Measurements and Applications
High-resolution measurements of radar backscatter for global estimates of surface soil moisture and freeze/thaw states for climate modeling and weather prediction. The radar instrument stopped transmitting on 7 July 2015.
Full Name
L-band Synthetic Aperture Radar (SMAP)
Status
No longer operational
Instrument Agencies
Maturity
Instrument Type
Imaging microwave radars 
Geometry
Conical scanning
Instrument Technology
Imaging radar (SAR)
Sampling
Other
Data Access
Open Access
Data Format
HDF-5
Resolution
<3 km spatial resolution over 70% of swath; 3 days temporal resolution. Soil moisture will be estimated at a resolution of 10 km and freeze-thaw state at a resolution of 1-3 km.
Swath
40-deg constant incidence angle across the 1000 km swath
[Max Swath: 1000 km]
Accuracy
<1dB Co-polarization; <1.5 dB cross-polarization at 3 km resolution
Waveband
L-Band (1.2 GHz)
| MW (~0.1 cm - ~100 cm) |
| L-Band (2 - 1 GHz) |
Compiled from the 2026 Extended Parameters Survey, agency-nominated technical contacts and published user guides; not yet collected through the annual CEOS MIM survey.
Polarisation Channels
HH · HV · VV · VH
Polarisation Modes
single · dual · quad
Antenna
Offset-fed mesh reflector, 6m diameter — 6 × 6 m
Polarisation Notes
Quad polarisation
Source
2026 Extended Parameters Survey (NASA, 2026-08-18)
Compiled from the 2026 Extended Parameters Survey, agency-nominated technical contacts and published user guides; not yet collected through the annual CEOS MIM survey.
| Mode | Resolution az × rg (m) | Swath (km) | Incidence (°) | Polarisation | NESZ (dB) | Bandwidth (MHz) |
|---|
| Low Resolution Radar L1B_S0_LoRes | 30000 × 5000 | 1000 | 40–40 | HH+VV+HV+VH | -30 | 1 |
| High Resolution Radar L1B_S0_HiRes | 1000 × 1000 | 1000 | 40–40 | HH+VV+HV+VH | -30 | 1 |