EARTH OBS · AGRI · SAR

NISAR After Launch: Weekly Radar Eyes for Farm, Floods & Faults

What dual-band SAR delivers for crop insurance, landslide risk, groundwater & municipal planning — and how to access early products.
By bataSutra Editorial · September 7, 2025
In this piece:
  • The short: launch, swath, cadence & data policy
  • Farm/floods/faults: where dual-band SAR actually helps
  • Access: Earthdata/ASF (Vertex, APIs) and ISRO pathways
  • Weekly workflow + product map you can reuse

The short

  • Launch: NISAR lifted off on July 30, 2025 aboard GSLV-F16. Its 12-m reflector unfurled during commissioning.
  • What it is: First Earth-obs mission with L-band + S-band SAR; ~240 km swath; 3–10 m mode-dependent resolution; global land/ice coverage roughly every 12 days (average sampling ~6 days using ascending/descending passes).
  • Data: Free & open via NASA’s Earthdata/ASF DAAC (Vertex web UI, Search API, and asf_search Python module).

Farm, floods & faults — where dual bands matter

Agriculture & water

  • Crop insurance L-band penetrates canopy → more reliable planted-area & flood-loss maps under cloud cover.
  • Soil moisture proxies Combined L/S responses improve change detection across growth stages.
  • Groundwater/subsidence Repeated InSAR tracks slow compaction over aquifers & metro corridors.

Disaster & infrastructure

  • Floods Wide swath enables basin-scale extent mapping, independent of monsoon cloud cover.
  • Landslides & quakes cm-level deformation time-series to flag unstable slopes and post-seismic slip.
  • Urban planning Encroachment & subsidence dashboards for city agencies using regular cadence.

How to access NISAR data (early)

  1. Create an Earthdata Login (free) — single sign-on for NASA DAAC downloads.
  2. Use ASF Vertex for search & download (or programmatic access via the ASF Search API / asf_search Python module).
  3. Practice with official NISAR sample products & tutorials (RTC/InSAR/PolSAR workflows).
  4. ISRO channels: watch ISRO’s NISAR page and Bhoonidhi for domestic pathways.

Note Commissioning runs ~90 days post-launch; full science ops ramp through late-2025 as cadence and latencies tighten.

Weekly workflow (editorial/ops)

  1. Define AOIs: districts/basins/slopes; save Vertex queries.
  2. Pull rapid layers first (water extent/RTC) for flood desks; queue InSAR for deformation time-series.
  3. Fuse with rainfall & river gauges; publish a map + delta card for each AOI.
  4. Archive & compare bi-weekly to build your early-warning trendline.

Product map (starter)

ProductWhat you getUse quickly for
RTC (Radiometrically Terrain-Corrected)Backscatter maps (L/S)Flood extent, crop damage, wetness shifts
InSAR (displacement)Phase-based deformationLandslide creep, subsidence, post-quake slip
PolSARPolarimetric featuresCrop type/structure, urban classification

Tutorials & sample products for these workflows are available via Earthdata/ASF resources.

Specs, access links and timelines reflect known mission info as of Sep 7, 2025. Expect refinements as commissioning completes and products move to routine cadence.