BackForwardInstrument:  YunYao-receiver 

Instrument details
Acronym YunYao-receiver
Full name YunYao GNSS receiver
Purpose Temperature/humidity/ionospheric sounding for meteorology and space weather. Also measures surface parameters through reflected signal.
Short description

Measuring the phase delay due to refraction during occultation between GPS and LEO. Utilises Beidou, GPS, Glonass and Galileo constellations.
Background

New development
Scanning Technique

Limb scanning from 400 km to close-to-surface by time sampling - Azimuth: 90°
Resolution Atmospheric profiles about 200 km horizontal, <0.5 km vertical Ionospheric profiles <4 km vertical for TEC and electron density
Coverage / Cycle Depends on how many GNSS satellites in constellation. 150,000 profiles/day by 2025 and 60,000 ionospheric profiles. Time resolution of 12-20 mins.
Mass Power Data Rate

 

Providing Agency CASIC
Instrument Maturity Backed by strong heritage
Utilization Period: 2024 to 2030
Last update: 2024-02-26
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
  • Subcomponent 4
  • GNSS radio occultation (commercial)
  • GNSS radio occultation constellation (commercial)
Mission objectives
Primary mission objectives
  • Atmospheric density
  • Atmospheric temperature
  • Electron Density
  • Height of the tropopause
  • Ionospheric Total Electron Content (TEC)
  • Specific humidity
  • Wind speed (near surface)
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
Note: * Primary mission objective.
VariableRelevance for measuring this variableOperational limitationsExplanation
Atmospheric temperature*3 - highInaccurate in low troposphere.One directional antenna, one GNSS system tracked, covering about 250 soundings/day
Geoid4 - fairHighly indirect.Radio-occultation processing implies precise orbitography. Geoid derived from multi-temporal analysis
Gravity field5 - marginalHighly indirect.Radio-occultation processing implies precise orbitography. Gravity field derived from multi-temporal analysis
Height of the top of PBL3 - highNo specific limitation.One directional antenna, one GNSS system tracked, about 250 soundings/day. PBL top measured as discontinuity of the refraction index
Height of the tropopause*3 - highNo specific limitation.One directional antenna, one GNSS system tracked, about 250 soundings/day. Tropopause height measured as discontinuity of the refraction index
Precipitation intensity at surface (liquid or solid)5 - marginalHeavy precipitation onlyPrecipitation detected by de-polarisation measurement (experimental)
Specific humidity*3 - highInaccurate in high troposphere.One directional antenna, one GNSS system tracked, about 250 soundings/day
Temperature of the tropopause3 - highNo specific limitation.One directional antenna, one GNSS system tracked, about 250 soundings/day
Wind speed (near surface)*5 - marginalOver sea only.. Infrequent coverage.Wind speed estimated from the intensity of signals from different incidence angles
Atmospheric density*1 - primaryNo specific limitation.Measuring atmospheric density
Electron Density*1 - primaryNo specific limitation.One directional antenna, one GNSS system tracked, about 250 soundings/day
Ionospheric Total Electron Content (TEC)*3 - highNo specific limitation.One directional antenna, one GNSS system tracked, about 250 soundings/day
Ionospheric Scintillation4 - fairNo specific limitation.One directional antenna, one GNSS system tracked, about 250 soundings/day