How to use ELI
Analyze any location on Earth with real Sentinel-2 satellite imagery. No GIS experience needed.
Getting started
1
Draw an area on the map
Use the rectangle, polygon, or circle tool in the sidebar to select a region. Keep it under 25,000 km² for best results.
2
Pick a date
Sentinel-2 imagery takes about 14 days to process, so the most recent available date is auto-selected. Imagery is available from June 2015 onward.
3
Choose an analysis
Pick from 15+ satellite indices organized into categories: vegetation, fire, water, and land. Hover over any button to see what it measures.
4
View results & export
Results appear in the side panel with key metrics, a map overlay, and an AI interpretation. Export as PDF, CSV, GeoTIFF, or share a link.
Available analyses
NDVI
Vegetation health and density using red & infrared light
Forest Health
Overall forest condition combining moisture and vegetation
EVI
Enhanced vegetation for dense canopy and tropical forests
SAVI
Vegetation in arid areas where soil affects readings
Fire Risk
Wildfire danger scored 1-10 using vegetation dryness
Burn Ratio (NBR)
Identifies areas that have been recently burned
Burn Severity (dNBR)
Compares pre/post fire imagery to measure severity
Water (NDWI)
Detects lakes, rivers, and reservoirs
Moisture (NDMI)
Water content in vegetation — low values mean drought stress
Drought
Drought severity from vegetation stress and moisture deficit
Snow (NDSI)
Maps snow and ice coverage
Land Cover
Classifies vegetation, water, urban, and bare soil
Heat Island
Estimates surface temperature for urban hot spots
Bare Soil (BSI)
Exposed ground, construction sites, eroded areas
Change Detection
Compares two dates to find land surface changes
Common questions
What satellite data does ELI use?
ELI uses Sentinel-2 L2A imagery from the European Space Agency, accessed via the Element84 STAC API. This is free, open data with 10-meter resolution and global coverage every 5 days. No API key or authentication is required.
Why can't I select today's date?
Sentinel-2 imagery goes through atmospheric correction and quality processing before becoming available. This typically takes about 14 days. The date picker automatically selects the most recent date likely to have imagery.
What happens with cloudy images?
ELI automatically checks cloud cover using the Scene Classification Layer (SCL). If the selected scene has more than 30% cloud cover over your area, it tries up to 3 alternative scenes. Cloud-covered pixels are masked from calculations, and the cloud percentage is reported in your results.
Why is there a maximum area size?
The 25,000 km² limit prevents timeouts when downloading satellite imagery. Smaller areas process faster and produce more detailed results.
What export formats are available?
PDF reports with maps and interpretation, CSV with raw data, GeoTIFF for GIS software, and shareable links that anyone can view without an account.
What does "Ask ELI" do?
After running an analysis, you can chat with ELI — an AI assistant that understands your results. Ask follow-up questions like "Is this NDVI normal for this region?" or "What could cause these moisture patterns?" and get contextual answers grounded in your data.