Satellite Data Sources
Every data source behind the Map, the Watchfloor, and Delta Agent — what it is, how sharp it is, how often it refreshes, and how to credit it. All open data, all in your browser.
Quick answer — which data sources are available
Imagery — Sentinel-2 optical (10 m, 13 bands), Sentinel-1 C-band SAR (10 m, VV/VH), NISAR L-band SAR (10 m, HH/HV, provisional calibration), VIIRS nighttime lights (NASA Black Marble, ~500 m), and NASA FIRMS active fire (375 m, daily). Event intelligence — worldwide news-event signals via the GDELT Project (with links to original sources), GDACS tropical cyclones, Open-Meteo weather/observability, and OpenStreetMap · NASA GIBS basemaps, all AI-enriched and geolocated (no human review). You can also upload your own GeoTIFF, COG, or GeoJSON data.
Satellite Imagery
Sentinel-2 Optical
OpticalESA Copernicus Programme
High-resolution multispectral optical imagery. Thirteen spectral bands from visible through near-infrared and shortwave infrared make it the workhorse for vegetation, land cover, and water analysis.
Resolution
10 m (visible/NIR)
Bands
13 spectral bands
Revisit
~5 days (constellation)
Level
L2A surface reflectance
Typical uses: True color and false color composites, NDVI / EVI / NDWI vegetation and water indices, crop and forest monitoring, land-cover change.
Attribution: Contains modified Copernicus Sentinel data [year]
Open Sentinel-2 ViewerSentinel-1 C-Band SAR
RadarESA Copernicus Programme
C-band Synthetic Aperture Radar that images the surface day or night and sees straight through cloud, smoke, and light rain. Delivered as GRD products in VV and VH polarizations.
Resolution
~10 m (IW mode)
Polarization
VV, VH
Revisit
6-day repeat cycle
Frequency
C-band, 5.405 GHz
Typical uses: Flood mapping, surface-change detection, vessel detection, and all-weather monitoring where optical imagery is blocked by clouds.
Attribution: Contains modified Copernicus Sentinel data [year]
Open Sentinel-1 SAR ViewerNISAR L-Band SAR
RadarNASA / ISRO, distributed by ASF DAAC
L-band Synthetic Aperture Radar from the joint NASA-ISRO mission. Its ~24 cm wavelength penetrates vegetation canopy that C-band radar only sees the top of, reaching branches, trunks, and the ground beneath. Delivered as geocoded covariance (GCOV) products in HH and HV polarizations.
Resolution
10 m (frequency A)
Polarization
HH, HV
Revisit
12-day repeat cycle
Frequency
L-band, 1.239 GHz
Typical uses: Forest structure and biomass, flooding under tall canopy, and change detection where C-band loses coherence over vegetation.
Note: The public NISAR collection is provisionally calibrated. Backscatter values should be read as indicative rather than measured.
Attribution: Contains NASA/ISRO NISAR data processed by ASF DAAC
Open NISAR L-Band ViewerVIIRS Nighttime Lights
NighttimeNASA Black Marble (VNP46A2)
The VIIRS Day/Night Band measures visible light at night. NASA Black Marble products are calibrated and atmospherically corrected, turning city lights into a proxy for human activity.
Resolution
~500 m
Product
Black Marble VNP46A2
Revisit
Daily
Sensor
VIIRS Day/Night Band
Typical uses: Tracking urban development and electrification, estimating economic activity, and detecting power outages after disasters.
Attribution: NASA Black Marble VNP46A2
Open Nighttime LightsNASA FIRMS Active Fire
Active FireNASA FIRMS
Near real-time thermal fire detections from VIIRS and MODIS. Hotspots are updated daily and overlaid directly on the map — no account or API key required to browse.
Resolution
375 m (VIIRS), 1 km (MODIS)
Latency
Near real-time, daily
Sensors
VIIRS, MODIS thermal
Cost
Free to browse
Typical uses: Wildfire situational awareness, monitoring fire spread, and correlating thermal anomalies with events on the Watchfloor.
Attribution: NASA FIRMS
Open Active Fire MapYour Own Data
Bring Your OwnUploaded by you
Bring GeoTIFF, Cloud-Optimized GeoTIFF, or GeoJSON files and combine them with satellite imagery on a single map. Your data stays alongside the open sources for custom analysis.
Raster
GeoTIFF, COG
Vector
GeoJSON
Use
Overlay with satellite layers
Reference
OpenStreetMap basemaps
Typical uses: Overlaying field boundaries, custom AOIs, survey results, or third-party rasters together with Sentinel and VIIRS imagery.
Attribution: You retain ownership of uploaded data
Upload Your DataEvent, Weather & Context Data
What powers the Watchfloor, Delta Agent, and Reports — the news-event stream, its original sources, hazards and weather, the reference basemap, and how signals are enriched and geolocated.
Global Event Signals
Event IntelligenceGDELT Project (open data)
A continuous, worldwide stream of geolocated event signals distilled from global news media. This is the backbone of the Watchfloor, Delta Signals, the daily Reports, and the Event Intelligence API.
Update
Continuous (~15 min feed)
Latency
Minutes to hours
Coverage
Global, multilingual
License
GDELT open data
Typical uses: Discovering emerging events, screening a region or topic, and deciding what to confirm with satellite imagery. Dates are news-reported days (not verified occurrence).
