BackForwardInstrument:  GOLPE 

Instrument details
Acronym GOLPE
Full name GPS Occultation and Passive reflection Experiment
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 (adaptation of the NASA/JPL BlackJack)
Scanning Technique Limb scanning from the satellite altitude to close-to-surface by time sampling. Azimuth: 70° sectors, aft- and fore-
Resolution About 300 km horizontal, 0.5 km vertical
Coverage / Cycle 1 GNSS constellation tracked. About 500 soundings/day - Average spacing 1000 km - Global coverage (300 km spacing) in 10 days
Mass 3.2 kg Power 15 W Data Rate 17 kbps

 

Providing Agency NASA
Instrument Maturity Flown on an R&D satellite
Utilization Period: 2001 to 2013-08-15
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
Mission objectives
Primary mission objectives
  • Atmospheric temperature
  • Height of the top of PBL
  • Height of the tropopause
  • Specific humidity
  • Temperature of the tropopause
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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
VariableRelevance for measuring this variableOperational limitationsExplanation
Atmospheric temperature3 - highInaccurate in low troposphere.Two directional antennas, one GNSS system tracked, covering about 500 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.Two directional antennas, one GNSS system tracked, about 500 soundings/day. PBL top measured as discontinuity of the refraction index
Height of the tropopause3 - highNo specific limitation.Two directional antennas, one GNSS system tracked, about 500 soundings/day. Tropopause height measured as discontinuity of the refraction index
Specific humidity3 - highInaccurate in high troposphere.Two directional antennas, one GNSS system tracked, about 500 soundings/day
Temperature of the tropopause3 - highNo specific limitation.Two directional antennas, one GNSS system tracked, about 500 soundings/day
Atmospheric density1 - primaryNo specific limitation.Measuring atmospheric density
Electron Density1 - primaryNo specific limitation.Two directional antennas, one GNSS system tracked, about 500 soundings/day
Ionospheric Vertical Total Electron Content (VTEC)3 - highNo specific limitation.Two directional antennas, one GNSS system tracked, about 500 soundings/day
Ionospheric Scintillation4 - fairNo specific limitation.Two directional antennas, one GNSS system tracked, about 500 soundings/day