that reformulates change detection as latent post-state prediction. Given a pre-change image and partial post-change evidence, ChangeJEPA predicts the full post-change representation under two complementary conditions: a prior hypothesis derived from the pre-change scene and an updated hypothesis conditioned on observed post-change context. A joint-embedding predictive loss aligns both hypotheses with the target latent representation, encouraging semantic consistency while suppressing transient appearance variations. Change is then inferred from the disagreement among the pre-change representation, the observed post-change target, and the predicted latent states, capturing complementary evidence of change, prior surprise, contextual update, and prediction reliability. Across SYSU-CD, LEVIR-CD+, and CDD, ChangeJEPA consistently outperforms its decoder matched Siamese baseline by up to 1.51 IoU points and achieves the best IoU and F1-score on all three benchmarks, demonstrating the advantage of latent post-state prediction over direct feature comparison. Page: https://buddhi19.github.io/ChangeJEPA

Tue 3 NovComputer Vision and Pattern Recognition
The gist
Detecting changes in satellite or aerial images is tricky because differences can come from lighting, seasons, or camera angles, not just real changes on the ground. The authors designed ChangeJEPA, a method that predicts how the scene should look after a change using both the old image and part of the new image. By focusing on predicting the underlying scene instead of just comparing images directly, ChangeJEPA better tells apart real changes from irrelevant variations. Tests on multiple datasets showed that it improves accuracy compared to older methods.
Open → 2611.05570v1

RingMatch improves wide-area cross-view camera localization accuracy

Beyond Local Refinement: Wide-Area Precise Cross-View Localization

Abstract: Fine-grained cross-view localization aims to precisely localize a ground camera against geo-referenced aerial imagery, but current methods typically assume a narrow geographic prior, substantially limiting their applicability when upstream localization remains coarse. To bridge this gap, we study this task over much larger aerial regions. However, this seemingly simple extension fundamentally changes the localization problem: the growing disparity in spatial extent between ground and aerial views makes reliable cross-view matching difficult to establish directly, while the increasing number of look-alike locations in larger regions introduces substantial visual ambiguity. To address these challenges, we propose RingMatch, a search-and-verification framework for wide-area cross-view localization. RingMatch first leverages predictive uncertainty to uncover plausible locations and progressively zooms into their surroundings to obtain increasingly fine-grained evidence, yielding a compact set of promising candidates. We then introduce the depth ring, a novel geometric representation that reveals subtle variations in the spatial layout around a location and serves as a view-shared spatial signature for an LVLM verifier to resolve residual ambiguity. To benchmark this setting, we construct VIGOR-Pro by composing VIGOR aerial tiles into contiguous regions with spatial extents of up to 400 m. Experiments show that RingMatch maintains strong localization performance as the aerial region expands, consistently outperforming representative end-to-end and retrieval-based methods.

Tue 3 NovComputer Vision and Pattern Recognition
The gist
Finding the exact location of a camera on the ground using aerial images is tough when looking at large areas because many places look alike from above and the views are very different. The authors created a method called RingMatch that narrows down possible locations step-by-step and uses a special ring-shaped map of the area’s depth to tell subtle differences between places. They also made a new dataset to test this method on bigger areas compared to before. Their approach works better than previous methods, even as the area gets much larger.
Open → 2611.04759v1

Robust online hd maps fuse satellite and camera inputs

ReSMap: Recasting Satellite Priors for Robust and Accurate Online HD Map Construction

Abstract: Despite recent advances in camera-based online HD map construction, these systems remain susceptible to sensor failures due to their reliance on onboard cameras. In contrast, satellite images remain available independently of real-time sensing conditions as they are cached offline. Existing methods utilizing satellite images, however, primarily leverage them under nominal conditions, without explicitly addressing them as redundancy when a sensor degrades. To address this gap, we propose ReSMap, a redundancy-aware camera-satellite fusion framework for robust online HD map construction. Our framework explicitly leverages satellite images as a complementary source to improve robustness against camera failures. A Predict-then-Fuse (PTF) module fuses camera and satellite BEV features by using each branch's own prediction confidence as a per-pixel reliability weight, with no learned router. An Object-Centric Cooperative Multi-modal Query (OCMQ) decoder then extends this per-modality separation to the query level: each modality cross-attends only to its own BEV, and per-modality updates are merged through a learned per-token gate. Our model achieves state-of-the-art performance on nuScenes across all splits and range settings. More importantly, it also sets the new state-of-the-art under camera-failure scenarios, demonstrating that satellite images serve not only as a strong prior but as practical redundancy for robust online HD mapping.

Tue 3 NovComputer Vision and Pattern RecognitionRobotics
The gist
Building detailed maps online using cameras on vehicles can fail if those cameras stop working well. The authors propose a new method called ReSMap that combines information from onboard cameras and offline satellite images. Their system uses smart ways to weigh and merge data from both sources, improving map accuracy and robustness. It works well even when cameras fail, using satellites as backup information. This method performs better than previous approaches on a popular autonomous driving dataset.
Open → 2611.04352v1

Human mobility gaps filled by memory based power law decay method

Inferring missing locations in human mobility data using memory effects

Abstract: Empirical datasets used to characterize human mobility are sparse in space and time, owing to technological factors such as coverage and battery, or to the erratic nature of online interactions. Missing data can bias the conclusions drawn from them, so filling the gaps in incomplete timelines is a key challenge in computational social science. Here, we propose a simple imputation method in which the informativeness of an observation decays with its bidirectional temporal distance from the missing entry, at a rate set by a single parameter per individual. On synthetic and real Twitter data, a power-law decay, selected by Bayesian model comparison, yields accurate imputations (macro-AUROC above 0.9 overall, and above 0.8 for the most mobile users) and matches a gap-aware continuous-time Markov chain, outperforming it among the most mobile users. The method is robust to moderate noise and generalizes across countries and European administrative regions.

Sat 31 OctMachine Learning
The gist
Data about where people move is often incomplete because of technology limits or unpredictable online activity. The authors created a simple way to guess missing locations by assuming recent and nearby times are more informative, using a memory effect that fades with time. Their method works well on both fake and real Twitter data, especially for people who move a lot. It also performs better for some users than previous approaches and works in different countries and regions.
Open → 2611.01319v1

Quantum inspired networks improve high resolution land cover maps

Quantum-Inspired Convolutional Networks for High-Resolution Pseudo-Label Generation from Multimodal Earth Observation Data

Abstract: Accurate land-cover mapping from multimodal Earth observation (EO) data remains a challenge in regions where high-resolution annotations are scarce or costly to obtain. This work introduces a quantum convolutional encoder-decoder network for pseudo-label generation using Sentinel-1 SAR and Sentinel-2 multispectral imagery, guided only by coarse MODIS-derived land-cover maps. The proposed framework uses quantum-inspired convolutional blocks to enhance feature extraction and cross-sensor fusion, enabling the model to infer a fine-scale semantic structure from heterogeneous inputs. Experiments were conducted on the DFC2020 dataset, which provides a quadruple of Sentinel-1 SAR, Sentinel-2 multispectral, low-resolution MODIS labels and high-resolution reference land-cover maps. The proposed training framework first learns a robust representation of multimodal inputs through the reconstruction branch before any supervision from low-resolution labels is applied. This self-supervised stage enables the model to capture a fine-scale spectral-spatial structure, which is then used to generate high-resolution pseudo-labels. These pseudo-labels are subsequently evaluated through classification metrics on the test data, demonstrating that the proposed approach produces more spatially coherent and class-consistent compared to classical baselines. The results highlight the potential of quantum-inspired deep learning to improve label generation in low-annotation remote sensing scenarios, offering a scalable path towards high-quality land-cover products for EO applications.

Thu 29 OctMachine LearningComputer Vision and Pattern Recognition
The gist
Getting detailed maps of land types from satellite images is hard when detailed labels are missing. The authors created a special kind of computer network inspired by quantum computing ideas that combines different kinds of satellite data to guess detailed land cover maps from rough, low-resolution ones. Their method first learns about the input images on its own, then uses rough maps to create more accurate, detailed label maps. Tests showed their approach makes clearer, more consistent land maps than older methods.
Open → 2610.39773v1

ArchiveLens extracts detailed building data from historical urban maps

ArchiveLens: A Generative Spatial Knowledge Framework for Semantic Reconstruction of Historical Maps

Abstract: Historical maps contain dense morphological and semantic information about past urban environments, but many digitization workflows focus primarily on extracting geometry, and do not capture cartographic semantics such as building use and construction materials. This study introduces ArchiveLens, a generative spatial knowledge framework that operationalizes historical maps as entity-centric, machine-queryable geospatial databases. The pipeline decouples morphological and semantic reconstruction through three stages: tiled YOLOv11-seg instance segmentation for building footprint extraction; deterministic material classification via hue, saturation, and value (HSV)-based color thresholds; and localized attribute parsing using a quantized vision-language model constrained by domain-specific prompts. Extracted entities are integrated into a hybrid Spatial-Temporal Retrieval-Augmented Generation (ST-RAG) architecture that combines dense semantic retrieval with symbolic spatio-temporal filtering and mandatory provenance grounding. Applied to 445 georeferenced Sanborn map sheets of Chicago (1918-1950), the framework achieves high geometric and semantic accuracy. Beyond performance, ArchiveLens advances GIScience by formalizing historical cartography as structured spatial knowledge representation, allowing researchers to query building attributes and compare spatial patterns across map sheets and years.