Attribution: Event data derived from the GDELT Project
Open the WatchfloorOriginal News Sources
Source LinksGlobal news media
Every signal links back to the originating news article(s) so a judgment can be traced to its source, and Reports cite these directly. Where several outlets cover an event, the most authoritative is shown.
Update
Per event
Sources
One or more per event
Access
Public article URLs
Rights
Held by each publisher
Typical uses: Verifying a signal against its origin, and following a Key Judgment to the reporting behind it. Link availability and source reliability vary by event.
Attribution: Article rights held by their publishers
Tropical Cyclones
HazardsGDACS (EC JRC / UN)
Active tropical-cyclone tracks and alert levels, overlaid on the map for maritime and coastal situational awareness.
Update
As alerts are issued
Coverage
Global active storms
Type
Tracks + alert level
License
GDACS open data
Typical uses: Anticipating disruption to shipping, ports, and coastal infrastructure, and pairing storm tracks with imagery tasking.
Attribution: Cyclone data courtesy GDACS (EC JRC)
Weather & Observability
WeatherOpen-Meteo
Cloud-cover and visibility outlook used to judge whether an event can realistically be imaged by optical satellites — the observability signal behind collection recommendations.
Update
Hourly forecast
Type
Cloud cover, visibility
Nature
Forecast, not observation
License
CC BY 4.0 (Open-Meteo)
Typical uses: Deciding between optical and all-weather radar for a target, and flagging events that clouds would obscure.
Attribution: Weather data by Open-Meteo.com (https://open-meteo.com/), CC BY 4.0, using DWD ICON and NOAA GFS models.
Basemap, Place Context & Coastline
ReferenceOpenStreetMap · NASA GIBS
OpenStreetMap provides the reference basemap and place context; NASA GIBS serves the daily global browse layers (VIIRS, active fire) rendered on the map. OpenStreetMap land polygons also supply the coastline used to mask land in Ship Detection, with Natural Earth as a fallback.
Basemap
OpenStreetMap
Coastline
OSM land polygons · Natural Earth fallback
Browse tiles
NASA GIBS
Update
OSM continuous · GIBS daily
License
ODbL · Natural Earth public domain · NASA open
Typical uses: Orienting a signal to nearby places, infrastructure, and coastlines; excluding land from maritime vessel detection; and providing daily global context imagery.
Attribution: © OpenStreetMap contributors · NASA GIBS
AI Enrichment & Geolocation
ProcessingOff-Nadir Delta (automated)
Raw news events are automatically classified (category, severity, GEOINT relevance), geolocated with a confidence flag, linked to their sources, and matched to a recommended sensor and resolution. There is no human in the loop.
Steps
Classify · geolocate · link · recommend
Review
Automated, no human review
Confidence
Per-signal geolocation flag
Limits
Can mis-classify / mis-locate
Typical uses: Turning a raw news event into a decision-ready signal with a sensor recommendation. Treat outputs as decision support, not confirmed fact.
Attribution: Enrichment by Off-Nadir Delta
Read the methodology & limitationsAttribution & Licensing
All satellite sources come from free and open programmes. When you export or publish imagery, include the relevant attribution below.
Sentinel-1 & Sentinel-2
European Space Agency (ESA) Copernicus Programme
"Contains modified Copernicus Sentinel data [year]"
VIIRS Nighttime Lights
NASA Black Marble (VNP46A2)
"NASA Black Marble VNP46A2"
NASA FIRMS Active Fire
NASA Fire Information for Resource Management System
"NASA FIRMS"
Basemap & Browse Tiles
OpenStreetMap contributors · NASA GIBS
"© OpenStreetMap contributors · NASA GIBS"
Global Event Signals
GDELT Project
"Event data derived from the GDELT Project"
Tropical Cyclones
GDACS (EC JRC / UN)
"Cyclone data courtesy GDACS (EC JRC)"
Weather & Observability
Open-Meteo
"Weather data by Open-Meteo.com, CC BY 4.0, using DWD ICON and NOAA GFS models."
Your Own Data
Uploaded GeoTIFF / COG / GeoJSON
You retain ownership of uploaded data
Frequently Asked Questions
Where do the Watchfloor signals come from?▼
Is the event and weather data AI-verified?▼
Is the satellite data free?▼
What is the difference between Sentinel-1 and Sentinel-2?▼
How often is each source updated?▼
Do I need to credit the data sources?▼
Can I add my own data?▼
Related Resources
Sentinel-2 Viewer
Free optical imagery
Learn moreSentinel-1 SAR
All-weather radar
Learn moreNighttime Lights
VIIRS Black Marble
Learn moreActive Fire Map
NASA FIRMS hotspots
Learn moreMethodology & Limitations
How signals are made
Learn moreGlossary
Satellite terminology
Learn morePricing
Browse free, pay for depth
Learn moreStart Exploring These Sources
Open Sentinel-1, Sentinel-2, NISAR, VIIRS, and NASA FIRMS data with a free account.
From headline to satellite evidence
One connected intelligence workflow across four surfaces — free to start, no GIS software or remote-sensing background required.