1. Planning comparison study SCM IOGEO and GSICS
8 May 2018 Teleconference
Rob Roebeling, Viju John, Tim Hewison
EUMETSAT

2. on heritage geostationary satellites.
Joint GSICS and IOGEO inter-comparison of reference sensor equivalent WV, IR (and VIS) radiances
Objective
Objective:
IOGEO and GSICS partners to compare reference sensor equivalent (or re-calibrated) radiances from the water vapor (WV), infrared (IR), (and visible (VIS)) channels
on heritage geostationary satellites. 2

3. IOGEO and GSICS inter-comparison - Introduction
Method
To collect re-calibrated data for a common test period:
Channels: WV, IR (and VIS)
Satellites: COMS, GOES, Feng-Yun, Himawari, Kalpana, METEOSAT
Test days: 19 August 2015 and 21 July 2016
Test slots: 3 hourly images (00, 03, 06, 09, 12, 15, 18, 21 GMT)
To encourage IOGEO partners to all use HIRS as reference instrument (Note -> EUMETSAT can provide HIRS record ( ) in standard NetCDF format)
To inter-compare re-calibrated data in overlapping regions (Bias and Spectral Band Adjustment check);
To compare re-calibrated data against IASI observations;
To compare re-calibrated data against simulated radiances from ECMWF (use RTTOV) (use RTTOV, EUMETSTAT did this for their instruments)
Data Exchange
An FTP site has been set up at EUMETSAT where all IOGEO and GSICS partners can upload their test data (details on the next slide)
We started to explore a closer partnership on climate with NOAA aiming at the development of a joint action plan.
However, we are only at the beginning.
Systematic activities: NOAA CDR Program –SAF Network and CAF
Infrastructure Elements:
Analyse reprocessing environments, develop common requirements baseline for reprocessing and search for optimisation of processing;
Increase commonalities on data archiving, data distribution and data post-processing such as, level-3 on demand, sub-setting in time and space, selection of parameters, etc. – develop and share tools;
Analyse potential for further increase of stewardship level by exchanging raw and derived records to have a third copy; also enables improved distribution.
Sensor Intercalibration
Level 2 and Level 3 data Records
CDR Quality Assessment
Interoperability of CDRs.
Benefits of common actions for international activities would be:
GSICS would fulfil the implementation plan items on climate;
SCOPE-CM could be further developed by becoming the international dominant producer of FCDRs;
The latter also strengthens the link between GSICS and SCOPE-CM;
International reanalysis activities will get a one stop shop for FCDRs from operational sensors;
NOAA/EUM can develop a common approach to answer requests from the CEOS WG Climate;
NOAA/EUM activities in GSICS and SCOPE-CM may appear as “the” science support with high visibility in the new WCRP-WDAC and the WCRP-JSC. 3

4. IOGEO and GSICS inter-comparison – FTP site details
Site : ftp.eumetsat.int User accounts : CMA, EUMETSAT, GSICS, IMD, JMA, KMA, NOAA Password : Each user account has a personal password for details mail to Viju John Directories : Each user account has a personal directory with r/w/e permissions Sub Directories : Each personal directory contains the following sub-directories Reference data : IASI and HIRS reference data will be made available on the FTP site Calibrated data : Each user should but their calibrated data in their personal directory
/rse_native
reference sensor equivalent calibrated data original resolution
/rse_resamp
reference sensor equivalent calibrated data re-sampled (5x5 km2)
/aux_native
auxiliary data (e.g. geometry data) original resolution
/aux_resamp
auxiliary data (e.g. geometry data) re-sampled (5x5 km2)
ftp.eumetsat.int
EUMETSAT FTP Administration Account:
Username: iogeo
Password: 8L5ujAs78E
Access rights: Read/Write/Delete
Suppliers: Login name and directory name
1. NOAA
Username: noaa
Password: 3qp3NR5Hwn
Access rights: Read/Write/Delete to content of NOAA directory, read to other suppliers
2. JMA
Username: jma
Password: ccx8EbATA6
Access rights: Read/Write/Delete to content of JMA directory, read to other suppliers
3. CMA
Username: cma
Password: N9f246T5ju
Access rights: Read/Write/Delete to content of CMA directory, read to other
suppliers
4. IMD
Username: imd
Password: qNHFAxwg9v
Access rights: Read/Write/Delete to content of IMD directory, read to other
5. GSICS
Username: gsics
Password: UqHrCc4jkV
Access rights: Read/Write/Delete to content of GSICS directory, read to other
6. TBD
Username: tbd
Password: M4sR8q4Xh3
Access rights: Read/Write/Delete to content of TBD directory, read to other 4

