Delay Doppler Mapping Instrument
To observe ocean surface roughness, from which wind speed is retrieved.
System of GPS receivers embarked on a constellation of eight micro-satellites, to receive signals both directly from a GPS satellite by a zenith-pointing antenna, and after reflection from the sea surface by two nadir-pointing antennas.
Scanning provided by the changing relative position of the LEO and the GPS satellites.
Coverage / Cycle
All-longitudes for latitudes < 35°
Flown on an R&D satellite
2017 to ≥2023
Satellites this instrument is flying on
Note: a red tag indicates satellites no longer operational, a
green tag indicates operational satellites, a blue tag indicates
Other payload component Positioning system
Subcomponent 2 Constellation of GNSS receivers [for reflectometry]
Primary mission objectives
Wind speed (near surface) Opportunity objectives Show all Show fewer
Tentative Evaluation of Measurements
The following list indicates which measurements can
retrieved from this category of instrument. To see a full Gap Analysis by Variable,
click on the respective variable.
Note: table can be sorted by clicking on the column headers
Variable Relevance for measuring this variable Operational limitations Explanation
Geoid 4 - fair Highly indirect. Opportunity information from GNSS receiver used for precise orbit determination
Gravity field 5 - marginal Highly indirect. Opportunity information from GNSS receiver used for precise orbit determination
Wind speed (near surface) 4 - fair Over sea only. GNSS receivers on a cluster of micro-satellites. Wind speed estimated from the intensity of signals from different incidence angles, reflected normally