Mon 26 OctArtificial IntelligenceComputers and SocietyMachine Learning
The gist
Historical maps show lots of details about old cities but often only their shapes get digitized. The authors created ArchiveLens, a computer system that not only finds building outlines but also reads their materials and uses by combining image analysis and language understanding. This system turns old maps into digital databases where you can search and compare building features over time. They tested it on 445 pages of Chicago maps from 1918 to 1950 and got accurate results. This helps people study how cities changed using detailed map information.
Open → 2610.35606v1

OlmoEarth v1.3 creates compact remote sensing data vectors efficiently

OlmoEarth v1.3: Embeddings

Abstract: We make some OlmoEarth embeddings. To do this, we train a new model: OlmoEarth v1.3. OlmoEarth v1.3 is designed to condense multimodal, multitemporal remote sensing data into a single digestible 64 or 128-dimensional vector. OlmoEarth v1.3 produces state-of-the-art embeddings. In addition, OlmoEarth v1.3 is a strong encoder backbone -- competitive with OlmoEarth v1 and v1.2 -- while requiring 18% and 53% of the GPU hours to train, respectively. We use OlmoEarth v1.3 to compute global, annualized 10m embeddings, which we release under the OlmoEarth artifact license.

Fri 23 OctComputer Vision and Pattern Recognition
The gist
Satellites produce a lot of data about Earth over time, but it is hard to use because it's large and complex. The authors created OlmoEarth v1.3, a system that squeezes this data into small, easy-to-use summaries called embeddings. These embeddings keep important information from images and time changes while being faster and cheaper to make. The new model matches or beats older versions while using much less computer power. They also share global yearly summaries made from satellite images at a fine scale to help others use this data.
Open → 2610.32294v1

GeoAI framework ranks urban basins to screen flood risk with human feedback

A Topology-Guided GeoAI Agentic Framework for Urban Flood Screening

Abstract: Open-world geographic artificial intelligence (GeoAI) agents can transform public geospatial data into accessible decision support for real-world challenges, but must balance autonomous reasoning with reliable spatial analysis and human oversight. We present a topology-guided GeoAI agentic framework for urban flood screening that takes a place name, drawn region, or uploaded boundary and returns ranked candidate basins with an interactive map and report. A deterministic controller retrieves public elevation, rainfall, soil, land-cover, exposure, and infrastructure layers, extracts terrain depressions with discrete Morse theory, and ranks basins with a relative flood-priority score. The language model acts only at recorded decision points: selecting a persistence threshold from a precomputed candidate table, drafting recommendations from computed evidence, and reviewing each recommendation against the same evidence. Three human-in-the-loop checkpoints let users revise the threshold, factor weights, or recommendation. In a College Park, Maryland case study, the selected threshold reduced 278 raw terrain minima to 70 basins, with 77% of these basins' lowest points also identified as sinks by a separately computed eight-direction (D8) flow-routing model. Across four further study areas, agreement ranged from 61% to 83%. By combining open data, explicit spatial reasoning, traceable evidence, and human oversight, the framework enables transparent first-pass flood screening while keeping consequential recommendations inspectable and user-controlled.

Thu 22 OctArtificial Intelligence
The gist
Flooding in cities can be hard to predict because it depends on lots of natural and human factors. The authors created a computer system that uses maps and public data to find low-lying areas where water might collect, scoring them to show which are most at risk of flooding. The system uses a step-by-step logic and lets people check and adjust its choices to make sure results are clear and trustworthy. They tested it in Maryland and other places, finding good agreement with existing flood models while keeping humans in control.
Open → 2610.30660v1

OpenEarth-OVS44 dataset boosts remote sensing land-cover segmentation

OpenEarth-OVS44: A Multimodal Remote Sensing Dataset for Open-Vocabulary Segmentation

Abstract: In remote sensing, open-vocabulary segmentation is particularly important for flexible and scalable land-cover understanding across diverse regions, as it improves generalization to novel categories without requiring exhaustive pixel-level annotations. Despite its great promise, progress in this area remains largely constrained by existing datasets with limited category coverage and overly coarse taxonomies, and therefore struggles to support fine-grained semantic understanding required in real-world applications such as urban functional zoning, carbon accounting, and post-disaster assessment. To address these challenges, we present OpenEarth-OVS44, a multimodal benchmark with 290,587 expert-verified segments from 2,832 RGB images and 1,341 strictly registered RGB-SAR pairs at sub-meter spatial resolution, covering 40 cities across France, Japan, and the United States under a unified 44-class taxonomy organized into 9 base categories. Three evaluation tracks are provided: an RGB-only fine-grained benchmark, a multimodal track with diverse synthetic cloudy conditions for weather-robust evaluation, and a held-out cross-region track. Extensive experiments on representative open-vocabulary segmentation models demonstrate that training on OpenEarth-OVS44 substantially improves fine-grained segmentation performance over the strongest training-free baseline, with improvements of up to 7.1 mIoU points on unseen categories and 27.6 mIoU points on seen categories. The dataset and code will be released.

Wed 21 OctComputer Vision and Pattern Recognition
The gist
Understanding land cover from satellite images is hard because there are many types of surfaces and things to recognize, and it takes a lot of work to label them all. The authors created a large and detailed dataset called OpenEarth-OVS44 with many expert-labeled images from different countries. This dataset helps computer programs recognize land types even when they haven’t seen them before and under different conditions like weather changes. Their tests show that training on this data improves how well these programs can identify specific land covers.
Open → 2610.29642v1

Foehn model forecasts air pollution more precisely days ahead

Global probabilistic forecasting of air pollution

Abstract: Fine particulate matter (PM2.5) refers to particulate matter with an aerodynamic diameter of 2.5 micrometre or less. It comes from human activities, such as traffic and industry, and from wildfires, desert dust and gases emitted by vegetation. Short-term exposure to it accounts for about a million deaths a year. Operational forecasts run on grids tens of kilometres wide, which hide the pollution breathed by nearly two hundred million people a day. Machine learning has transformed weather forecasting, but data-driven forecasts of air pollution still blur extremes and lose skill as the air travels. Here we introduce Foehn, a generative model that learns from global kilometre-scale estimates of PM2.5 and computes where the air comes from. Over a year of retrospective forecasts, it outperforms the operational forecast at three stations in four and forecasts at the scale of this hidden exposure. Its ensembles are calibrated, and their mean detects local pollution extremes four days ahead as well as the operational forecast does one day ahead. Such forecasts could warn the millions whom coarse maps miss, once kilometre-scale data are available in real time.

Mon 19 OctArtificial Intelligence
The gist
Air pollution from fine particles harms many people every year, but current forecasts are often too coarse for local details. The authors present Foehn, a model that predicts tiny particle pollution with much finer detail and up to four days ahead. It learns from global data and tracks where the polluted air comes from, improving forecast accuracy and alerting people to pollution spikes missed by other systems. This could help warn communities at high risk from local pollution well before it happens.
Open → 2610.25941v1

X-Fly improves aerial drone navigation with smarter chunked actions

X-Fly: Learning to Reach and Stop in Full-Chunk Aerial Vision-Language Navigation

Abstract: Aerial vision-language navigation (VLN) agents built on large vision-language models are expensive to query. Executing a complete predicted action chunk before replanning amortizes this cost, reducing model inference from 195 to 42 ms per executed waypoint for our policy. It also moves the states at which the policy is queried away from expert demonstrations, which supervise neither recovery from these states nor termination at the learner's own arrival. On OpenFly test-seen, no-stop failures account for 47.78% of full-chunk behavior cloning (BC) outcomes. We present X-Fly, a staged training framework for full-chunk aerial VLN. Recovery DAgger labels learner-visited decision states with smooth chunks that reconnect to future expert segments and with STOP at the first in-region state. Flow-GRPO then jointly refines the chunked flow controller and a Bernoulli STOP policy from same-task closed-loop outcomes, supplemented by outcome-verified stopping supervision. With eight controls per decision, X-Fly reaches 74.18% SR on test-seen and 51.73% on test-unseen, compared with 16.45% and 18.43% for full-chunk BC and 32.04% and 29.46% for DreamFly.

