GOES-16/ABI Thermal Emissive Bands Assessments using GEO-LEO-GEO Double Difference.

Abstract

Geostationary satellite (GOES)-16/ABI and Himawari-8/AHI represent a significant improvement over the imagers on board previous GOES. Their bands 7-16 are infrared channels covering the 3.9 to 13.3 μm spectral range and with a sub-point spatial resolution of 2 km. Their spectral coverage of the thermal emissive bands (TEB) are almost identical and both instruments employ similar calibration strategies using an on-board blackbody (BB) and a space look. The inter-comparison between the two instruments will be very helpful for their calibration assessments and their product quality enhancements. GOES-16 was launched on November 19, 2016, initially to a test position at 89.5° West and reached its operational position (longitude of 75.2° West) on December 11, 2017. The Himawari-8 spacecraft was launched on October 7, 2014 and the observation focuses on Asia-Pacific region. In this work, an inter-comparison of their TEB measurement is performed using double difference with Aqua MODIS. The same type of scenes are selected for the two instruments and their measurements with the closest observation times are compared with Aqua MODIS matching bands. The view angle effect is corrected and their spectral mismatching effect is estimated. The dependence on the scene uniformity is analyzed. The ABI-AHI differences are within 0.3K for bands 10 (7.35 μm), 11 (8.44 μm), 12 (9.64 μm), and 14 (11.24 μm), and up to 0.8K difference for bands 15 (12.38 μm) and 16 (13.28 μm). The ABI precision is better than AHI for all TEB and their image navigation and registration (INR) precisions are comparable. In general, the ABI performance before and after re-location is consistent.