Data Processing of GOES-R ABI Special Calibration Scans

The Advanced Baseline Imager (ABI) on board the GOES-R series of satellites features not only an increase in the spatial, spectral, and temporal resolution over the heritage GOES imagers, but also a completely new data collection mechanism in the form of two orthogonal scan mirrors. These mirrors independently sweep ABI’s field of view in the East-West (E-W) and North-South (N-S) directions.

This flexible design allows for collection of non-nominal data for the purposes of calibration and anomaly resolution. Examples include viewing the on-board solar diffuser to update the calibration coefficients for the visible-near infrared (VNIR) channels or acquiring images of the Moon when it is within ABI’s field of view. The most innovative approach to collecting non-nominal data involves fixing the E-W mirror and sweeping the N-S mirror across the Earth. By doing this, ABI will collect a North-South Scan (NSS) where each detector on ABI’s focal plane “sees” a common target on the ground in sequence.

In order to work with this data, the GOES-R ABI Trending and Data Analysis Toolkit (GRATDAT), is being modified to work with NSS. GRATDAT will process NSS data to the point where each detector’s sample is calibrated and navigated, which will allow scientists in the GOES-R Calibration Working Group to compare ABI’s measured radiances to existing satellites (heritage GOES, S-NPP VIIRS, MODIS) or ground truth measurements.

This talk will give an overview of the entire special scan process; a brief description of ABI’s scanning mechanism and its flexibility, a discussion of how these scans are implemented throughout the life of the mission as part of the Mesoscale domain sector request process, and examples of data processed by GRATDAT.