Thu 15 OctRoboticsArtificial IntelligenceComputer Vision and Pattern Recognition
The gist
Navigation for aerial drones using large vision-language models is slow because these models take time to process each waypoint. The authors found that grouping waypoints into chunks speeds things up but causes problems when the drone doesn't know when to stop or how to recover from unexpected states. They developed X-Fly, a two-step training method that teaches drones to safely follow chunked instructions and decide when to stop. This approach almost doubles success rates in familiar and new environments compared to earlier methods.
Open → 2610.21450v1

Forecasting system adapts to changing times places and data gaps

VaryST: Generalizable Spatio-Temporal Forecasting Beyond the Closed-World Setting

Abstract: Spatio-temporal forecasting is fundamental to many real-world systems, yet deployment environments are inherently varying: temporal distributions may evolve, spatial domains may change, and observation availability may shift from training conditions. Existing models are often tightly coupled to their training environments through node-specific representations, predefined spatial support sets, and reliance on consistently available observations, limiting generalization to changing environments. To this end, we propose VaryST, a compact spatio-temporal forecasting model trained from scratch that achieves strong generalization by dynamically constructing predictive context from available long-term observations. To accommodate temporal changes, VaryST derives node representations from long-term histories, capturing current behavior in the context of longer-term patterns. To adapt to spatial changes, it dynamically selects functionally relevant support nodes beyond predefined neighborhoods and integrates their information with recent and long-term target states and global context. To handle varying observation availability, VaryST selectively masks historical patches on which the model relies most during training, encouraging it to exploit alternative temporal and spatial dependencies for accurate forecasting when key observations become unavailable. Extensive experiments on six real-world datasets against seventeen baselines show that VaryST achieves strong in-domain forecasting accuracy, substantially improves zero- and few-shot generalization under spatial and temporal changes, and remains robust to varying observation availability.

Wed 14 OctMachine LearningArtificial Intelligence
The gist
Spatio-temporal forecasting means predicting how things change over time and space, like weather or traffic. Many existing forecasting models only work well in the exact conditions they were trained on and struggle when the environment or available data changes. The authors propose VaryST, a model that learns from long-term historical data and dynamically adapts to new places, changing patterns, and missing observations. VaryST performs well even when tested on new situations it hasn't seen before, making it more flexible for real-world use.
Open → 2610.19813v1

Geospatial vector geometry improves spatial reasoning in vision language models

Geospatial Vector Geometry as a Native Spatial Modality for Vision-Language Models

Abstract: Geospatial reasoning links VLMs to real-world action and decision making. Reliable reasoning requires accurate spatial information and effective spatial representations. However, current VLMs obtain this information mainly from language and vision. At larger geographic scales, limited visual observations make it difficult to establish accurate spatial references and recover precise spatial relations. This leads to a bottleneck for VLM spatial perception and reasoning. This paper proposes that geospatial vector geometry can become a native spatial modality within a VLM and introduces GeoVec-VLM. First, we develop a structured geometry representation that preserves the spatial structure and arrangement of vector objects, building an explicit spatial basis. Second, we introduce a geometry interaction strategy that brings this basis into multimodal computation, where it interacts with visual content and language references according to the queried spatial relations. Together, these designs allow perception and reasoning to operate on shared geometric references. Across five spatial reasoning tasks, GeoVec-VLM improves mean accuracy by about 11\% relative to the strongest baseline, maintains its gains under geographic transfer, and shows greater geometric consistency. Our results show that geospatial vector geometry offers a promising internal spatial basis for VLM spatial reasoning. https://github.com/TXFR/GeoVector-VLM

Mon 12 OctArtificial Intelligence
The gist
Understanding and reasoning about space in vision-language models is hard when looking at large geographic areas because they mostly rely on pictures and words. The authors found that using geospatial vector geometry as a built-in way to represent spatial information helps these models understand space better. They created a new model called GeoVec-VLM that uses this approach to connect geometry with images and language, improving accuracy by about 11 percent on spatial tasks. This method also works well when applied to new geographic areas and keeps spatial relationships more consistent.
Open → 2610.16769v1

Semantic guided 3D gaussian splatting improves urban scene reconstruction

3D Gaussian Splatting for Fine-grained Urban Scene Reconstruction via Semantic-guided Density Control and Loss Design

Abstract: 3D Gaussian Splatting (3DGS) has been becoming a promising 3D reconstruction technique because of its advantage of high-fidelity rendering effect with high efficiency. However, it still suffers from coarse density control and semantically blind loss functions when reconstructing the fine-grained structures in complex urban scenes. Thus, this study proposes SG-GS, a semantic-guided 3DGS method for fine-grained structure reconstruction. It takes the semantic segmentation deduced by the Segment Anything Model (SAM) as a constraint and systematically integrates it into both Gaussian density control and loss function design. On the one hand, a semantic-constrained adaptive density control mechanism is constructed, which dynamically allocates gradient thresholds to different semantic regions of the scene and introduces an additional boundary-enhanced densification strategy, so that new Gaussians are directed to structurally critical regions. On the other hand, a multi-feature guided loss function is designed, and fine-grained supervision signals are gradually introduced through a phased progressive training strategy, alleviating the artifacts caused by the lack of semantic constraints in the basic loss. Experiments on three datasets show that the proposed method consistently improves reconstruction accuracy. Compared with the original 3DGS, the PSNR increases by approximately 2.7% to 5.2%, while artifacts on linear structures and boundary blurring are effectively mitigated. The method can serve the fine-grained 3D reconstruction of urban scenes.

Mon 12 OctComputer Vision and Pattern Recognition
The gist
Building detailed 3D models of cities is hard because usual methods don't handle tiny structures well and miss important boundaries. The authors improve a technique called 3D Gaussian Splatting by using AI to identify different parts of a scene and guide the reconstruction process. This helps focus on critical areas like edges and lines, producing clearer and more accurate models of urban environments. Their tests show better quality and fewer errors compared to previous methods.
Open → 2610.16292v1

Object focused method improves satellite image resolution and detail

MOSAIC: Multi-Scale Object-Centric Slot Adaptation with Image-Guided Prototype Conditioning for Remote Sensing Image Super-Resolution

Abstract: Pretrained diffusion Transformers provide powerful generative priors for image restoration, yet adapting them to structure-sensitive tasks remains challenging. Existing methods mainly rely on dense low-resolution features as conditions, which often entangle salient objects with dominant backgrounds and provide limited abstraction for recurring structures across scales and samples. We propose MOSAIC, an object-centric representation learning framework that learns compact structural conditions for generative model adaptation. MOSAIC organizes degraded observations into structural slots that capture complementary object-level and layout-level evidence, integrates them across resolutions, and retrieves recurring priors from a shared prototype memory to complement incomplete image-specific information. The resulting representations are injected into selected layers of a frozen diffusion Transformer through lightweight residual modulation, preserving its pretrained generative prior. We instantiate MOSAIC for remote sensing image super-resolution, where small objects, repetitive structures, and large-scale variation provide a challenging testbed. Experiments on UCMerced, AID, and RSSCN7 show consistent PSNR improvements across $\times 2$ and $\times 4$ settings and favorable LPIPS results at $\times 4$. Qualitative results further demonstrate improved preservation of small objects, structural boundaries, and repetitive spatial patterns.

Fri 9 OctComputer Vision and Pattern Recognition
The gist
Improving blurry satellite images is hard because small objects and repeated patterns can get lost. The authors propose MOSAIC, a new way to break down images into meaningful parts that represent objects and layouts at different sizes. This helps a powerful image-enhancing AI understand and restore details better. When tested on several remote sensing image sets, MOSAIC showed clearer images and better object preservation than previous methods.
Open → 2610.13547v1

Spatial reasoning gap revealed in multimodal AI with GeoSpatialBench

Mind the Spatial Gap: A Benchmark for Geospatial Reasoning and Constrained Spatial Editing

Abstract: Understanding and manipulating spatial relations is fundamental to AI systems that reason about physical environments and construct grounded world models. However, existing evaluations of multimodal large language models (MLLMs) for spatial reasoning rely predominantly on static question-answering (QA) over small-scale or synthetic scenes, rarely probing whether models can modify spatial configurations while satisfying explicit geometric constraints. We introduce GeoSpatialBench, a benchmark designed to evaluate an escalating progression of spatial cognition, ranging from spatial relation understanding and geometric reasoning to constrained spatial editing. Grounded in real-world urban data across six geographically diverse cities, GeoSpatialBench evaluates a comprehensive taxonomy of 28 topological, directional, metric, and ordering relations across structured GeoJSON and map image modalities, with ground-truth references and constraints verified via GIS operations. Our empirical evaluation across frontier MLLMs uncovers a stark spatial gap: structured GeoJSON consistently outperforms map images, with multimodal combinations offering no reliable gain over GeoJSON alone, and while models show reasonable competence on qualitative topological and ordering, performance drops on quantitative metric relations. Crucially, editing performance on ordering relations declines relative to QA, and most failed edits violate at least one specified spatial constraint. These results highlight a gap between passively recognizing spatial relations and actively manipulating geometric configurations. GeoSpatialBench provides an open, rigorous diagnostic testbed to benchmark these spatial limitations, laying essential empirical groundwork for physically grounded world models and embodied spatial AI.

