○Radiometric calibration

The vicarious calibration techniques achieve to determine the radiometric spectral level and the sensor degradation.
This website focuses on the high spectral resolution GHGs sensors (such as GOSAT, OCO-2, TRPOMI, OCO-3, and GOSAT-2) radiometric calibration in Railroad Valley Desert Playa, NV, USA.

○Vicarious calibration campaign

We have conducted an annual joint calibration and validation (calval) campaign in Railroad Valley from 2009.
This website provides a long term campaign data of surface reflectance, radio sonde, and airplane GHG data.

Railroad Valley (RRV)
Base-camp: 38.49703 N; 115.69013W
Height : about 1435m

Railroad Valley site feature

  • Reflectance greater than 0.3 to reduce the impact of atmospheric uncertainty
  • Spatially uniform to minimize mis-registration effects
  • Minimal seasonal variations in surface reflectance
  • Large spatial extent of test site for large footprint sensors
  • An arid region to reduce the probability of clouds and reflectance variations from changing surface moisture
  • Nearly lambertian with flat topography to simplify bi-directional reflectance characterization and reduce uncertainty from surface bidirectional effects
  • Spectrally flat surface reflectance to simplify band-to-band comparisons within sensors and across sensors

≪Past campaign for other satellite≫

Campaign Data

○Surface reflectance (in-situ)

NASA JPL : Surface reflectance measured by ASD field spectrometer.

Data Link

○Temperature and Humidity profile (radio sonde)

JAXA : Temperature and Humidity profile measured with radio sonde.

Data Link

○Trace gas profile

NASA Ames : Alpha Jet Atmospheric eXperiment (AJAX)

Data Link

○CO2 and CH4 total column density (EM27/SUN)

JAXA: CO2 and CH4 total column density measured with ground-based portable FTS (EM27/SUN)

Data Link