5. IOGEO and GSICS inter-comparison – Status Data Uploads
00z
03z
06z
09z
12z
15z
18z
21z
24z 21
GOES-15
135°W 
GOES-13
75°W
Met-10!
0°E 
Met-7
57°E
Kalpana
82°E 
FY-2D
123°E 
FY-2G
105°E
FY-2F
112°E
COMS-1
128°E
Himawari
145°E
 : GSICS and IOGEO calibrated data ready and uploaded to the common FTP site
 : GSICS calibrated data ready and uploaded to the common FTP site
 : Ready but not yet uploaded to the common FTP site
 : Not ready
 : Current status needs to be checked
! data are not online due to space issue on FTP site

6. Related Recalibration Work @ EUMETSAT
Recalibration HIRS data records (FIDUCEO)
Recalibration MVIRI/SEVIRI IR and WV channels (ERA-CLIM2 and C3S)
Recalibration MVIRI VIS channel (FIDUCEO)
Paper on EUMETSAT GEO recalibration IR/WV is in preparation (John et al., 20??)
Paper on EUMETSAT GEO recalibration VIS is in preparation (Ruethrich et al., 20??)

7. Sensor equivalent calibration
Sensor equivalent calibration [GSICS definition] refers to the calibration where each sensor is calibrated in such a way that the spectral characteristics of that individual sensor are maintained. As a result of this process, the calibrated radiances represent the unique nature (e.g., spectral response function) of the monitored sensor.
Time
Radiances
Sensor 1
Sensor X
Calibration as it should be
Actual Calibration
Note, sensor equivalent calibrations are supposed to differ
in their radiances (or counts) due to differences in
the spectral characteristics of the sensors
NRTC/RAC/ARC
For example, I suggested he discussed with you the "Requirements for NRTC/RAC/ARC". As you know at present we generate Near-Real-Time-Corrections and Re-Analysis Corrections for GEO-LEO IR, based on single pairs of instruments (one monitored, one reference). I would like you to consider what the requirements could be a GSICS Archive Re-Calibration, which is the sort of thing you are doing in SCOPE-CM. E.g. Could these requirements be met by my proposed Prime GSICS Corrections? i.e. Merging together inter-calibration results from different reference instruments, after correcting them to a common datum (the "Primary Reference") using "delta Corrections" (the double-difference of their time series). 7

8. Sensor equivalent calibration (ERA-CLIM2) - IR & WV Meteosat Series -
Figure: Time-series of Meteosat First Generation Sensor Equivalent Calibrated radiances for the Water Vapor Channel (upper panel) and the infrared channel (lower panel)
Courtesy: Marie Doutriaux Boucher, Alessio Lattanzio, Viju John

9. Reference Sensor Normalized Calibration
Reference sensor normalised calibration [GSICS definition] refers to the calibration that provides the best match to spectral characteristics of a predefined “reference*” sensor. As a result of this process, the calibrated radiances represent the unique nature (e.g., spectral response function) of the “reference” sensor. The normalised calibration includes information on uncertainty associated with adjusting the characteristics of the monitored sensor to those of the predefined “reference” sensor.
Sensor 1
Reference Sensor used for normalization
One sensor from a series or
a hypothetical sensor
Sensor X
Radiances
Sensor Equivalent Calibration
Reference Sensor Normalized Calibration
Time
Uncertainty due to differences between
the spectral characteristics of the reference sensor and
the spectral characteristics of other sensors in the series
NRTC/RAC/ARC
For example, I suggested he discussed with you the "Requirements for NRTC/RAC/ARC". As you know at present we generate Near-Real-Time-Corrections and Re-Analysis Corrections for GEO-LEO IR, based on single pairs of instruments (one monitored, one reference). I would like you to consider what the requirements could be a GSICS Archive Re-Calibration, which is the sort of thing you are doing in SCOPE-CM. E.g. Could these requirements be met by my proposed Prime GSICS Corrections? i.e. Merging together inter-calibration results from different reference instruments, after correcting them to a common datum (the "Primary Reference") using "delta Corrections" (the double-difference of their time series). 9