Fri 9 OctArtificial Intelligence
The gist
Many AI systems struggle to fully understand and change spatial relationships in maps and city layouts. The authors created GeoSpatialBench, a test that checks how well AI models handle real-world geographic data and maps with precise rules. They found AI models do better when using structured map data but often fail when asked to rearrange places while following strict rules. This shows that recognizing spatial layouts is easier for AI than actively editing them. Their test helps find and improve AI's weaknesses in understanding and handling spatial information.
Open → 2610.12881v1

Perception test challenge expands to city-scale audio visual reasoning

Perception Test 2026: Challenge Summary and Extension to City-scale Audio-Visual Reasoning

Abstract: Continuing the Perception Test challenge series, we organised the fourth edition as a workshop at the European Conference on Computer Vision (ECCV) 2026 in Malmö, Sweden. This edition focused on spatial intelligence and featured four different tracks: unified multiple-choice videoQA and grounded videoQA from the original Perception Test benchmark, alongside two new tracks based on city-scale walking-tour videos (KilometerAudio and KilometerVision). In this report, we describe the new benchmarks used for the city-scale tracks and summarise the winning solutions across all tracks, including a generalist model that competed across all tracks with satisfactory performance. The winning solutions in the newly added city-scale tracks demonstrated that complex spatial and multimodal reasoning can be solved by expensive agentic pipelines, but remains difficult for multimodal models used standalone.

Thu 8 OctComputer Vision and Pattern RecognitionMachine Learning
The gist
Figuring out how machines understand complex sounds and videos over a big city is hard. The Perception Test 2026 challenge added new tests using videos from city-scale walking tours to explore this. The authors showed that while some expensive, multi-step computer setups can solve these tough spatial and multi-sensory questions, standalone models struggle more. They also introduced a versatile model that worked okay across all types of tests. This helps understand what kinds of computer intelligence handle real-world, large-scale audio and video puzzles best.
Open → 2610.12081v1

Benchmarking ai agents for diagnosing urban problems with multimodal data

DUDA-Bench: Benchmarking LLM Agents on Multimodal Data-Driven Urban Diagnosis

Abstract: Urban diagnosis integrates heterogeneous observations to identify urban problems, localize affected areas, and investigate contributing factors, informing evidence-based urban planning and management. However, its reliance on labor-intensive, case-specific expert workflows limits scalability and reuse, motivating the exploration of agent-based execution. To evaluate this capability, we introduce DUDA-Bench, a hierarchical and interactive benchmark that formalizes data-driven urban diagnosis as a multi-stage agent workflow. It comprises 86 atomic and 22 workflow tasks spanning four analytical stages, grounded in multimodal data from 12 cities covering five urban problem types. Evaluations of seven backbone models and five agent systems reveal a substantial gap between isolated analytical competence and end-to-end diagnosis, with system benefits varying across backbones. Trajectory analysis shows that unresolved evidence gaps propagate across stages, while successful recovery involves revising assumptions and actions using feedback. These findings highlight limitations in coordinating analytical capabilities across stages, particularly adaptive planning, evidence integration, and verification. More broadly, DUDA-Bench provides a framework for translating expert analytical workflows into hierarchical agent tasks and process-aware evaluation, supporting systematic assessment of end-to-end analytical capabilities.

Wed 7 OctArtificial Intelligence
The gist
Urban diagnosis helps find problems in cities by analyzing many types of data to decide what needs fixing and where. The authors created DUDA-Bench, a set of tasks that tests how well AI agents can perform this complex, multi-step analysis using data from 12 cities. They found that while AI models can handle some individual tasks, they struggle to complete the full diagnosis from start to finish, especially when adapting plans or verifying information. This benchmark helps show where AI still needs improvement to support real-world city planning and management.
Open → 2610.09374v1

Digital twin helps create real driving data without extra annotations

Digital Twin-Driven Real2Sim2Real: Simulator-Conditioned Generation via Paired Driving-Scene Reconstruction

Abstract: Camera-based 3D perception for autonomous driving relies heavily on large annotated datasets, and deploying such a system to a new target region typically requires data collection and annotation. Generative augmentation has been proposed to reduce this cost, but existing approaches face a fundamental trade-off: label-conditioned methods consume the very annotations they aim to replace, while simulator-conditioned methods offer free annotations but lack visual grounding to specific real environments. This work investigates the extent to which a digital-twin-driven Real2Sim2Real pipeline (DT-R2S2R) can substitute for target-region real data. By reconstructing recorded driving clips inside a georeferenced digital twin (DT-R2S), we condition a diffusion model on geometrically aligned simulator renderings, establishing a digital twin-grounded Sim2Real model (DT-S2R). As a result, DT-S2R synthesizes photorealistic driving images given low-cost yet georeferenced simulator data across both reconstructed and novel simulator scenes within digital-twin coverage. The efficacy of generated data is verified on diverse 3D detectors. DETR3D, especially, reports 93.18% of mAP obtained by a target-region real-data oracle, without employing target images for detector training. Furthermore, simple co-training with existing out-of-target real data outperforms the oracle. Thus, DT-R2S2R can substantially reduce the cost of manual on-site data collection and annotation in digital twin-available districts, providing a practical foundation for scaling 3D perception.

Tue 6 OctComputer Vision and Pattern Recognition
The gist
Collecting and labeling real driving images for self-driving cars is expensive and slow. The authors show how using a digital twin—a detailed virtual copy of a real area—allows them to create realistic simulated images that can train 3D object detectors without needing new real images. Their method uses special image generation models conditioned on the simulated scenes inside the digital twin, producing photos that closely match actual driving conditions. Tests show these generated images can nearly replace real data for training, reducing time and cost in new locations.
Open → 2610.08339v1

Dual-level balancing improves building extraction from satellite images

RBMatch: Dual-Level Class Rebalancing for Semi-Supervised Building Footprint Extraction

Abstract: Accurate building footprint extraction from high-resolution remote sensing imagery is essential for urban planning, disaster response, and environmental monitoring. However, obtaining dense pixel-level annotations is costly, motivating the use of semi-supervised learning (SSL) to leverage unlabeled imagery. In remote sensing, severe foreground--background imbalance poses a particular challenge for self-training, as it can bias pseudo-label generation and the resulting unsupervised optimization toward the majority background class. We show that addressing this imbalance at only one stage is insufficient: balancing pseudo-label selection alone does not prevent background bias from re-emerging during unsupervised loss optimization, a failure mode we term \emph{imbalance leak}. To address this issue, we propose \textbf{RBMatch}, a dual-level class-rebalancing framework that jointly regulates pseudo-label generation and unsupervised optimization. RBMatch combines a supervised learning pathway with a self-training module comprising three components: adaptive class-specific thresholding (ACT) for balanced pseudo-label selection, confidence-aware class-balanced reweighting (CACBR) for mitigating class bias in the unsupervised loss, and distribution alignment (DAL) for matching the predicted unlabeled-data distribution to the labeled-data prior. Experiments on the WHU, INRIA, and Massachusetts building footprint datasets across labeled ratios of 1%--10% show that RBMatch consistently achieves the best building IoU and F1-score among the evaluated methods. The improvement is most pronounced on the highly imbalanced Massachusetts dataset, where RBMatch improves IoU by 1.37 points over the strongest baseline at a 1% labeling ratio and is the only method to outperform the fully supervised baseline across all twelve dataset--ratio settings.

Tue 6 OctComputer Vision and Pattern Recognition
The gist
Extracting buildings accurately from satellite images is hard because there are way more background pixels than building pixels, which confuses computer methods trying to learn from limited labeled examples. The authors propose a method called RBMatch that tackles this problem by balancing the data in two ways during learning: deciding which unlabeled pixels to trust and how to weigh them during training. Their method works better than other approaches on three standard building extraction datasets, especially when very few labeled examples are available. This means their approach could help create better maps from satellite images with less manual labeling.
Open → 2610.07698v1

Vision transformer ensembles improve street panorama segmentation accuracy

Vision Transformer Ensembles for Panoramic Street Segmentation

Abstract: Semantic segmentation of street panoramas can support detailed descriptions of urban environments, yet small datasets and unequal training costs make model selection difficult. This paper presents the system used for a first place submission to the PalmCity challenge in the leaderboard snapshot dated 5 October 2026. Nine pretrained segmentation systems are compared using approximately equal computation budgets. The candidates include DeepLabV3+, SegFormer, UPerNet, Mask2Former, DINOv3 with a linear decoder, and an Encoder only Mask Transformer using DINOv3. The two leading candidates are trained independently with three random seeds and longer budgets. Equal averaging of class probabilities from the three Encoder only Mask Transformer models, evaluated at three image scales with horizontal reflection, produces 60.95% mean intersection over union and 71.16% mean F1 on the 84 image public validation split. The submitted predictions receive 57.08% mean intersection over union and 67.96% mean F1 on the hidden test leaderboard. Producing all 249 test masks takes 251.49 seconds including model initialization and provenance checks on one NVIDIA RTX 5090. Peak allocated GPU memory is 2.70 GiB. The study reports all eligible models, all inference variants, class level errors, source conditions, and reproducibility checks, providing a documented challenge workflow with existing architectures.

