1. Representing GSICS in other fora: CEOS WGCV & X-CAL
Tim Hewison1
(1) EUMETSAT

2. CEOS WGCV
CEOS WGCV
IVOS group – inter-calibration methodologies, metrology, standards
Microwave group
QA4EO guidelines
Nominate Representatives: To attend IVOS & Microwave group meetings
Special Issue of IEEE Transactions on Geoscience and Remote Sensing on Inter-Calibration of Satellite Instruments
A joint venture between GSICS and IVOS

3. Special Issue of the IEEE TGRS on “Inter-Calibration of Satellite Instruments”
There has been a lot of interest in the community with regards to the special issue topic.
Submission deadline was January 31, 2012
later extended to February 29, 2012
The special issue submissions are now closed.
There was an overwhelming response
close to 45 manuscripts were submitted
Manuscripts undergoing normal review process
Target publication date of March 2013.
The goal of this special journal issue is to capture the state-of-the-art methodologies and results from inter-calibration of satellite instruments
including full end-to-end uncertainty analysis.
Accordingly, this special issue will become a reference anthology for the remote sensing community.

4. GPM X-CAL GPM X-CAL Inter-calibration of microwave instruments
Conical-scanning imagers
Cross-scanning sounders – temperature and humidity channels
Chris Ruf to represent XCAL in the GSICS Microwave Subgroup
Nominate GSICS Representatives: To attend IVOS meetings:
JAXA?

5. GRUAN
The GRUAN network, which provides not only high quality radiosondes but is complemented by high quality ground measurements at each site.
What should the relationship between GSICS and GRUAN be?
Previously on this channel:
Recommendation GRWG06_02 :
GSICS sees GRUAN as an important activity. GRWG sees the primary benefit of GRUAN data to provide validation of GSICS products on Level 2 products in the framework of groups like SCOPE-CM and in the framework of CAL-VAL activities. This will require a 3-way interaction with those groups.
Is this statement still valid?

6. GRUAN Requirements for L2 Product Validation
Time coincidence with Metop flights have to be within 1h:
if there is flexibility timewise: some sondes should be launched on Metop overpasses. This could be restricted to clear-sky days, as assessed by a ground operator
if sondes have to be launched on synoptic times but there is still flexibility in selecting the sites, some could be searched such as to allow could time coincidence with Metop overpass
ideally we need two sondes separated by one hour covering the lower and the upper atmosphere when Metop flies by. This could be restricted and arranged for clear-sky days (assessed by an operator or with whole-sky imager).
The spatial variability can be very high, especially for humidity, such that sondes profiles are not necessarily representative of the area covered by the instrument footprint.
To address this, it is interesting to operate sondes where there is also a ground-based instrument making continuous measurements from which the T,q profiles (or to the first order, the TCWV) can be inferred
e.g. FTIR, microwave or Lidar. I mentioned for instance the FP-7 MUSICA project, dedicated to the water cycle. It involves several ground stations equipped with ground-based FTIRs (
The temporal stability could be used as a criteria to launching a sonde synchronised with Metop fly-by.
The temporal variability can also be extrapolated to the spatial variability if one takes the wind into account.
If not synchronised with Metop overpass, the sondes can be used to calibrate the continuous ground-based retrievals, which are then well collocated timewise with Metop.
We need a site distribution covering land/sea surface and different climate regimes.
Thomas August

7. from the report of the last GCOS AOPC-16 meeting
71. The Panel also raised the potential of radio-occultation measurements to effectively connect the individual radiosonde stations of the GRUAN; in fact radio-occultation measurements on satellites could be considered to be a travelling reference for the upper tropospheric and stratospheric temperatures.
RO comparisons with GRUAN should tell how consistent GRUAN temperature measurements are in the UTLS.

8. Others
Other groups?
Discuss!