2017-03-21 (based on AHI / ABI / AMI) Advanced Next Generation GEO Imagers – Calibration Challenges and Opportunities 2017-03-21 (based on AHI / ABI / AMI)

1st to 2nd Generation From Spinner to 3-Axis Stabilized GOES. Major improvements Increase duty time for ~5% to >80%. Full-optical calibration. Stable Si detectors. Major challenges Dependence of scan mirror emissivity on AOI. Diurnal thermal stress MBCC Seasonal variation of star Banding, striping (related to cal freq).

2nd to 3rd Generation Three times more channels From 5 bands to 16 bands. Four times finer spatial resolution IR (VIS) fom 4 km (1 km) to 2 km (0.5 km) Five times faster scan Full Disk scan from 26 min to 5 min Six times better of data Radiometric requirements SNR for Visible from xxx (TBR) to xxx NEdT for IR from xxxK to xxxK Spectral requirements Narrower by ~half to optimize applications

GOES SRF – RSB

GOES SRF – WV

Major Challenges Hundreds (3 X 4 X 5 X 6) times of performance enhancement Hundreds times of more detectors 1st challenge – Massive arrays of detectors Uniformity – radiometric, imagery (striping) Stitching – ~30 sec time difference Redundancy – hedge against increase complexity 2nd challenge – Coordinate all those detectors New paradigm of INR, from “shoot where pointed” to “point where shot” Kalman filter, Re-sampling 3rd challenge – onboard calibration for VNIR Non-trivial to move to geostationary platform

Some Opportunities Much more GEO-LEO collocations No LEO is wasted. Afford improved match in time and geometry Investigate dependence on Angle Scene radiance Cross-talk Cross calibration for INR Lunar calibration