Mon 5 OctComputer Vision and Pattern RecognitionArtificial IntelligenceMachine Learning
The gist
Identifying different parts of street panoramic images helps understand urban scenes better, but it can be hard to pick good computer models. The authors tested nine well-known image segmentation systems with similar computing effort and focused on the best two. By combining results from multiple models and looking at images at different sizes and angles, they achieved better accuracy in recognizing street features. Their approach was tested on public and hidden city images, showing reliable performance and efficiency.
Open → 2610.06063v1

Compact tokens improve building footprint detection from angled images

LoDEOT: Low-Dimensional and Efficient Offset Tokens for Building Footprint Extraction from Off-Nadir Imagery

Abstract: Instance-level roof-to-footprint offset (RFO) prediction is central to extracting building footprints from off-nadir imagery. Query-based pipelines commonly use high-dimensional instance tokens to predict signed two-dimensional RFOs. We investigate whether RFO prediction can instead use a compact offset token. Under local pinhole projection and vertical-extrusion assumptions, the idealized RFO map admits a five-parameter sufficient descriptor comprising intrinsic shape, composite amplitude, and relative geometry. This factorization provides a structural prior for a five-dimensional offset token, whose channels learn task-relevant latent representations through end-to-end training. Based on this design, we propose LoDEOT, which retains high-dimensional instance tokens for detection and segmentation but maps instance-token, concentration-gated roof, and box-mask evidence to a five-dimensional offset token followed by an independent two-dimensional readout. Known denoising-query target indices further align each supervised decoder-layer estimate with the same clean instance RFO, organizing successive predictions as target-aligned recovery under perturbed query conditions. Experiments on five real-world building datasets demonstrate the effectiveness of LoDEOT for building footprint extraction. Experiments on real-world building datasets demonstrate that a five-dimensional offset token can support accurate RFO prediction. On BONAI, LoDEOT achieves the best roof-detection bAP and bAP50 and leads all five offset-corrected footprint metrics among the evaluated end-to-end methods, with FAP50 of 54.58 and mEPE of 5.23 pixels. Its FAP50 exceeds those of the evaluated end-to-end baselines by 7.56-16.85 percentage points.

Mon 5 OctComputer Vision and Pattern Recognition
The gist
Extracting building shapes from images taken at an angle is tricky because the roof and footprint don’t line up perfectly. The authors examine if using a small, five-number description can accurately predict this offset instead of large, complex tokens. They design a new approach, LoDEOT, that uses these compact offset tokens and test it on real-world datasets. The results show LoDEOT outperforms previous methods on roof detection and footprint accuracy.
Open → 2610.05899v1

New method improves traffic model tuning with fewer simulations

FLAT: Smoothing the Rugged Landscape for Learnable, Sample-Efficient Traffic Calibration

Abstract: Calibrating microscopic traffic models for digital twins is an expensive black-box optimization problem: tuning car-following and lane-changing parameters requires a full simulation run, affording only a tight budget per recalibration window. Matching raw trajectories yields a rugged objective that sparse surrogates cannot learn, reducing sequential acquisition to near-random probing. We present FLAT, which couples what to optimize with where to sample next. An eight-dimensional behavioral fingerprint smooths the parameter-error landscape, making the objective learnable from a few dozen samples; annealed lower-confidence-bound (LCB) acquisition then spends each remaining run where it most reduces error. The surrogate, interchangeable among a Gaussian process (GP), random forest (RF), or multi-layer-perceptron (MLP) ensemble, plugs into the same LCB loop. Across six heterogeneous real-world scenes, FLAT-GP achieves the lowest scene-averaged behavioral error, winning 6/6 scenes against SPSA, GA, and CMA-ES and 5/6 against TPE under the matched budget. Some baselines need up to 4.4 times more simulations to match. Ablations show objective choice shifts final behavioral error by 81% on average, removing sequential LCB raises the six-scene mean by 20%, and surrogate choice shifts it by at most 4.2%, confirming gains trace to objective geometry and sequential allocation rather than surrogate capacity.

Sat 3 OctComputational Engineering, Finance, and ScienceMachine Learning
The gist
Calibrating detailed traffic simulations is slow and costly because each test requires running a full simulation. The authors developed FLAT, a way to better understand and smooth the relationship between different driving behavior settings and how well the simulation matches real traffic. This makes it possible to learn from fewer tests and focus simulations where they help most. Their method performs better than established techniques across multiple real traffic scenarios.
Open → 2610.04337v1

Neural networks better recognize urban areas in drone images

Recognition of Urbanized Areas in UAV-Derived Very-High-Resolution Visible-Light Imagery

Abstract: This study compared classifiers that differentiate between urbanized and non-urbanized areas based on unmanned aerial vehicle (UAV)-acquired RGB imagery. The tested solutions in-cluded numerous vegetation indices (VIs) thresholding and neural networks (NNs). The analysis was conducted for two study areas for which surveys were carried out using different UAVs and cameras. The ground sampling distances for the study areas were 10 mm and 15 mm, respectively. Reference classification was performed manually, obtaining approximately 24 million classified pix-els for the first area and approximately 3.8 million for the second. This research study included an analysis of the impact of the season on the threshold values for the tested VIs and the impact of image patch size provided as inputs for the NNs on classification accuracy. The results of the con-ducted research study indicate a higher classification accuracy using NNs (about 96%) compared with the best of the tested VIs, i.e., Excess Blue (about 87%). Due to the highly imbalanced nature of the used datasets (non-urbanized areas constitute approximately 87% of the total datasets), the Mat-thews correlation coefficient was also used to assess the correctness of the classification. The analysis based on statistical measures was supplemented with a qualitative assessment of the classification results, which allowed the identification of the most important sources of differences in classification between VIs thresholding and NNs.

Wed 30 SeptComputer Vision and Pattern Recognition
The gist
Identifying urban areas from drone photos is not always easy because places with buildings and plants can look similar. The authors tested different methods, including simple color-based rules and more complex neural networks, to see which works best. They found that neural networks correctly spot urban areas about 96% of the time, better than the color-based rules that were around 87%. They also showed that things like the time of year and how images are divided affect the accuracy. This helps improve mapping cities using drone images.
Open → 2609.40212v1

Cobicount improves remote sensing object counting without target training

COBICount: Separating Object and Background Responses for Remote Sensing Object Counting Without Training on Target Data

Abstract: Remote sensing object counting estimates how many buildings, vehicles, or ships appear in overhead images. Most supervised counters predict a density map, whose sum gives the object count, and assume similar categories, sizes, and backgrounds. Applying them across regions, sensors, or categories often requires target data or further training, which may be costly or unavailable. We study source-only counting. Training for the counting task and model selection use one group of images that shares an object category and similar imaging conditions, with one point marking each object. Target images and information remain unavailable until the model is fixed. This reduces data preparation but makes transfer harder. A model trained on one source may place high density values, called responses, on real objects and repeated background structures. Road edges, parking grids, roof boundaries, and water boundaries may then be counted as objects, creating candidate origin ambiguity. COBICount separates response generation, acceptance, and background suppression. Candidate Evidence (CE) generates possible responses. Candidate Acceptance (CA) keeps compact responses centered on objects. Bias Isolation (BI) reduces responses associated with repeated background structures. Their outputs form the final density map. Trained on RSOC Building and evaluated directly on DOTA Large Vehicle, Small Vehicle, and Ship, COBICount achieves the lowest mean absolute error (MAE) averaged over the target domains among the compared methods, 174.132. It uses 5.07 million parameters and 17.41 billion floating point operations for a 512x512 input. COBICount improves transfer without target data or training for each target. The code will be available at: https://github.com/yixuxi22/COBICount.

Wed 30 SeptComputer Vision and Pattern Recognition
The gist
Counting objects like buildings or vehicles in overhead images is hard when the images come from different regions or sensors than the ones used for training. The authors show a method called COBICount that learns from one set of pictures and then counts objects in very different images without extra training. It does this by separating the detection of possible objects from background patterns that might confuse the count. This makes the counting more accurate when applied to new and varied images without needing new data.
Open → 2609.39366v1

Aperture improves remote sensing image interpretability without training

Aperture: Training-Free Multiscale Concept Bottlenecks for Remote Sensing

Abstract: While earth observation models have advanced substantially, they still lack interpretability. While concept-bottleneck models provide interpretability and expert interaction, they are either too expensive to train for the remote sensing domain or perform poorly without annotation. We posit that in expert domains like remote sensing, such training-free models require both fine details in both image and concept space. In image space, we propose a multiscale concept bottleneck using greedy quadtree routing to locate small concepts. In concept space, we replace contrastive vision language models with pre-trained MLLMs and present a way to get reliable concept scores from them. We introduce APERTURE that blends concept scores at the global image and native concept-scale level to give state-ofthe-art training-free model performance. To test these models, introduce SiFC, a fine-grained concept-centric dataset across three countries, with human-reviewed class-level concept maps. On SiFC, APERTURE outperforms the best training-free baselines by more than 10 percentage points in macro F1-score, and notably also outperforms supervised concept bottleneck models. Targeted component-removal tests examine whether concept scores respond to changes in visual evidence, while temporal experiments show that descriptor updates improve recognition of technological changes without retraining.

