Geospatial Data

5 posts

google3 min readCurated summary

Expanding our Heat Resilience data to 50+ global cities

Google Research has expanded its building-level rooftop reflectivity dataset from 14 pilot cities to more than 50 cities across nine countries. By combining Sentinel-2 satellite data with 30-centimeter commercial imagery and machine learning, the project identifies roofs where reflective “cool roof” interventions could reduce urban heat. The data is publicly available through a new Google Earth Engine app for planners and researchers. ## Why Rooftop Reflectivity Matters - Extreme heat contributes to approximately 500,000 deaths annually. - Urban heat islands make cities warm faster than the global average. - Dark roofs, pavements, and limited vegetation increase heat absorption. - Reflective roofs reduce the solar energy absorbed by buildings and can lower local surface temperatures. - Earlier pilot data from 14 cities supported cool-roof ordinances and broader climate adaptation plans. ## Building-Level Albedo Mapping - Sentinel-2 provides global albedo data but at 10-meter resolution, which cannot reliably distinguish individual rooftops. - Google Research fused Sentinel-2’s spectral and global coverage with 30-centimeter Airbus Pléiades Neo imagery. - Machine learning and radiometric calibration reconstruct detailed reflectance profiles at the urban-pixel level. - Validation against airborne hyperspectral measurements in Boulder, Colorado, produced an RMSE of 0.04. - The resulting maps allow planners to prioritize large, low-reflectivity buildings for cool-roof retrofits. - The modeling suggests targeted interventions could reduce extreme urban heat by up to 0.5°C globally. ## Heat Resilience Earth Engine App - Displays building-level albedo using rooftop centroids to highlight low-reflectivity surfaces. - Provides baseline analyses and supports monitoring changes over time. - Allows users to download high-resolution data for local studies and policy development. - Offers a nested view that moves from census-tract summaries to individual buildings. ## Expanded Global Coverage - The dataset now covers more than 50 cities in nine countries. - Newly included urban areas span Europe, Brazil, and the United States. - Examples include London, Athens, Barcelona, Rio de Janeiro, São Paulo, Los Angeles, Austin, and New York City. - The open dataset is intended to help municipalities accelerate reflective-surface programs. ## Access and Collaboration - The interactive app and datasets are publicly available through Google’s Heat Resilience site. - The methodology is described in the Nature Communications paper “Estimating high-resolution albedo for urban applications.” - The work was developed by Google Research in collaboration with the World Resources Institute. Cities can use the app to identify the buildings and neighborhoods where cool-roof investments are likely to have the greatest heat-reduction benefits.

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google3 min readCurated summary

From pixels to planning: Earth AI for nature restoration

Google Research developed a high-resolution AI system that converts satellite imagery into vector data identifying small ecological features such as hedgerows, stone walls, and copses. These features can store carbon and support biodiversity without taking agricultural land out of production, but they are often missed by conventional forest inventories. The resulting open dataset aims to make fine-scale nature restoration measurable and actionable across the UK. ## The case for fine-scale restoration - Forests support carbon sequestration, water filtration, and biodiversity, but expanding forests can compete with food production. - Conservation efforts can also create “leakage,” shifting environmental damage elsewhere. - Hedgerows, shelterbelts, and other woody features offer ecological benefits while remaining integrated into farmland. - Google’s earlier **Farmscapes 2020** raster map detected these features across England, but pixel data was insufficient for planning, restoration, and carbon accounting. ## Challenges in mapping the countryside - Agricultural features often overlap spatially, such as hedgerows growing alongside or over stone walls. - Processing data in S2-cell tiles can split features at tile boundaries. - A generic “woody” classification does not reveal whether a feature is a forest, wildlife corridor, or isolated copse. - England’s more than 130,000 km² of high-resolution imagery created major computational demands for conventional raster-to-vector processing. ## Deep learning and vectorization - The team fine-tuned Remote Sensing Foundations’ Vision Transformer, pretrained on more than 300 million global satellite images. - Only about 247 km² of annotated British landscape data was available, so the pretrained model helped transfer broad visual knowledge to local conditions. - A dual-layer labeling system combined submeter imagery with 1-meter LiDAR to distinguish: - Ground-level boundaries such as fields and water - Above-ground features such as trees and walls - Geometry-merging algorithms reconnected features split across S2-cell borders. ## Classifying ecological features - The system used the **Polsby–Popper compactness score** to classify detected shapes by geometry. - Woodlands were defined as contiguous canopies at least 30 meters in diameter. - Woody patches included small copses and individual trees. - Linear woody features, including hedgerows and corridors, were identified using a compactness score below 0.5. - This classification turns raw detections into an inventory tied more closely to ecological function. ## Scaling the analysis - Google Earth Engine processed thousands of S2 cells in parallel. - This made it possible to generate vector geometries for millions of features across England without overwhelming traditional systems. - The resulting dataset is intended for landowners, conservationists, scientists, and policymakers. ## Future applications - The researchers plan to apply the method to silvopasture and agrisilviculture. - High-precision monitoring could help detect conservation “leakage” beyond project boundaries. - Open access to the data could support restoration while protecting agricultural productivity and food security. The dataset provides a practical foundation for planning and measuring nature recovery on working lands, demonstrating how AI can translate overlooked landscape details into conservation decisions.

