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Instrument details
Acronym
GNSS-RO
Full name
Global Navigation Satellite System - Radio Occultation
Purpose
Temperature/humidity sounding with highest vertical resolution; also space weather
Short description
Measuring the phase delay due to refraction during occultation between GPS and LEO
Background
Consolidated technology
Scanning Technique
Limb scanning from the satellite altitude to close-to-surface by time sampling – Azimuth: 90° sectors fore- and aft-
Resolution
About 300 km horizontal, 0.5 km vertical
Coverage / Cycle
2 GNSS constellations tracked. About 1100 soundings/day - Average spacing 680 km - Global coverage (300 km spacing) in 5 days
Mass
6 kg
Power
50 W
Data Rate
40 kbps
Providing Agency
NASA
Instrument Maturity
Backed by strong heritage
Utilization Period:
TBD
Last update:
2019-01-01
Detailed characteristics
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
future satellites
Instrument classification
Earth observation instrument Active and radio-occultation sensor GNSS radio-occultation
WIGOS Subcomponents
No WIGOS subcomponents have been defined.
Mission objectives
Primary mission objectives Atmospheric temperature Height of the top of PBL Height of the tropopause Specific humidity Temperature of the tropopause
Secondary mission objectives Atmospheric density Electron Density Ionospheric Scintillation Ionospheric Vertical Total Electron Content (VTEC) Opportunity objectives Show all Show fewer
Tentative Evaluation of Measurements
The following list indicates which measurements can typically be
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
Atmospheric temperature 2 - very high Inaccurate in low troposphere. Two directional antennas, two GNSS system tracked, covering about 1000 soundings/day
Geoid 4 - fair Highly indirect. Radio-occultation processing implies precise orbitography. Geoid derived from multi-temporal analysis
Gravity field 5 - marginal Highly indirect. Radio-occultation processing implies precise orbitography. Gravity field derived from multi-temporal analysis
Height of the top of PBL 2 - very high No specific limitation. Two directional antennas, two GNSS system tracked, about 1000 soundings/day. PBL top measured as discontinuity of the refraction index
Height of the tropopause 2 - very high No specific limitation. Two directional antennas, two GNSS system tracked, about 1000 soundings/day. Tropopause height measured as discontinuity of the refraction index
Specific humidity 3 - high Inaccurate in high troposphere. Two directional antennas, two GNSS system tracked, about 1000 soundings/day
Temperature of the tropopause 2 - very high No specific limitation. Two directional antennas, two GNSS system tracked, about 1000 soundings/day
Atmospheric density 1 - primary No specific limitation. Measuring atmospheric density
Electron Density 1 - primary No specific limitation. Two directional antennas, two GNSS system tracked, about 1000 soundings/day
Ionospheric Vertical Total Electron Content (VTEC) 3 - high No specific limitation. Two directional antennas, two GNSS system tracked, about 1000 soundings/day
Ionospheric Scintillation 4 - fair No specific limitation. Two directional antennas, two GNSS system tracked, about 1000 soundings/day
Instrument: GNSS-RO