10. Sensor equivalent calibration (ERA-CLIM2) - IR & WV Meteosat Series -
Figure 5: Time-series of Meteosat First Generation Sensor Equivalent Calibrated radiances for the Water Vapor Channel (upper panel) and the infrared channel (lower panel)
Courtesy: Marie Doutriaux Boucher, Alessio Lattanzio, Viju John

11. Reference Sensor Normalized Calibration (ERA-CLIM2) - IR & WV Meteosat Series -
Figure 5: Reference Sensor Normalised time-series of Meteosat First Generation radiances for the Water Vapour Channel (upper panel) and the infrared channel (lower panel)
Courtesy: Marie Doutriaux Boucher, Alessio Lattanzio, Viju John 11

12. Reference Sensor Normalized Calibration (FIDUCEO) - VIS Meteosat Series -

13. Reference Sensor Normalized Calibration (FIDUCEO) - VIS Meteosat Series -
Example of Uncertainty Information that is provided on pixel by pixel basis

14. Reference Sensor Normalized Calibration (FIDUCEO) - VIS Meteosat Series -
ZDM
IODC
Simulation
Recovery
Calibration
Met-2
100%
50%
Met-3 0%
Met-4
Met-5
Met-6
Met-7
Drift of calibration coefficient over desert and ocean using FIDUCEO reconstructed spectral response functions
Drift of calibration coefficient over desert and ocean using pre-launch spectral response function

15. Related Recalibration Work @ JMA
Work of JMA Visiting Scientist Tasuku EUMETSAT in 2017 on: recalibration of IR and WV channels on the JMA GEO satellites using a recalibration method based on GSICS principles that has been applied by EUMETSAT ERA-CLIM2 (for details see presentation Tasuku)
Paper on JMA GEO recalibration is in preparation (Tabata et. al, 20??)

16. Planning Proposal Collaboration GSICS and SCOPE-CM
We started to explore a closer partnership on climate with NOAA aiming at the development of a joint action plan.
However, we are only at the beginning.
Systematic activities: NOAA CDR Program –SAF Network and CAF
Infrastructure Elements:
Analyse reprocessing environments, develop common requirements baseline for reprocessing and search for optimisation of processing;
Increase commonalities on data archiving, data distribution and data post-processing such as, level-3 on demand, sub-setting in time and space, selection of parameters, etc. – develop and share tools;
Analyse potential for further increase of stewardship level by exchanging raw and derived records to have a third copy; also enables improved distribution.
Sensor Intercalibration
Level 2 and Level 3 data Records
CDR Quality Assessment
Interoperability of CDRs.
Benefits of common actions for international activities would be:
GSICS would fulfil the implementation plan items on climate;
SCOPE-CM could be further developed by becoming the international dominant producer of FCDRs;
The latter also strengthens the link between GSICS and SCOPE-CM;
International reanalysis activities will get a one stop shop for FCDRs from operational sensors;
NOAA/EUM can develop a common approach to answer requests from the CEOS WG Climate;
NOAA/EUM activities in GSICS and SCOPE-CM may appear as “the” science support with high visibility in the new WCRP-WDAC and the WCRP-JSC. 16

17. Status
Most data have been collected and are available on the FTP site.
Disk space FTP site needs to be increased to allow uploading of remaining data.
Re-calibrated IR and WV radiances from the GEO satellites from JMA and EUMETSAT are being compared;
Papers on the re-calibration of JMA and EUMETSAT IR and WV radiances are being prepared. 17

18. Planning 2018-2019: recalibration geostationary satellites:
Seek for collaborative activity to perform the GEO-GEO inter-comparison of GSICS (and IOGEO) recalibrated IR, WV, (and VIS) radiances.
Visiting Scientist at EUMETSAT for period of ~one month funded by EUMETSAT?
Post-graduate student project at one of the involved space agencies?
Other suggestions (e.g. VS at other space agency, ..)?
Seek for collaborative activity to accomplish recalibration of all GEO satellites and provide these in a common format:
Visiting Scientist at EUMETSAT for period up to a year based on own funding ? (Similar to JMA VS at EUMETSAT)
Repeat above described work for the visible channels from the GEO satellites
2020: Gridded FCDR (GEO ring) of inter-calibrated radiances
Generate a combined product of gridded inter-calibrated radiances that is based on re-calibrated radiances from as many geostationary satellite data as possible. 18

19. Questions