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The Himawari-8 geostationary meteorological satellite managed by the Japan Meteorological Agency (JMA) began operations on 7 July 2015, replacing the previous MTSAT-2 operational satellite. Himawari-8 is leading the way to a new generation of satellite meteorology. Himawari-8 has a new optical payload called the Advanced Himawari Imager (AHI). AHI has 16 radiometric channels in the visible, near-infrared and infrared, from 0.47 m to 13.3 m. Better spectral, spatial, and temporal resolution improves quality and number of critical data products. The instrument will also be flown on GOES-R and COMS-2, with customized changes to radiometric coverage. An independent analysis of the INR processing chain was conducted, which characterizes the geometric error not accounted for by JMAs operational processing. The innovative approach incorporates four stages: (1) landmark measurement generation; (2) estimation of co-registration and spacecraft/instrument attitude; (3) Geometric Error Characterization (GEC) analysis; (4) Verification. Starting with images that have been resampled to a fixed grid, landmark measurements are generated in 10 of the 16 channels (except for WV channels) using a sub-pixel accurate auto-correlation technique. Version 2.0 of the Shuttle Radar Topography Mission Water Body Data was used for the coastline map. Co-registration estimates are derived using the 10.4 m channel as reference and compared with results from JMA. Spacecraft and instrument attitude are estimated, in terms of three Euler parameters, using a simple and intuitive measurement model. Systematic errors were removed from the instrument attitude time series by parsing the errors into repeatable and non-repeatable components. Verification was performed by applying the results of the GEC to the resampling process and the four stages were executed again. Initial findings show that GEC captured an error with a diurnal periodicity and peak-peak magnitude of 14 rad. The source of this error appears to be thermal deformation that is not being compensated for in JMAs INR processing. Its not possible at this time to determine if the error originates within the optics or the AOCS-instrument interface.
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