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google3 min readCurated summary

Mapping the modern world: How S2Vec learns the language of our cities

S2Vec is a self-supervised framework that converts buildings, roads, businesses, and infrastructure into general-purpose geospatial embeddings. By rasterizing these features into S2 Geometry cells and training a masked autoencoder to reconstruct missing areas, it learns the spatial “character” of neighborhoods without manually labeled data. It performs especially well for socioeconomic predictions in geographically unseen regions, while environmental tasks benefit from combining it with satellite imagery. ## Turning Geospatial Data into Images - Geospatial data is multimodal and unevenly distributed: urban blocks may contain hundreds of features, while rural areas contain few. - S2Vec uses hierarchical S2 Geometry cells to divide the Earth into regions at different resolutions. - It counts feature types within each cell—such as buildings, parks, roads, and businesses—and organizes them into multilayered raster images. - This makes complex geographic information compatible with computer vision methods developed for ordinary images. ## Learning with Masked Autoencoding - S2Vec masks portions of the rasterized map and trains a model to reconstruct the missing features from surrounding context. - Repeated training across global locations teaches relationships among urban elements, such as the likelihood of shops near residential buildings and transit stations. - The resulting embeddings are compact numerical representations of each location’s built environment. - Because training is self-supervised, S2Vec does not require worldwide labels for income, air quality, population, or other metrics. - The model can identify similar neighborhood types without being explicitly told concepts such as “financial district” or “suburban residential area.” ## Evaluation and Socioeconomic Performance - S2Vec was compared with models including SATCLIP, GEOCLIP, RS-MaMMUT, Hex2vec, and GeoVeX. - Tests covered population density, median income, carbon emissions, tree cover, and elevation. - Models were evaluated using mean squared error and both: - Interpolation, using random train/test splits - Extrapolation, predicting conditions in geographically unseen regions - S2Vec was generally the strongest individual model for zero-shot socioeconomic prediction, including population density and median income. - It performed competitively with established image-based approaches and exceeded GEOCLIP in the reported comparisons. ## Benefits of Multimodal Fusion - Combining S2Vec with satellite-image embeddings generally produced better results than either modality alone. - Built-environment data captures structures and infrastructure, while satellite imagery adds information about vegetation, terrain, and transportation patterns. - Fusion was particularly valuable for environmental prediction tasks. ## Limitations on Environmental Tasks - Built-environment features alone do not fully explain factors such as tree cover and elevation. - S2Vec was competitive for carbon-emissions prediction but weaker on some environmental metrics. - Satellite imagery embeddings improved performance by supplying information unavailable from counts of buildings, roads, and businesses. S2Vec points toward scalable geographic foundation models that replace task-specific feature engineering with reusable representations. In practice, it is most effective when its built-environment embeddings are combined with complementary imagery, especially for environmental analysis.

