Intercalibration of optical satellites - a case study with MOMS and SPOT

The homogeneous test site of La Crau (South of France) was used for radiometric calibration of the MOMS camera onboard the Russian MIR-Station and of the HRV/HRVIR cameras on the SPOT 1 and SPOT 4 satellites. The test site has an extension of approximately 400 m x 400 m and is composed of pebbles which are sparcely covered with dry low vegetation. For the spectral characterization of the test site reflectance measurements with a field spectrometer and a field multichannel radiometer as well as multispectral images from a scanner onboard a low flying aircraft were obtained. To determine atmospheric optical parameters the direct transmission of the atmosphere was measured with sunphotometers and the ground spectrometer simultaneously with the overpass of the space cameras. With the measured reflectances and atmospheric parameters, the Modtran 3.5 [1] radiative transfer code was used to calculate the spectral radiance reaching the space cameras. The paper describes the measuring techniques and discusses the calibration results

Intercalibration of Optical Satellites

The homogeneous test site of La Crau (South of France was used for radiometric calibration of the MOMS camera onboard the Russian MIR-Station and of the HRV/HRVIR cameras on the SPOT1 and SPOT4 satellites. The test site has an extension of approx. 400 m x 400 m and is composed of bare soil and pebbles. For the spectral characterization of the test site reflectance measurements with a field spectrometer and a field multichannel radiometer as well as multispectral images from a scanner onboard a low flying aircraft were obtained. To determine atmospheric optical parameters the direct transmission of the atmosphere was measured with sunphotometers and the ground spectrometer simultaneously with the overpass of the space cameras. With the measured reflectances and atmospheric parameters, the Modtran 3.5 [1] and 6S [10] radiative transfer codes were used to calculate the spectral radiance reaching the space cameras. The paper describes the measuring The homogeneous test site of La Crau (South of France) was used for radiometric calibration of the MOMS camera onboard the Russian MIR-Station and of the HRV/HRVIR cameras on the SPOT1 and SPOT4 satellites. The test site has an extension of approx. 400 m x 400 m and is composed of bare soil and pebbles. For the spectral characterization of the test site reflectance measurements with a field spectrometer and a field multichannel radiometer as well as multispectral images from a scanner onboard a low flying aircraft were obtained. To determine atmospheric optical parameters the direct transmission of the atmosphere was measured with sunphotometers and the ground spectrometer simultaneously with the overpass of the space cameras. With the measured reflectances and atmospheric parameters, the Modtran 3.5 [1]and 6S [10] radiative transfer codes were used to calculate the spectral radiance reaching the space cameras. The paper describes the measuring techniques and discusses the calibration results

Radiometric intercalibration of MOMS and SPOT by vicarious method

The homogeneous test site of La Crau (South of France) was used for radiometric calibration of the MOMS-camera onboard the Russian MIR-Station and of the HRV/HRVIR cameras on the SPOT-01 and SPOT-04 satellites. The test site has an extention of approx. 400 m x 400 m and is composed of bare soil and pebbles. For the spectral characterisation of the test site reflectance measurements with field spectrometers as well as multispectral images with airborne instruments from low flight altitude were obtained. To determine atmospheric optical parameters the ground irradiance of the sun was measured during the time the space cameras passed over the test site. With the measured reflectances and atmospheric parameters the 6S-radiation transfer model was used to calculate the spectral radiance reaching the space cameras. The paper describes the measuring techniques and discusses the calibration results

Vicarious Radiometric Calibration of MOMS at La Crau test site and intercalibration with SPOT

The homogeneous test site of La Crau (South of France) was used for radiometric calibration of the MOMS-2P-camera onboard the Russian MIR-Station and of the HRV cameras on the SPOT satellites. The test site has an extention of approx. 400 m x 400 m and is composed of bare soil and pebbles. For the spectral characterisation of the test site reflectance measurements with field spectrometers as well as multispectral images with airborne instruments from low flight altitude were obtained. To determine atmospheric optical parameters the ground irradiance of the sun was measured during the time the space cameras passed over the test site. With the measured reflectances and atmospheric parameters the 6S-radiation transfer model was used to calcurate the spectral radiance reaching the space cameras. The paper describes the measuring techniques and discusses preliminary calibration results

Radiometric intercalibration of MOMS and SPOT by vicarious method

Communication to : ODAS 2000 - Onera/DLR aerospace symposium, Berlin (Allemagne), June 15-16, 2000SIGLEAvailable from INIST (FR), Document Supply Service, under shelf-number : 22419, issue : a.2000 n.133 / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc

The 2016 CEOS infrared radiometer comparison: Part II: Laboratory comparison of radiation thermometers

To ensure confidence, measurements carried out by imaging radiometers mounted on satellites require robust validation using ‘fiducial quality’ measurements of the same ‘in-situ’ parameter. For surface temperature measurements this is optimally carried out by radiometers measuring radiation emitted in the infrared region of the spectrum, co-located to that of a satellite overpass. For ocean surface temperatures the radiometers are usually on-board ships to sample large areas but for Land and Ice they are typically deployed at defined geographical sites. It is of course critical that the validation measurements and associated instrumentation are internationally consistent and traceable to international standards. The Committee on Earth Observation Satellites (CEOS) facilitates this process and over the last two decades has organised a series of comparisons, initially to develop and share best practise, but now to assess metrological uncertainties and degree of consistency of all the participants. The fourth CEOS comparison of validation instrumentation: blackbodies and infrared radiometers, was held at the National Physical Laboratory (NPL) during June and July 2016 sponsored by the European Space Agency (ESA). The 2016 campaign was completed over a period of three weeks and included not only laboratory based measurements but also representative measurements carried out in field conditions, over land and water. This paper is one of a series and reports the results obtained when radiometers participating in this comparison were used to measure the radiance temperature of the NPL ammonia heat-pipe blackbody during the 2016 comparison activities i.e. an assessment of radiometer performance compared to international standards. This comparison showed that the differences between the participating radiometer readings and the corresponding temperature of the reference blackbody were within the uncertainty of the measurements but there were a few exception, particularly for a reference blackbody temperature of -30 °C. Reasons which give rise to the discrepancies observed at the low blackbody temperatures were identified