| Instrument | Agency | Missions | Status | Type | Measurements &
applications | Technical characteristics |
AltiKa
Ka-band Altimeter | CNES | Current: SARAL
Future: -
Complete: - | Operational | Radar altimeters | Sea surface height. |
| Waveband: | 35.5 - 36 GHz, passive channels (radiometer): 24 (K-band) and 37 (Ka-band) GHz; active radar altimeter: 35 GHz (Ka-band)
MW, Ka-Band, K-Band |
| Spatial resolution: | |
| Swath width: | |
| Accuracy: | |
| Data Access: | Open Access |
| Data Format: | |
|
Ka-band Radar Interferometer (KaRIn)
Ka-band Radar Interferometer (KaRIn) | NASA (CNES) | Current: SWOT
Future: -
Complete: - | Operational | Radar altimeters | Swath mapping radar altimeter that provides measurements for surface water. |
| Waveband: | 35.75 GHz Center Freq / 200 MHz Bandwidth
MW, Ka-Band |
| Spatial resolution: | Vertical resolution is 2 cm |
| Swath width: | 50 km |
| Accuracy: | 8.2 cm height accuracy required |
| Data Access: | Open Access |
| Data Format: | |
|
POSEIDON-3B Altimeter
Positioning Ocean Solid Earth Ice Dynamics Orbiting Navigator (Single frequency solid state radar altimeter) | CNES | Current: Jason-3
Future: -
Complete: - | Operational | Radar altimeters | Nadir viewing sounding radar for provision of real-time high precision sea surface topography, ocean circulation and wave height data. |
| Waveband: | Microwave: Ku-band (13.575 GHz), C-band (5.3 GHz)
Ku-Band, C-Band |
| Spatial resolution: | Basic measurement: 1/sec (6 km along track), Raw measurement: 20/sec (300 m along track)
Best resolution: 300 m |
| Swath width: | On baseline TOPEX/POSEIDON orbit (10 day cycle): 300 km between tracks at equator |
| Accuracy: | Sea level: 3.4 cm, Significant wave height: 0.4 m, Horizontal sea surface wind speed: 1.5 m/s |
| Data Access: | Open Access |
| Data Format: | NetCDF |
|
POSEIDON-3C Altimeter
Positioning Ocean Solid Earth Ice Dynamics Orbiting Navigator (Single frequency solid state radar altimeter) | NASA | Current: SWOT
Future: -
Complete: - | Operational | Radar altimeters | Nadir viewing sounding radar for provision of real-time high precision sea surface topography, ocean circulation and wave height data. |
| Waveband: | Microwave: Ku-band (13.575 GHz), C-band (5.3 GHz)
Ku-Band, C-Band |
| Spatial resolution: | Basic measurement: 1/sec (6 km along track), Raw measurement: 20/sec (300 m along track) |
| Swath width: | On baseline TOPEX/POSEIDON orbit (10 day cycle): 300 km between tracks at equator |
| Accuracy: | Sea level: 3.4 cm, Significant wave height: 0.4 m, Horizontal sea surface wind speed: 1.5 m/s |
| Data Access: | Open Access |
| Data Format: | NetCDF |
|
Poseidon-4 Altimeter
Poseidon-4 SAR Radar Altimeter | ESA (EUMETSAT) (NASA) (CNES) | Current: Sentinel-6 A Michael Freilich, Sentinel-6 B
Future: Sentinel-6 C
Complete: - | Operational | Radar altimeters | Nadir viewing sounding radar for provision of real-time high-precision sea surface topography, ocean circulation and wave height data. |
| Waveband: | Microwave: Ku-band (13.575 GHz), C-band (5.3 GHz)
Ku-Band, C-Band |
| Spatial resolution: | |
| Swath width: | On baseline TOPEX/POSEIDON orbit (10 day cycle): 300 km between tracks at equator. |
| Accuracy: | Sea level: 3.2 cm, Significant wave height: 0.15 m, Horizontal sea surface wind speed: 1.5 m/s |
| Data Access: | Open Access |
| Data Format: | NetCDF-4 |
|
SIRAL
SAR Interferometer Radar Altimeter | ESA | Current: CryoSat-2 | Operational | Radar altimeters | Marine ice and terrestrial ice sheet thickness measurement. |
| Waveband: | Microwave: 13.575 GHz (Ku-Band)
MW, Ku-Band |
| Spatial resolution: | Range resolution 45 cm, along-track resolution 250 m |
| Swath width: | Footprint 15 km |
| Accuracy: | Arctic sea-ice: 1.6 cm/year for 300 km x 300 km cells, Land ice (small scale): 3.3 cm/year for 100 x 100 km cells, Land ice (large scale): 0.17 cm/year for Antarctica size area |
| Data Access: | Open Access |
| Data Format: | |
|
SRAL
SAR Radar Altimeter | ESA (EUMETSAT) (COM) | Current: Sentinel-3 A, Sentinel-3 B
Future: Sentinel-3 C, Sentinel-3 D
Complete: - | Operational | Radar altimeters | Marine and land services. |
| Waveband: | Dual freq radar altimeter, Ku-band, C-band
MW, Ku-Band, C-Band |
| Spatial resolution: | 300 m
Best resolution: 300 m |
| Swath width: | Profiling |
| Accuracy: | 3 cm in range (1 s average, 2 m SWH including atm. corrections) |
| Data Access: | Open Access |
| Data Format: | |
|