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coupangOriginal article

Coupang Rocket Delivery’s spatial index-based delivery management system (opens in new tab)

Coupang’s Rocket Delivery system recently transitioned from a text-based postal code infrastructure to a sophisticated spatial index-based management system to handle increasing delivery density. By adopting Uber’s H3 hexagonal grid system, the engineering team enabled the visualization and precise segmentation of delivery areas that were previously too large for a single driver to manage. This move has transformed the delivery process into an intuitive, map-centric operation that allows for data-driven optimization and real-time area modifications. ### Limitations of Text-Based Postal Codes * While postal codes provided a government-standardized starting point, they became inefficient as delivery volumes grew from double to triple digits per code. * The lack of spatial data meant that segmenting a single postal code into smaller units, such as individual apartment complexes or buildings, required manual input from local experts familiar with the terrain. * Relying on text strings prevented the system from providing intuitive visual feedback or automated metrics for optimizing delivery routes. ### Adopting H3 for Geospatial Indexing * The team evaluated different spatial indexing systems, specifically comparing Google’s S2 (square-based) and Uber’s H3 (hexagon-based) frameworks. * H3 was chosen because hexagons provide a constant distance between the center of a cell and all six of its neighbors, which simplifies the modeling of movement and coverage. * The hexagonal structure minimizes "edge effect" distortions compared to squares or triangles, making it more accurate for calculating delivery radius and area density. ### Technical Redesign and Implementation * The system utilizes H3’s hierarchical indexing, allowing the platform to store delivery data at various resolutions to balance granularity with computational performance. * Delivery zones were converted from standard polygons into "hexagonized" groups, enabling the system to treat complex geographical shapes as sets of standardized cell IDs. * This transition allowed for the creation of a visual interface where camp leaders can modify delivery boundaries directly on a map, with changes reflected instantly across the logistics chain. By shifting to a spatial index, Coupang has decoupled its logistics logic from rigid administrative boundaries like postal codes. This technical foundation allows for more agile resource distribution and provides the scalability needed to handle the continued growth of high-density urban deliveries.

coupangOriginal article

Coupang Rocket Delivery: A (opens in new tab)

Coupang transitioned its Rocket Delivery management from a text-based zip code system to a spatial index-based system using Uber’s H3 library. This shift addresses the limitations of zip codes, which became too coarse for high-density delivery areas, by enabling precise, map-based visualization and manipulation of delivery zones. By adopting a hexagonal grid-based approach, Coupang has improved operational flexibility and its ability to handle complex urban delivery environments. ### The Limitations of Zip Code Systems * Zip codes originally served as the base unit for Rocket Delivery, but as delivery volumes scaled, individual codes became too large for a single driver to manage. * Sub-dividing these areas (e.g., splitting a zip code into specific apartment complexes or even individual buildings) required the manual expertise of senior managers because text-based addresses lack inherent spatial intelligence. * The previous reliance on text made it difficult to visualize delivery boundaries or reassign areas quickly in response to changes in order volume. ### Implementing H3 for Geospatial Indexing * To modernize the system, Coupang adopted H3, a hexagonal hierarchical geospatial indexing system that converts geographic coordinates into unique cell identifiers. * Hexagons were selected over square grids because they provide uniform distances between the center of a cell and all its neighbors, which minimizes distortion in distance-based calculations. * The system uses H3’s hierarchical structure to manage different levels of detail, allowing the platform to aggregate small hexagonal units into larger, custom-defined delivery polygons. ### Technical Challenges in System Redesign * A primary engineering hurdle was selecting the optimal grid resolution to ensure cells were small enough to capture individual building footprints without creating excessive data overhead. * The team developed algorithms to transform groups of hexagonal indices into filled polygons, enabling camp managers to "draw" and modify delivery zones directly on a digital map. * By basing the system on spatial coordinates rather than administrative text, the platform can dynamically adjust to urban changes, such as the construction of new high-rises or the demolition of old structures. Transitioning from text-based addressing to hexagonal indexing allows logistics platforms to move beyond the constraints of administrative boundaries. For high-density urban delivery services, adopting a spatial-first infrastructure like H3 is a necessary step to ensure scalability and operational precision.