Tue 29 SeptComputer Vision and Pattern Recognition
The gist
Models that look at satellite images often struggle to explain their decisions clearly. The authors created Aperture, a model that does not need training but can identify detailed features in images using a special method to focus on small areas and concepts at different scales. They tested it on a new detailed dataset across three countries and found it performed better than other similar models, even those that require training. This helps experts understand what the model sees and why it makes certain classifications.
Open → 2609.38603v1

Unified method improves building maps from diverse satellite images

UniBuild: Unified Building Mapping From Multi-Source Optical Remote Sensing Imagery With Detail Decoding and Geometry Regularization

Abstract: Building extraction from optical remote sensing (RS) imagery is fundamental to urban mapping, yet existing methods are often dataset-specific and generalize poorly to unseen domains. Their practical use is also limited by insufficient detail recovery and weak geometric regularization, leading to blurred boundaries, irregular shapes, and merged adjacent buildings. To address these issues, we propose UniBuild, a unified building extraction framework for multi-source RGB optical RS imagery. First, a unified multi-dataset training scheme is constructed over heterogeneous RGB optical datasets to learn transferable building representations across sensors and resolutions. Second, a novel detail-preserving HR-DPT decoder is designed to integrate high-level semantic features with high-resolution spatial features, enhancing building detail recovery. Third, geometry-aware regularization is introduced through a structure-tensor-based direction-aware loss for boundary direction consistency and a saddle-aware loss for suppressing false activations in narrow inter-building gaps under low-resolution conditions. We train and evaluate UniBuild on multi-source RGB optical datasets, including 10 public high-resolution datasets and two self-collected low-resolution datasets. Experiments show that UniBuild consistently improves building-region accuracy, boundary sharpness, and adjacent-building separation across diverse datasets. It also generalizes well to unseen domains and supports practical building extraction from RGB optical RS imagery up to 10\,m resolution. The predicted masks can be further converted into GIS-compatible building footprints through simple polygonization. The trained model and inference code are released at https://github.com/zhu-xlab/UniBuild.

Tue 29 SeptComputer Vision and Pattern Recognition
The gist
Mapping buildings from satellite pictures is important but hard because different images vary in quality and size, causing blurry or merged buildings in maps. The authors propose UniBuild, a method that learns from many types of images together to better recognize buildings on new, unseen images. Their method also uses advanced tricks to keep building edges sharp and separate buildings that are close together, even in low-quality images. Tests show UniBuild works well across many datasets and resolutions, making it useful for creating detailed, accurate building maps.
Open → 2609.37031v1

Traffic forecast model predicts turn counts without impossible values

LTV-CTDNet: Compositional Turning Decomposition for Short-Term Turning-Movement Forecasting

Abstract: Short-term turning-movement forecasts can support signal control and corridor operations, but unconstrained neural networks may produce physically impossible negative counts or outputs that are not explicitly tied to an approach-demand total. This study introduces the Linear Temporal-Variable Compositional Turning Decomposition Network (LTV-CTDNet), a forecasting framework designed to combine competitive accuracy with structurally admissible outputs. LTV-CTDNet was evaluated using seven months of 15-minute LiDAR observations from eight monitored corridor locations in Nashville, Tennessee. Its lightweight encoder combines recent turning-movement history, weekly time-slot embeddings, and location embeddings. The Compositional Turning Decomposition framework separately predicts nonnegative approach totals and within-approach turning proportions, then reconstructs movement forecasts from these components. Among the evaluated predefined configurations, LTV-CTDNet achieved a movement-level MAE of 1.8189 and RMSE of 3.8072. Its accuracy gains over the strongest sequence models were modest, but it produced no negative forecasts, while unconstrained learned models generated negative values in approximately 10.6% to 29.2% of raw forecast cells. The framework enforces nonnegative outputs and exact agreement between each model-predicted approach total and the sum of its component movements by construction, providing directly interpretable forecasts without clipping or coherence correction.

Sun 27 SeptMachine Learning
The gist
Predicting how cars turn at intersections helps manage traffic signals better. The authors developed a model called LTV-CTDNet that makes short-term forecasts of turning movements using recent traffic and time information. Their model always predicts realistic, nonnegative counts and keeps totals consistent, unlike some older models that sometimes gave impossible negative numbers. They tested it with data from multiple locations and found it to be accurate and reliable.
Open → 2609.34014v1

Map-conditioned model generates human movement adapting to map edits

Editable Map-Conditioned Trajectory Generation for Human Mobility Simulation

Abstract: Geospatial simulation of infrastructure interventions requires mobility generators that respond directly to edited maps, yet many data-driven generators do not expose the map as an editable condition. We formulate this task as map-conditioned autoregressive generation of human mobility: a road raster conditions a decoder that emits nominal 31.25 m mesh-cell tokens at one-minute intervals. The mesh-local vocabulary supports held-out and locally edited maps without retraining or vocabulary changes. We instantiate a ResNet-50 visual-prefix configuration and a Vision Transformer (ViT) cross-attention configuration, trained from scratch on 87,400 smartphone-derived trajectories from 874 meshes in Ishikawa Prefecture, Japan; 219 meshes are held out. We evaluate map sensitivity by comparing correct-map and within-split shuffled-map generations with held-out real trajectories. On the 110-mesh test split, for the ResNet-50 configuration, correct-map generations are closer than shuffled-map generations on 60% of meshes under Hausdorff-based energy distance (p = 0.021), while DTW is directional but inconclusive (57%, p = 0.074); correlation with real density is 0.38 with the correct map versus 0.01 with shuffled maps. The ViT configuration shows weaker trajectory-level sensitivity and smaller density gains. An illustrative bridge-removal edit changes generated continuations without retraining. Together, these results support the feasibility of editable-map human-mobility simulation.

Sat 26 SeptMachine LearningComputers and Society
The gist
Simulating how people move through cities is useful for planning roads and infrastructure. The researchers created a computer model that can generate realistic human movement paths based on maps, and it can react when those maps are edited, like when a bridge is removed. Their model divides the area into small cells and predicts movement step-by-step while looking at the map’s layout. Tests show the model produces more accurate movement patterns when given the correct map compared to randomized maps, supporting its ability to simulate movement changes without retraining.
Open → 2609.32360v1

Astra agent builds detailed 3D building models without training

AstraLOD3: Zero-shot multimodal agentic reconstruction of LOD3 building models

Abstract: Automated LOD3 building modeling typically relies on purpose-built geometric or learning-based pipelines, limiting flexibility across heterogeneous buildings and input evidence conditions. This study investigates whether Astra, a general-purpose multimodal foundation model, can address these limitations through zero-shot reconstruction of LOD3 building models within an agentic framework under bounded autonomy. AstraLOD3 combines multi-view images, calibrated cameras, and a filtered sparse SfM point cloud with a natural-language reconstruction specification, while the Astra agent dynamically selects and executes computational procedures using Python and Blender. Across 35 runs, including 24 benchmark buildings, AstraLOD3 achieved a mean FRDS of 0.9647 and geometric agreement comparable to that of previous purpose-built methods. Controlled ablations further revealed the effects of reconstruction guidance, evidence modalities, model configuration, and run-to-run variability. The results demonstrate that structured LOD3 reconstruction can be formulated as a constrained agentic process rather than as a fixed pipeline. Future work will investigate adaptive refinement, user-guided correction, task-specific specialization, and damage-aware reconstruction.

Wed 23 SeptComputer Vision and Pattern Recognition
The gist
Creating detailed 3D building models often requires specially designed tools or training for each building type, which can be complicated and less flexible. The authors studied whether a general AI model called Astra can build these detailed models automatically, using images, camera data, and sparse 3D points, guided by natural language instructions. They showed Astra can reconstruct high-quality 3D models nearly as well as specialized methods without prior training on the task. Their approach lets the AI choose and run different procedures dynamically, pointing toward more flexible and adaptable building reconstruction tools in the future.
Open → 2609.28061v1

MIND improves geographic data mapping with adjustable spatial detail

MIND the Gap: A Geographic Implicit Neural Representation with Adjustable Spatial Scale

Abstract: Geographic measurements are often sparse, leaving large areas without labels for the quantities we want to map. Geographic implicit neural representations (INRs) address this by learning smooth, general-purpose embeddings that can be queried at any coordinate. Downstream models combine these embeddings with sparse labels to predict target values at unsampled locations without satellite imagery at inference. However, generalization to distant regions remains largely unexplored, despite its importance for remote sensing applications. We introduce Matryoshka Implicit Neural Distillation (MIND), which distills embeddings from specialist pretrained geospatial models into a single generalist coordinate embedding with adjustable spatial granularity. MIND uses nested supervision at several embedding dimensions, which define a series of contiguous chunks. In our experiments, early chunks capture coarser geographic variation, while later chunks add more fine-grained details. A downstream predictor can retain only leading chunks or be fitted with our Chunked Penalty to downweight later chunks while keeping the full embedding, without retraining the INR. To measure MIND and compare to existing approaches around the world, we introduce CoordBench, a large-scale INR evaluation suite of $52$ datasets and $78$ targets that aims to test both local interpolation and prediction in held-out regions at various spatial scales. MIND and its Chunked Penalty variant achieve the highest aggregate regression and classification scores among tested INRs, and the highest scores overall under regional holdout, setting a new state-of-the-art for geographic INRs.

