Abstract
A new permanently instrumented radiometric calibration site for high/medium resolution imaging satellite sensors in the visible/near-IR has been set up in Namibia, near the Gobabeb Research and Training Centre on the edge of the Namib Desert. This site is the European contribution to the Committee on Earth Observation Satellites (CEOS) initiative RadCalNet (Radiometric Calibration Network). The Gobabeb area has been selected based on the analysis of different datasets to estimate surface spatial homogeneity, cloud coverage, temporal variability, atmospheric turbidity and flatness.
A field campaign took place in November 2015 in order to find the precise location of the future permanent instrumentation in the area identified from satellite data (Modis, Landsat8, Sentinel2, Pleiades). This location is the one with the best spatial homogeneity at different scales: instrument field-of-view (tens of centimeters), extent of the instrument-monitored area (tens of meters) and satellite sensor resolution (tens to hundreds of meters). The field campaign also focused on the characterization of the surface reflectance, the surface hemispherical directional reflectance factor and the atmospheric turbidity.
Following this campaign, the permanent instrumentation (CIMEL photometer) has been installed in June 2017 and has the ability to measure atmosphere (aerosol optical thickness etc.) and surface conditions (reflectance). The data has been processed by the ROSAS processing software at CNES in order to obtain first results of surface reflectance and to perform the vicarious absolute calibration of optical sensors (Sentinel2A and Sentinel2B, Landsat8 etc.)
The presentation will focus on the installation field campaign and the analysis of the data produced by this new calibration station.
New RadCalNet Instrumented Site at Gobabeb, Namibia: Installation Field Campaign and First Absolute Calibration Results
A new permanently instrumented radiometric calibration site for high/medium resolution imaging satellite sensors in the visible/near-IR has been set up in Namibia, near the Gobabeb Research and Training Centre on the edge of the Namib Desert. This site is the European contribution to the Committee on Earth Observation Satellites (CEOS) initiative RadCalNet (Radiometric Calibration Network). The Gobabeb area has been selected based on the analysis of different datasets to estimate surface spatial homogeneity, cloud coverage, temporal variability, atmospheric turbidity and flatness.
A field campaign took place in November 2015 in order to find the precise location of the future permanent instrumentation in the area identified from satellite data (Modis, Landsat8, Sentinel2, Pleiades). This location is the one with the best spatial homogeneity at different scales: instrument field-of-view (tens of centimeters), extent of the instrument-monitored area (tens of meters) and satellite sensor resolution (tens to hundreds of meters). The field campaign also focused on the characterization of the surface reflectance, the surface hemispherical directional reflectance factor and the atmospheric turbidity.
Following this campaign, the permanent instrumentation (CIMEL photometer) has been installed in June 2017 and has the ability to measure atmosphere (aerosol optical thickness etc.) and surface conditions (reflectance). The data has been processed by the ROSAS processing software at CNES in order to obtain first results of surface reflectance and to perform the vicarious absolute calibration of optical sensors (Sentinel2A and Sentinel2B, Landsat8 etc.)
The presentation will focus on the installation field campaign and the analysis of the data produced by this new calibration station.