GES DISC DAAC Data Guide:
Geostationary Meteorological Satellite Platform Document

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Summary:

Table of Contents:

• 1 Source/Platform or Data Collection Environment Overview
• 2 Ground Segment Information
• 3 References
• 4 Glossary of Terms
• 5 List of Acronyms
• 6 Document Information

1. Source/Platform or Data Collection Environment Overview:

Source/Platform or Data Collection Environment Long Name, Source/Platform Acronym:

Geostationary Meteorological Satellite, GMS

Source/Platform Introduction:

The first GMS was launched from the United States on July 14, 1977. The GMS-2 GMS-3, GMS-4, and GMS-5 were launched by Japanese rockets in August 1981, August 1984, and September, 1984, 1994, respectively. The spacecraft consists of a spinning section which rotates at 100 rmp and an antenna assembly that is Earth-oriented which provides for high gain communications with ground stations. The spinning section carries the VISSR and supporting subsystems.

Collection Environment:

Satellite.

Source/Platform Program Management:

The GMS are operated by Japan's National Space Development Agency (NASDA) and Japan's Meteorological Agency (JMA).

Source/Platform Mission Objectives:

There are four major objectives for the GMS program:

1. Provide data for the World Meteorological Organization's World Weather Watch Progam,
2. Collect meteorological observation data,
3. Disseminate of digital image data and processed analog image data,
4. Monitor solar particles.

Source/Platform Parameters:

The first GMS was launched from the United States on July 14, 1977. The GMS-2 GMS-3, GMS-4, GMS-5 were launched by Japanese rockets in August 1981, August 1984, and September, 1984, 1994 respectively. GMS are 2.1 m in diameter and 4.4 m in height with a separated weight of 680.9 kg. The GMS are in a stationary orbit 22,300 miles above the equator positioned at 140 degrees East longitude.

Coverage Information:

The GMS program monitors weather across Japan and the eastern Pacific from stationary orbit 22,300 miles above the equator at 140 degrees East longitude. A complete 20 degree by 20 degree scan of the full Earth disk can be produced every half hour.

Attitude Characteristics:

This information is not available at this time.

Data Collection System:

The GMS communications system consist of primary and redundant units which can be switched on or off by ground commands, except for the Unified S-Band (USB) receivers, which are always on. The communications system provides the following:

• S-Band transmission of VISSR signals to Command and Data Acquisition Stations (CDAS),
• S-Band relay of image data from CDAS to user stations,
• S-Band relay of trilateration ranging signals to or from the CDAS to two Turn Around Ranging Stations,
• S-Band transmission of telemetry signals to and reception from the CDAS and the Tracking and Control Stations (TACS),
• S-Band to UHF relay of Data Collection Platforms interrogation signals from CDAS to DCP,
• UHF to S-Band relay of report signals from DCP to CDAS,
• Unified S-Band tracking, telemetry, and command capability as the primary link during transfer orbit and as backup during synchronous orbit.

Communication Links:

This information is not available at this time.

List of Sensors/Instruments:

The primary instrument aboard GMS is the Visible and Infrared Spin Scan Radiometer (VISSR). The VISSR provides visible and infrared images of the Earth and it's cloud cover through the use of an optical telescope and detector system.

2. Ground Segment Information:

Tracking and Control:

This information is not available at this time.

Data Acquisition and Processing:

The primary ground station facilities include the Command and Data Acquisition Stations (CDAS), the Data Processing Center (DPC), and the Tracking and Control Center (TACC). The roles of the ground station facilities is provided below.

1. The CDAS transmits spacecraft operation commands. The CDAS receives observed image data and meteorological data from the DPC and telemetry data from the spacecraft.

2. DPC is the central processing unit for the GMS system. A computer system there performs:

• Image data processing to produce facsimile chart and meteorological parameters
• Trasmission of products generated
• Operation and control of the satellite.

3. The TACC provides housekeeping and station keeping operations as well as serving as the backup for the Meteorological Satellite Center.

Latitude Crossing Times:

This information is not applicable for this platform.

3. References:

Rao, P.K., S.J. Holmes, R.K. Anderson, J.S. Winston, and P.E. Lehr: 1990: Weather Satellites: Systems, Data, and Environmental Applications, American Meteorological Society, Boston, MA, 503 pp.

A.R. Curtis, 1994: Space Satellite Handbook, Gulf Publishing, Houston, TX, 346 pp.

4. Glossary of Terms:

See the EOSDIS Glossary for a more general listing of terms related to the Earth Observing System project.

5. List of Acronyms:

See the EOSDIS Acronyms for a more general listing of terms related to the Earth Observing System project.

• CDAS - Command and Data Acquisition Stations

• DPC - Data Processing Center

• GMS - Geostationary Meteorological Satellite

• NASDA - National Space Development Agency

• JMA - Japan's Meteorological Agency

• TACC - Tracking and Control Center

• URL - Uniform Resource Locator

• VISSR - Visible and Infrared Spin Scan Radiometer

6. Document Information:

Document Revision Date:Fri May 10 11:52:24 EDT 2002

July 31, 1996

Document Review Date:

July 31, 1996

Document ID:

This information is not available at this time.

Change History

Version 2.0

Version baselined on addition to the GES Controlled Documents List, July 31, 1996.