Monitoring the Stability of the DSCOVR EPIC Sensor's Visible Channels using MODIS and VIIRS as a Reference
Abstract
The Earth Polychromatic Imaging Camera (EPIC) instrument aboard the Deep Space Climate Observatory (DSCOVR) satellite has a constant unique view of the sunlit disk of the Earth from the Lagrange-1 (L1) point nearly a million miles away from the Earth. The EPIC sensor has ten spectral channels ranging through the UV, VIS, and NIR light spectrums. Since EPIC has no on-board calibration systems, EPIC's ten spectral channels must be inter-calibrated using on-orbit methods, such as inter-calibration with the Aqua-MODIS and SNPP-VIIRS radiometers. The EPIC instrument is inter-calibrated with both MODIS and VIIRS using ray-matched radiance pairs over both deep convective cloud (DCC) and all-sky tropical ocean (ATO) targets. Spectral band adjustment factors (SBAFs) are applied in order to mitigate spectrally induced radiance differences. The EPIC version 2 dataset included many improvements such as stray-light correction, flat-fielding, and improved geolocation, and the quality of these improvements will be evaluated. The newly released EPIC version 3 has greatly improved the residual navigation error found in version 2, thus reducing the calibration uncertainty of this method. These MODIS and VIIRS based EPIC calibration coefficients should improve the quality of the EPIC based cloud/aerosol/land use retrievals so that they can be combined with retrievals from the constellation of Earth orbiting imagers.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2019
- Bibcode:
- 2019AGUFM.A43L2983H
- Keywords:
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- 3311 Clouds and aerosols;
- ATMOSPHERIC PROCESSES;
- 3359 Radiative processes;
- ATMOSPHERIC PROCESSES;
- 3360 Remote sensing;
- ATMOSPHERIC PROCESSES