SUMMARY
OF
CHANGES OF iSHAI VERSION 2018.1 WITH RESPECT TO PREVIOUS
VERSION iSHAI VERSION 2016
GEO-iSHAI algorithm remains based in Jun Li’s algorithm for GOES
Sounder physical retrieval algorithm (physical iterative approach
with non-linear regression as first guess) but adapted for RTTOV and
other GEO imager instruments. Jun Li (CIMSS-Wisconsin) algorithm is
also the one proposed as Day-1 algorithm for the GOES-R processing
by NOAA (Li, 2010).
GEO-iSHAI release 2025 has some major updates due to the
introduction of the support of MTG-I/FCI. In version 2025 MSG,
Himawari and GOES-R class satellites are also supported.
The use of RTTOV-13 in version 2025 implies that the number of RTTOV
pressure levels remains in 54 RTTOV pressure levels.
All the coefficients has been calculated using the GEO-iSHAI
validation dataset for 2017 year with vertical dimensions adjusted
to the used RTTOV pressure levels.
A summary of the changes of iSHAI version 2018 with respect to
previous version 2016 is available here.
A summary of the changes of iSHAI version 2016 with respect to
previous version former PGE13 SPhR version 2013 is available here.