Abstract
NOAA has a long history of using a constellation of two operational GOES satellites to provide the imagery of the Western Hemisphere for the accurate weather forecasting and severe environmental monitoring. As the weather instruments onboard the satellites usually have similar spectral responses, the direct comparison between the infrared (IR) radiance from the overlapped area was used to evaluate the radiance difference between the satellites with high temporal resolution. To date, three of the NOAA’s current generation of geostationary (GEO) satellites, GOES-16/17/18, have been launched since November 2016. GOES-16 has been serving as the GOES-East satellite 75.2oW since December 2017, and GOES-17 was the GOES-West satellite near 137oW, which was recently replaced by GOES-18 on 4 January 2023. The GEO-GEO inter-comparison algorithm was improved for the weather instrument of Advanced Baseline Imager (ABI) onboard the GOES-R satellites with carefully selecting collocation targets. It is implemented to routinely monitor the calibration variation between the ABI IR channels since GOES-17 was in-orbit in 2018. Due to the high temporal resolution and high precision for stability monitoring, this inter-comparison is a powerful tool for detecting operational calibration anomaly in near real time, assisting the anomaly root cause investigations, validating the calibration algorithm updates, and examining the ABI IR radiometric calibration performance at varying temporal scales. The analyses of the diurnal and long-term results show that the ABI IR calibration in general is very stable. Although GOES-17 ABI suffered the Loop-Heat-Pipe (LHP) anomaly, the comparison results between GOES-17 and GOES-16/18 indicate that GOES-17 IR radiometric calibration was stable when the IR focal plane module (FPM) temperature was controlled. The predictive calibration (pCal) algorithm, which was deployed over the floating FPM period for G17 IR bands, greatly improved the radiometric calibration accuracy and thus reduced the diurnal variation for the valid images. Some examples of the GEOGEO inter-comparison to support the operational ABI calibration will also be presented and discussed in the meeting.
Direct Comparison of ABI Infrared Channels on Different GOES
NOAA has a long history of using a constellation of two operational GOES satellites to provide the imagery of the Western Hemisphere for the accurate weather forecasting and severe environmental monitoring. As the weather instruments onboard the satellites usually have similar spectral responses, the direct comparison between the infrared (IR) radiance from the overlapped area was used to evaluate the radiance difference between the satellites with high temporal resolution. To date, three of the NOAA’s current generation of geostationary (GEO) satellites, GOES-16/17/18, have been launched since November 2016. GOES-16 has been serving as the GOES-East satellite 75.2oW since December 2017, and GOES-17 was the GOES-West satellite near 137oW, which was recently replaced by GOES-18 on 4 January 2023. The GEO-GEO inter-comparison algorithm was improved for the weather instrument of Advanced Baseline Imager (ABI) onboard the GOES-R satellites with carefully selecting collocation targets. It is implemented to routinely monitor the calibration variation between the ABI IR channels since GOES-17 was in-orbit in 2018. Due to the high temporal resolution and high precision for stability monitoring, this inter-comparison is a powerful tool for detecting operational calibration anomaly in near real time, assisting the anomaly root cause investigations, validating the calibration algorithm updates, and examining the ABI IR radiometric calibration performance at varying temporal scales. The analyses of the diurnal and long-term results show that the ABI IR calibration in general is very stable. Although GOES-17 ABI suffered the Loop-Heat-Pipe (LHP) anomaly, the comparison results between GOES-17 and GOES-16/18 indicate that GOES-17 IR radiometric calibration was stable when the IR focal plane module (FPM) temperature was controlled. The predictive calibration (pCal) algorithm, which was deployed over the floating FPM period for G17 IR bands, greatly improved the radiometric calibration accuracy and thus reduced the diurnal variation for the valid images. Some examples of the GEOGEO inter-comparison to support the operational ABI calibration will also be presented and discussed in the meeting.