Inside our oil-spill detector

Oil on water is the classic SAR detection problem: the slick suppresses surface roughness and shows up as a dark patch in C-band backscatter. The hard part isn't seeing the slick. It's separating it from natural look-alikes — algal mats, river plumes, wind shadows, low-wind zones.

The fusion architecture

Three stages:

1. Candidate detection on Sentinel-1 GRD, thresholded against a wind-modulated background.
2. Optical confirmation using the nearest cloud-free Sentinel-2 pass within a configurable time window.
3. Look-alike scoring with a small transformer over local context.

We'll publish numbers on each stage in follow-ups.