Datasets & Scientific Methodology
Detailed technical documentation of the federal open datasets, Earth observation satellite instruments, and analytical pipelines powering HomeTruth.
NASA Space Apps 2026: Earth Science for Human Resilience
Challenge Theme: Translating Earth Observation into Real-World DecisionsThe 2026 NASA Space Apps Challenge challenges developers and scientists to liberate planetary-scale satellite datasets so everyday citizens can navigate catastrophic environmental shifts. HomeTruth addresses the most consequential financial decision an individual or family makes: where to live. By combining NASA orbital instruments with USGS seismic databases and FEMA flood boundaries, we bridge the critical divide between astrophysics and residential real-estate due diligence.
How Property Exploration Works
The automated pipeline connecting raw user search inputs to multi-agency open science.
U.S. Census Geocoding
Matches the candidate address against the Census Bureau Geocoder, extracting precise coordinates and official 11-digit Census Tract FIPS identifiers.
FEMA NRI & USGS Overlays
Retrieves authentic tract boundaries via ArcGIS FeatureServer, evaluating Expected Annual Loss for riverine floods, storm surge, wildfires, and fault acceleration.
NASA POWER Climate Series
Ingests 25 years of monthly satellite temperature and precipitation telemetry with SciPy linear regressions, p-values, and 95% confidence intervals.
Verified Federal Datasets & API Integrations
Complete inventory of genuine public sources utilized by HomeTruth, detailing purpose, spatial resolution, and known limitations.
U.S. Census Bureau Geocoding Service
Converts raw user-entered street addresses into precise geographic coordinates (WGS84 latitude/longitude) and official 11-digit Census Tract FIPS identifiers.
Address range / parcel point resolution (Benchmark: Public_AR_Current / Census2020_Current).
Requires standardized postal street addresses; rejects unrecognized private ways or PO Boxes. Does not provide parcel boundaries or interior architectural records.
FEMA National Risk Index (NRI)
Retrieves official community-level multi-hazard risk ratings, Expected Annual Loss (EAL) scores, and historical hazard exposure for Inland Flood, Coastal Flood, Wildfire, and Earthquake.
Census Tract level with genuine MultiPolygon boundaries via official ArcGIS FeatureServer.
Models community-wide baseline exposure across an entire tract, not an individual building elevation certificate or flood vent configuration. Missing hazards are preserved as such and never coerced to low risk.
NASA POWER Project (MERRA-2 Reanalysis)
Ingests 25 years (2001–2025) of monthly 2-meter air temperature (T2M) and precipitation totals (PRECTOTCORR). Evaluated with SciPy linear trend regressions, p-values, and 95% confidence intervals.
0.5° × 0.5° global latitude/longitude grid derived from NASA satellite assimilation models.
Represents observed multi-decade meteorological shifts rather than deterministic microclimate guarantees or future catastrophic storm predictions.
USGS Earthquake Hazards Program & Real-Time Feed
Queries live seismic events within a 200 km radius of candidate properties and integrates National Seismic Hazard Model (UCERF3) ground motion probabilities.
Individual earthquake hypocenters and regional fault trace geometries.
Indicates historical and probabilistic crustal ground shaking; does not inspect building soft-story framing, anchor bolting, or localized soil liquefaction without on-site geotechnical engineering.
Tiger Data (TimescaleDB / PostgreSQL Hypertable)
Persists monthly NASA observations in an optimized PostgreSQL hypertable, utilizing time_bucket() analytical aggregations to eliminate redundant satellite requests.
Regional coordinate bounding boxes partitioned by year and month.
Cache lifecycle aligned with monthly NASA POWER data updates.
Google Gemini 3.5 AI Engine
Translates verified FEMA hazard ratings, NASA trend statistics, and user housing preferences (renter vs. buyer, floor level, basement) into actionable due-diligence questions and practical preparedness steps.
Structured JSON schema validated against strict data bounds.
Bound strictly to verified federal inputs; prohibited from inventing disaster probabilities, insurance quotes, or property damage claims.
Core Earth Observation Satellite Missions
HomeTruth leverages multi-spectral radiometers, radar interferometry, and thermal radiometers.
Provides near-real-time 375m active fire detections and Fire Radiative Power (FRP). Used to calculate historical burn perimeters, fuel ignition frequency, and ember drift buffers around residential communities.
Surface Water and Ocean Topography (SWOT) uses Ka-band radar interferometry to measure inland water heights, river discharges, and coastal storm surges at 2-kilometer coastal resolution.
ECOsystem Spaceborne Thermal Radiometer Experiment on Space Station measures plant canopy water stress and land surface skin temperatures at 70m resolution, pinpointing micro-urban heat islands.
Ingests Uniform California Earthquake Rupture Forecast 3 and radar interferometric crustal deformation maps to model 30-year ground motion probabilities and active fault trace proximity.
Composite Risk Scoring & AI Assessment Architecture
Weighted hazard vectors and life-impact translation engine.
The HomeTruth Composite Disaster Index (0–100) is synthesized using an asymmetric hazard-weighting model. Catastrophic structural hazards (Flood & Wildfire) are weighted heavily because they represent total property loss risk, while chronic stressors factor heavily into the AI Life Impact Rating:
Scientific Limitations & Ethical Disclaimers
Understanding data resolution, micro-topography, and structural caveats.
While HomeTruth harnesses industry-leading Earth Observation datasets, several scientific boundaries exist:
- Spatial Resolution: Planetary satellite sensors operate on pixel footprints ranging from 30 meters (Landsat) to 0.5 degrees (MERRA-2). Sub-parcel micro-drainage (e.g. driveway swales, retaining walls, localized street crowns) can alter specific water flow paths.
- Internal Structural Condition: Satellite telemetry cannot inspect private interior home systems, such as whether previous homeowners installed seismic cripple wall strapping, French drains, or fire-resistant attic baffle mesh.
- Community vs. Parcel Baseline: FEMA NRI data maps expected losses across entire census tracts. On-site risk varies by specific foundation elevation above base flood elevation (BFE).
Ready to run an environmental audit on a property?
Test any U.S. street address on our Explore page to see Census geocoding, FEMA hazard ratings, and NASA satellite observations in action.