Backscatter

The fraction of a radar pulse that bounces straight back to the sensor. SAR images are essentially backscatter maps.

Why it matters

Backscatter strength encodes surface roughness, moisture, and structure — letting radar distinguish calm water from rough water, flooded land from dry, forest from field.

In plain terms

The echo strength: a smooth lake bounces the radar away (dark), a rough or wet surface bounces lots back (bright).