Mon 21 SeptComputer Vision and Pattern RecognitionMachine Learning
The gist
Geographic data often has big gaps where measurements are missing, making it hard to know conditions there. The authors created MIND, a technique that learns geographic patterns at multiple levels of detail from several expert models combined into one. This helps predict unknown values in new areas more accurately, even far away from the original data. To test this, they built CoordBench, a big set of tests across many regions, showing MIND performs better than existing methods for geographic data prediction.
Open → 2609.25454v1

GPU ray tracing speeds up 3D mesh spatial joins by hundredfold

Pierce: GPU Ray Tracing for Spatial Joins over Complex 3D Data

Abstract: Many emerging applications, from computational biology to digital twins and urban planning, rely heavily on three-dimensional spatial joins over polyhedral meshes. These joins comprise computationally-intensive triangle--triangle intersection tests that pairwise compare the faces of polyhedral meshes. Since each mesh may contain thousands of faces, the resulting cost challenges the responsiveness of spatial data management techniques. Existing techniques follow the filter-and-refine paradigm, accelerating either the filtering step through indexing or the refinement step through progressive mesh compression combined with GPU parallelization of triangle--triangle tests. However, the former neglects the high cost of intra-geometry refinements, whereas the latter lowers this cost but still relies on the same pairwise triangle--triangle tests. In this paper, we introduce Pierce, an approach that reformulates three-dimensional spatial joins over complex polyhedral meshes as ray-tracing operations and leverages the hardware ray-tracing units (RT cores) of modern GPUs to accelerate query execution. Our approach casts rays along the edges of one mesh against a spatial hierarchy built over the other, performing ray--node tests at the internal levels to prune distant geometries and ray--triangle tests at the leaves to identify intersecting meshes, both of which RT cores accelerate in hardware. We evaluated Pierce on real and synthetic data against multiple baselines, demonstrating more than two orders of magnitude speedup on digital pathology data compared to the state-of-the-art approach.

Mon 21 SeptDatabases
The gist
Checking how two 3D shapes touch or overlap can be very slow when the shapes have many tiny flat parts. The authors changed this problem into one of tracing virtual rays to quickly find intersections using special GPU hardware built for ray tracing in graphics. This method speeds up the task by over 100 times on some data. It helps connect or compare complex 3D models faster than before.
Open → 2609.24513v1

Synthetic human mobility data methods compared for urban analysis

Synthetic Human Mobility Data Generation: A Structured Review of Representations, Methods, and Practical Capabilities

Abstract: Human mobility data has become an increasingly important component of urban analytics. Although the range of available mobility data sources has expanded substantially, access remains highly constrained by commercial restrictions, privacy concerns, and institutional barriers. Data protection procedures also often reduce the analytical value of released datasets. Synthetic mobility data has emerged as a promising solution, but existing methods differ substantially in their underlying mechanisms, the information they preserve, the outputs they generate, and the analytical questions they can support. Their comparative strengths and trade-offs remain insufficiently understood for urban analytics. This paper presents a structured review of synthetic human mobility data generation from an urban analytics perspective. We review the literature by methodological family and index it by the mobility outputs each family generates natively and the analytical capabilities those outputs enable. We first provide a taxonomy of synthetic data products, including population and persona representations, activity schedules, trip and tour records, trajectories, and aggregate mobility patterns. We then review the major methodological families, spanning mechanistic models, survey-driven population synthesis, activity- and agent-based simulation, deep generative models, transformer-based mobility language models, and LLM-agentic systems. Building on this synthesis, we introduce a Meaning-Population-Autonomy framework that characterises these methods along three dimensions: behavioural meaning, population grounding and scale, and generation autonomy. We consider these dimensions the principal requirements for downstream urban analytics. Few methods deliver behavioural meaning, population grounding and autonomous generation at once, and fewer still with generation constrained to feasible trajectories.

Fri 18 SeptComputational Engineering, Finance, and Science
The gist
Access to real human mobility data is often limited due to privacy and commercial reasons, which makes studying city movement patterns tricky. The authors review different ways to create fake, or synthetic, mobility data that can still help understand how people move in cities. They organize these methods by what type of movement data they produce and how useful they are for analyzing urban life. They also introduce a framework to compare these methods based on how realistic, large-scale, and automated the data generation is. Their work helps city planners and analysts know which synthetic data methods might suit their needs.
Open → 2609.21413v1

Aurora framework makes air ground co simulation more reliable and verifiable

AURORA: A Natural Language-Driven Agentic Framework for Understanding, Reasoning, and Orchestrating Reliable Air-Ground Co-Simulation

Abstract: Air-ground transportation research increasingly relies on co-simulation, yet constructing scenarios remains labor-intensive and difficult to validate. More importantly, a generated scenario may execute successfully while failing to realize the spatial, temporal, communication, or behavioral relationships requested by the user. This paper presents AURORA, a natural-language-driven agentic framework that treats air-ground scenario generation as a process of compilation with verification. Central to AURORA is the Air-Ground Scenario Graph (AGSG), a typed intermediate representation that explicitly connects agents, aerial missions, events, communication links, success conditions, and their cross-domain dependencies. This shared representation enables simulator-grounded parsing, joint road-airspace grounding, temporal planning, pre-execution feasibility checking, trace-based runtime verification, failure localization, and bounded repair within a unified workflow. We further introduce AURORA-Bench to evaluate not only whether generated scenarios execute, but whether they faithfully realize the requested interactions. Experiments across multiple language models show that structured execution substantially improves reliability, while runtime verification exposes silent failures that completion-based evaluation overlooks. Localized repair further resolves many violations without regenerating the entire scenario. The results show that reliable scenario generation requires verifying realized behavior, not merely executable code, and demonstrate the value of explicit intermediate representations for verifiable and repairable language-driven co-simulation.

Thu 17 SeptRoboticsArtificial Intelligence
The gist
Simulating coordinated air and ground transportation can be really hard and time-consuming, especially when making sure the scenarios follow all the rules and interactions intended. The authors introduce AURORA, a system that turns natural language instructions into detailed simulation plans while checking step-by-step that all conditions are met. This method helps catch hidden errors that might not stop a scenario from running but would break its intended logic. They also created a benchmark to test if simulations truly behave as requested, improving trust and fixing problems without starting over.
Open → 2609.19527v1

Vision-language models struggle to assess sidewalk accessibility from photos

Can VLMs Reliably Assess Sidewalk Accessibility Attributes from Pedestrian-Level Imagery?

Abstract: An important component of urban accessibility, particularly for wheelchair users and people with reduced mobility, is sidewalk compliance with measurable requirements. We test whether effective width, longitudinal slope, cross slope, and pavement condition can be assessed reliably from pedestrian-level imagery using vision-language models (VLMs). We present the first application of sampling-based conformal prediction (CP) for VLM-based accessibility assessment. We evaluate four VLMs on 514 sidewalk images from Seoul, South Korea, with field-measured ground truth. Conformal calibration attains the nominal 90% coverage for all models and attributes, but the calibrated regions differ in informativeness. Effective width yields the most informative estimates, with a mean interval half-width of about 1.0 m for the best model. Since every model overestimates width, asymmetric calibration shortens the intervals by up to 33% at unchanged coverage. Longitudinal slope is marginally informative, cross-slope intervals are too wide to resolve regulatory thresholds, and pavement-condition sets degenerate to all five grades (A-E) for three of the four models. Uncalibrated intervals from raw sampling dispersion cover only 17-47% of field-measured values at a nominal 90% level. Among the images with the most self-consistent responses, these intervals miss the field-measured value in up to 96% of cases. Response self-consistency is therefore not evidence of accuracy, and sampling dispersion cannot be interpreted as uncertainty until it has been calibrated against field-measured ground truth. No quantitative attribute reaches the precision required for general compliance assessment, but CP identifies from calibration data alone which attributes can support screening of segments far from the thresholds. We release the annotated pedestrian-level images and their corresponding field-measured attribute values.

