Sea level Measurements Made by Earth Observation Satellites

CEOS EO HANDBOOK – MEASUREMENT INSTRUMENTS

Measurements > Ocean >
Ocean topography/currents >
Sea level

Measurement Definition*: Actual, local sea level inclusive of mean sea level and perturbations (tides, etc.) [Unit of measurement - cm]

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ECV Sea Level

Instrument	Status/ Accuracy	Instrument Description	Measurement Technology	Timeline
ALT Radar Altimeter	Operational	Global ocean topography, sea level and gravity field measurements.	n/a
AltiKa Ka-band Altimeter	Operational	Sea surface height.	n/a
AMR Advanced Microwave Radiometer	Operational	Altimeter data to correct for errors caused by water vapour and cloud-cover. Also measures total water vapour and brightness temperature.	n/a
AMR-C Advanced Microwave Radiometer for Climate	Operational	Capabilities of the AMR with the addition of an on-board calibrator for high stability wet-tropospheric path delay correction.	n/a
AMR-S AMR-S Two-Beam Microwave Radiometer	Operational	Capabilities of the AMR with the addition of a 2nd beam to provide wet-tropospheric path delay correction within both swaths of the primary radar instrument (KaRIn)	n/a
DORIS-NG Doppler Orbitography and Radio-positioning Integrated by Satellite-New Generation	Operational	Precise orbit determination; Real time onboard orbit determination (navigation).	n/a
GPSP Global Positioning System Payload	Operational	Precision orbit determination.	n/a
Ka-band Radar Interferometer (KaRIn) Ka-band Radar Interferometer (KaRIn)	Operational	Swath mapping radar altimeter that provides measurements for surface water.	n/a
LRA Laser Retroreflector Array	Operational	Baseline tracking data for precision orbit determination and/or geodesy. Also for calibration of radar altimeter bias. Several types used on various missions. (ASI involved in LAGEOS 2 development).	n/a
POSEIDON-3B Altimeter Positioning Ocean Solid Earth Ice Dynamics Orbiting Navigator (Single frequency solid state radar altimeter)	Operational	Nadir viewing sounding radar for provision of real-time high precision sea surface topography, ocean circulation and wave height data.	n/a
POSEIDON-3C Altimeter Positioning Ocean Solid Earth Ice Dynamics Orbiting Navigator (Single frequency solid state radar altimeter)	Operational	Nadir viewing sounding radar for provision of real-time high precision sea surface topography, ocean circulation and wave height data.	n/a
Poseidon-4 Altimeter Poseidon-4 SAR Radar Altimeter	Operational	Nadir viewing sounding radar for provision of real-time high-precision sea surface topography, ocean circulation and wave height data.	n/a
SRAL SAR Radar Altimeter	Operational	Marine and land services.	n/a
IRIS Interferometric Radar Altimeter for Ice and Snow	Being developed	Ku-band Interferometric Synthetic Aperture Radar Altimeter (with added Ka-band channel for snow depth retrieval and in combination with AMR-CR MW Radiometer for ice&snow classification and wet troposphere correction) to cover the needs for continuous monitoring of sea ice thickness and land ice elevation measurement after Cryosat-2, with enhanced performance.	n/a
Poseidon-5 Altimeter Poseidon-5 SAR Radar Altimeter	Being developed		n/a
SAOOH Swath Altimeter for Oceanography and Operational Hydrology	Being developed		n/a
AMR-CR Advanced Microwave Radiometer for Climate	Approved	Capabilities of the AMR with the addition of an on-board calibrator for high stability wet-tropospheric path delay correction and a redesign with respect to AMR-C (i.e. the 3 high res MW radiometer channels at 90, 130 and 166 GHz are an integral subsystem of the instrument and not experimental as in AMR-C)	n/a
LTI Laser Tracking Instrument	Approved	The aim of MAGIC is to obtain high-resolution measurements in space and time and include the capability to determine the variations in gravity field due to mass change in hydrology, cryosphere, oceanography, solid Earth and climate change signals so as to serve science and operational products including emergency services.	n/a

* Description adapted from WMO.