Pass log
Every NISAR pass over the area. Each strip leans the way the satellite was flying and is split by how many communities were connected, at risk or isolated. The line is the official river level at the town gauge.
- Isolated
- At risk
- Connected
- Pass covers part of the area: image only
- River level (cm)
On this pass
Pick a community
Select a community on the map or in the list to see its water route on every pass.
How the radar decides
Calm water reflects the radar pulse away from the satellite and shows up dark. On every pass we map that water at 20 m, look for a continuous water path from each community's landing to Tefé, and measure the narrowest point of that path.
A community counts as isolated only when two passes in a row show no water route. Places that never show a route the radar can resolve, and places away from any water, are left out of the counts.
The radar sees water, not depth. A channel can still be there and be too shallow for boats, which is why routes narrower than 60 m are flagged as at risk. Check against river gauges and local reports before acting.