Tue 15 SeptComputer Vision and Pattern RecognitionComputers and SocietyMachine Learning
The gist
Making sure sidewalks are safe and accessible for wheelchair users requires measuring things like width, slope, and pavement quality. This paper looks at whether advanced computer models that analyze images and text together can do this from photos taken at street level. The authors found that while these models can guess sidewalk width somewhat well, they often overestimate it and are not reliable for measuring slopes or pavement conditions. Their method also showed that just having consistent answers from the model doesn’t mean the answers are correct. Overall, these models aren’t yet accurate enough to replace real measurements but might help flag really bad sidewalks.
Open → 2609.17882v1

Multimodal AI classifies Emirati homes architectural styles accurately

Multimodal Cultural Heritage Architectural Style Classification for Residential Buildings in the UAE Based on CLIP Embeddings and SVM

Abstract: The analysis and classification of cultural heritage architectural styles remain challenging due to the complexity of visual images of buildings, which are highly relied on in traditional CNN-based classification approaches in comparison to textual descriptions, and the relative lack of non-western region-specific datasets. This paper addresses this gap by proposing a multimodal machine learning framework to analyze and classify Emirati residential architecture using OpenAI's CLIP model. We integrate visual features from images and textual features from expert descriptions into a unified 512-dimensional embedding, followed by dimensionality reduction with UMAP for visualization and unsupervised clustering using K-Means. Cluster labels, which are derived from manual analysis of the K-Means clusters, are used to train an SVM classifier for automated architectural style classification. Our approach achieves a classification accuracy of 98% across eight identified style clusters, higher than every other study in the literature, demonstrating the effectiveness of combining visual and textual modalities. Overall, this paper highlights the potential of using multimodal AI to support architectural heritage analysis, offering scalable and interpretable tools for exploring regional architectural identities.

Tue 15 SeptComputer Vision and Pattern RecognitionArtificial Intelligence
The gist
Classifying architectural styles, especially for cultural heritage buildings, is hard because images alone can be confusing, and there is little data for non-western regions. The authors developed a computer method that looks at both photos of houses and expert-written descriptions together, turning them into a combined data format. They then grouped similar styles and trained a machine to recognize eight different Emirati residential architectural styles with 98% accuracy. This approach shows how combining pictures and text helps machines better understand complex visual categories.
Open → 2609.17181v1

Agentic AI system designed to manage complex geospatial workflows

ANASSA: An Agentic AI Orchestration Framework for Spatial Intelligence

Abstract: The emergence of large language models (LLMs) and large multimodal models (LMMs) has enabled a new class of agentic systems capable of integrating natural language understanding with tool-based execution. In geographic information systems (GIS), this shift is transforming traditional, expert-driven workflows into semiautonomous systems that can interpret user intent, construct spatial workflows, and execute geospatial analysis tasks. However, existing approaches remain limited by fragmented integration of reasoning, execution, and evaluation, particularly in complex, real-world environments. This study synthesizes recent advances in agentic GIS frameworks, benchmarks, and surveys to identify limitations in spatial reasoning, execution robustness, validation, governance, and evaluation. Building on these insights, it introduces ANASSA (Autonomous Neural Agents for Spatial Systems Architecture), an agentic AI orchestration framework that integrates structured spatial reasoning, multi-agent workflow orchestration, execution feedback, authoritative spatial validation, provenance, uncertainty handling, and human decision authority within a unified system design. The contribution is an architecture-level specification: eleven components across four layers, a six-step Geospatial AI Cognitive Loop, cross-component contracts, and governance mechanisms intended to make agentic geospatial workflows traceable, reproducible, and accountable. Empirical performance evaluation is reserved for implementation and deployment studies.

Sun 13 SeptArtificial Intelligence
The gist
Handling complex geographic data analyses usually requires experts to manually plan and execute tasks. The authors point out that current AI tools struggle to fully integrate reasoning, task execution, and validation in this context. They propose ANASSA, a framework that carefully combines these steps to make automated geographic analysis more reliable and traceable. Their work is about how to organize AI components and processes rather than building a specific product or testing performance yet.
Open → 2609.14824v1

Graph neural networks estimate connectivity loss after road disruptions

When does a spectral prior help graph learning? Connectivity-loss estimation under road-network disruptions

Abstract: Rapid evaluation of many simultaneous road-link disruptions requires a practical compromise between exact spectral recomputation and local approximation. We estimate relative algebraic-connectivity loss after multi-edge deletion using graph neural networks (GNNs) that learn a bounded correction to a first-order Fiedler sensitivity. The study considers independent, spatially clustered, and edge-betweenness-targeted failures, with graph-disjoint synthetic splits and zero-shot transfer to 13 OpenStreetMap (OSM) areas in six countries. GCN, GraphSAGE, and edge-aware MPNN backbones are compared with analytical baselines. In expanded OSM tests, residual GCN improves spatial-failure MAE by 0.0391 (95% hierarchical interval 0.0151-0.0662), while residual GraphSAGE improves targeted-failure MAE by 0.0257 (0.0095-0.0446). Second-order perturbation improves first-order MAE by only 0.0028-0.0053. Correction slopes decrease under targeted transfer, indicating residual shrinkage around systematic prior error. Leave-one-country-out OSM-to-OSM transfer is mixed: residual GCN improves targeted-failure MAE by 0.0622 (0.0169-0.1153) but worsens the spatial point estimate. Sparse scaling extends to 20,000 nodes and separates one-time spectral setup from amortized screening cost. These results characterize the spectral residual as a useful but domain-sensitive inductive bias for structural connectivity screening. Code, cached networks, and reproducibility artifacts are archived at doi:10.5281/zenodo.22307723.

Thu 10 SeptMachine Learning
The gist
Estimating how road network disruptions reduce connectivity is challenging because exact calculations are slow. The authors use graph neural networks to quickly predict connectivity loss after multiple road closures by correcting simpler mathematical estimates. They test their approach on synthetic data and real road maps from various countries, finding their method improves accuracy while scaling to large networks. The results show the approach works best when disruption patterns are similar to the training data and highlight limits when transferring between different regions.
Open → 2609.11166v1

Foundation model embeddings improve urban livability predictions

Applying foundation model embeddings towards urban livability evaluation

Abstract: While accurate measurement of socioeconomic indicators remains challenging in data-scarce regions, which limits policy interventions and resource allocation, high-resolution geospatial data is widely available and can contain information on various livability statistics. We investigate which physical features are encoded within foundation model embeddings, such as AlphaEarth, AnySat, and TerraMind, and provide a systematic framework for identifying the most predictive geospatial indicators. By analyzing how different types of geospatial data influence urban livability predictions, our approach enables researchers to prioritize the most informative features for their specific applications. Additionally, we demonstrate how to leverage foundation model embeddings to enhance prediction performance for these outcomes. This work contributes a principled methodology for extracting actionable information from satellite imagery while accounting for complex spatial dependencies, with applications in predicting urban livability in regions with limited observation data.

Tue 8 SeptMachine LearningComputers and Society
The gist
Measuring how livable a city is can be hard in places without much data. The authors look at special AI tools called foundation model embeddings that analyze satellite images to find clues about cities’ livability. They found a way to pick the best types of satellite data to make these predictions more accurate. This helps people understand which city features matter most for making places better to live, especially where traditional data is missing.
Open → 2609.09429v1

Dual-prior network improves clearing haze in remote sensing images

DPSF-Net: A Dual-Prior Spatial-Frequency Network for Real-World Remote Sensing Image Dehazing

Abstract: Real-world remote sensing image dehazing (RSID) remains challenging because atmospheric scattering, spatially non-uniform haze and colour distortion jointly degrade structural and spectral information. Most deep learning methods rely on RGB inputs and spatial-domain feature extraction, which limits their ability to separate global background haze from local surface details. Here, we propose DPSF-Net, a dual-prior spatial-frequency network built on MCAF-Net for real-world RSID. The network uses hazy RGB images and dark channel prior (DCP) maps as joint inputs, allowing physical degradation cues to guide end-to-end feature learning. A spatial-frequency residual interaction block introduces a FourierUnit branch into multi-directional spatial interaction to model large-scale haze components. A prior-guided feature attention module adaptively fuses prior and attention features to reduce colour shift and structural distortion. A selective kernel complementary fusion module screens multi-scale skip features through bidirectional residual complementary gating and selective kernel fusion. Extensive experiments demonstrate that DPSF-Net achieves state-of-the-art performance on the real-world RRSHID remote sensing image dehazing benchmark and remains competitive across multiple synthetic datasets. Moreover, the proposed method strikes a favourable balance among restoration quality, parameter count and computational complexity, supporting the effectiveness of dual-prior spatial-frequency modelling.

Mon 7 SeptComputer Vision and Pattern RecognitionArtificial Intelligence
The gist
Hazy conditions in satellite and aerial images make it hard to see details clearly and can distort colors. The authors created a computer method called DPSF-Net that uses both the usual color images and special maps showing haze patterns to clean up these images better. Their approach combines features from the image and its frequency details to separate large hazy areas from important local details. Tests showed that DPSF-Net works very well on real-world hazy remote sensing images and keeps a good balance between quality and computing cost.
Open → 2609.06962v1