Organization

The GSICS organizational chart given in the Figure also depicts how GSICS fits into the structure of WWW/GOS, whose purpose is to address climate, weather forecasting and other environmental needs of WMO members. GSICS consists of a GSICS Executive Panel, GSICS Coordination Centre (GCC), GSICS Processing and Research Centers (GPRCs), and Calibration Support Segments (CSSs). It also consists of a GSICS Research Working Group (GRWG) and a GSICS Data Working Group (GDWG) that were formed by the WMO.

The GSICS Executive Panel, appointed by WMO, monitors and evaluates the evolution and operations of GSICS. The Panel also provides guidance and advice on the development and enhancement of GSICS. The Panel consists of representatives from WMO and each satellite agency, and conducts annual GSICS progress reviews.

The GCC, located at the NOAA National Environmental Satellite Data and Information Service (NESDIS) facility in Camp Springs, Maryland, U.S., facilitates coordination and communication between the GSICS Executive Panel, GRWG and GDWG Chairs, GPRC Representatives and the CSS entities. It also acts to establish and maintain an important Internet hub of information and data exchange between GSICS members and data users. In addition, the GCC is responsible for publishing the GSICS Quarterly newsletter, and is also active in tracking GSICS progress and milestones, to help GSICS guide its activities.

The GRWG and GDWG coordinate, plan and assist the implementation of GSICS research and data management activities. The GRWG consists of scientists, and the GDWG of data management experts, representing the participating agencies.

A GPRC is located at each operational satellite agency. Each GPRC supports data processing and research activities in the framework of the distributed data and research component of GSICS, which is facilitated by the GDWG, GRWG, and GCC. As GSICS develops, GPRCs are to perform inter-satellite calibration utilizing collocated satellite observations and overlapping satellite records to achieve comparability of sensors on different satellites. GPRCs also intend to collaborate with national standard laboratories of participating countries during pre-launch characterization and calibration activities to ensure that pre-launch calibrations are traceable to the accepted international standards.

A Calibration Support Segment (CSS) represents a GRWG-coordinated research activity carried out by participating satellite agencies, national standards laboratories, numerical weather prediction (NWP) centers, and/or national research laboratories. CSS activities, coordinated by the GRWG, include:

• Performing highly-accurate, SI standards traceable tests on satellite instruments and their on-board calibration references using special satellite and ground-based instruments;
• Championing and supporting "benchmark" missions of the highest accuracy to serve as calibration standards in space;
• Developing calibration “best-practices” procedures;
• Collecting high-quality in-situ data from earth-based reference sites e.g., stable desert areas, long-term specially-equipped ground sites, and intensive field campaigns that are used to monitor satellite instrument performance;
• Independent monitoring of extra-terrestrial calibration sources, such as the sun, moon, and stars, which provide stable calibration targets for on-orbit monitoring of instrument calibration; and
• Simulations of satellite radiances, computed from NWP analyses of atmospheric conditions, which are compared with observations of satellite instruments.

Ultimately, each CSS activity is designed to standardize and improve the accuracy of satellite measurements.