🌏 About SAR API

Satellite radar intelligence,
open to everyone.

We believe satellite intelligence shouldn't require a seven-figure contract or a PhD in remote sensing. SAR API turns free, open Sentinel-1 radar data into ready-to-use JSON — floods, dark vessels, oil spills, deforestation, and more — delivered in milliseconds.

The European Space Agency's Sentinel-1 constellation images the entire Earth's surface every six days, in all weather, day and night. It sees through clouds. It sees through darkness. Every scan is published as open data — free to download, free to use.

The problem is the complexity. Processing raw SAR backscatter into meaningful detections requires terrain correction, speckle filtering, land masking, and algorithm expertise. Most organisations simply don't have it. SAR API removes that barrier entirely — you get the intelligence, not the satellite science.

Every six days, our pipeline runs automatically:

1
Sentinel-1 acquisition
New IW GRD scenes are detected via the Copernicus Data Space API and queued for download.
2
Terrain correction (SNAP RTC)
Raw .SAFE archives are processed with ESA's SNAP engine — calibrated, multi-looked, terrain-corrected, and geocoded.
3
Cloud-optimised GeoTIFF
Corrected VV/VH bands are converted to COG and stored in Cloudflare R2 for fast, range-request tile serving.
4
Analysis — flood, vessel, change
Threshold, CFAR, and bi-temporal change detection algorithms run against each scene. Results stored in PostGIS with full geometry.
5
Webhook delivery
Subscribers receive a signed POST request within minutes of new detections intersecting their area of interest.

We're built on top of the Copernicus programme — a publicly funded, open-access Earth observation system operated by ESA and the European Commission. The underlying satellite data is free. What we sell is the processing, the infrastructure, and the developer experience.

🌎
Sentinel-1 data is free and open. Anyone can download it from the Copernicus Data Space. SAR API exists because processing it at scale — reliably, globally, and in near-real-time — is genuinely hard. We handle that so you don't have to.

Flood mapping — SAR backscatter drops sharply over flooded land. We apply Otsu thresholding against permanent water masks to isolate true flood extent, measured in km².

Dark vessel detection — Vessels appear as bright point targets in SAR. We use CFAR (Constant False Alarm Rate) detection to find ships independently of AIS transponders — including those that have gone dark to avoid tracking.

Oil spill detection — Biogenic films and oil slicks suppress surface roughness, creating dark patches in VV polarisation. We distinguish these from wind shadows using texture and context.

Change detection — Deforestation, construction, and burn scars are detected by comparing backscatter ratios between consecutive passes over the same area.

🌈
Sentinel-1
SAR source data
SNAP RTC
SAR processing
🐍
Python + NumPy
Analysis algorithms
📊
PostGIS
Geospatial storage
🌐
Cloudflare R2
COG tile storage
Bun + Elysia
API runtime

Ready to get started?

Free API key, no credit card required. 100 calls/day, 30-day history, global coverage.