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GES DISC DAAC Data Guide:
Defense Meteorological Satellite Program (DMSP) Satellite F12 Source/Platform
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THIS DOCUMENT IS AVAILABLE ON THE GES DISC WEB SITE FOR HISTORICAL INFORMATION
PURPOSES ONLY.
Information provided in this document may not be accurate. We recommend
checking other sources related to these data or sensors to acquire reliable and
updated information.
Explanation: The Dataset or Sensor Guide Document you are accessing is no longer actively
maintained. The Dataset Guide Documents were created for earlier versions of
the NASA EOSDIS system. The content of these documents, particularly with
regard to characteristics of the data or technical descriptions of a sensor, is
likely still accurate. However, information such as contact names, phone
numbers, mailing addresses, email addresses, software programs, system
requirements, and data access procedures may no longer be accurate. We
therefore recommend searching for updated information from other sites to
insure that reliable and current information is obtained.
Summary:
This document contains information about the DMSP F12 Satellite. The DMSP F12 satellite
is a in a near circular, sun synchronous, polar orbit. The DMSP mission is to provide global
visible and infrared cloud data and other specialized
meteorological, oceanographic and solar-geophysical data in support of world wide Department
of Defense (DoD) operations. A description of the mission is provided as
is information about the spacecraft and its environment. The ground data system
is briefly described.
Table of Contents:
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- Defense Meteorological Satellite Program (DMSP) Block 5D-2 Satellite F12, DMSP F12
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- DMSP, originally known as the Defense System Applications Program
(DSAP) and the Defense Acquistion and Processing Program (DAPP), is a long-term
USAF effort in space to monitor the meteorological, oceanographic and solar-geophysical
environment of the Earth in support of DoD operations. All spacecraft launched have
had a tactical (direct readout) and a strategic (stored data) capacity. In December
1972, DMSP data was declassificed and made available to the civil/scientific community.
The USAF maintains an operational constellation of two near-polar, sun-synchronous satellites
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- Satellite
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- The DMSP program office is located at the Space Systems Division, Air Force Material
Command, Los Angeles Air Force Station, Los Angeles, California 90009-2960. Funding is
provided by the Department of Defense (DoD).
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- The DMSP mission is to provide global visible and infrared cloud data and other specialized
meteorological, oceanographic and solar-geophysical data in support of world wide Department
of Defense (DoD) operations.
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- DMSP Satellite F12 was built by General Electric's Astro-Space Division (now part of Martin
Marietta Astro Space). It was launched on August 29, 1994 from Vandenberg AFB,
California using an Atlas E rocket. The spacecraft is 3.7 meters in length with a diameter of
1.2 meters with an on-orbit mass of 831 kilograms. It has a design lifetime of 48 months.
Power is provided though a 9.29 sq-m solar cell panel. Attitude is controlled using momentum
wheels and magnetic coils using a strap-down star sensor and gyros as the reference.
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- DMSP Satellite F12 is in a near circular, sun synchronous, polar orbit.
- Maximum Altitude: 851 km
- Minimum Altitude: 844 km
- Inclination: 98.9 deg
- Period: 102.0 minutes
- Eccentricity: 0.00123
- Ascending Equator Crossing Time (Local Time):
- At Launch: 21:22
- Current (09/02/95): 21:27
- Swath Width:
- Visible and Infrared Imagery - 3000 km
- Microwave Imagery - 1400 km
- Temperature Sounder - 1500 km
- Water Vapor Profiler - 1500 km
- Launch Date - August 29, 1994
- End Mission (Operational Support - F12 is currently (9/2/95) providing primary support with
sensors OLS, SSM/T, SSM/T-2, SSJ/4, SSIES2, SSM and SSB/X-2 still providing data.
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- Pointing Accuracy: 0.01 deg (primary), 0.12 deg (backup)
- Stability: maximum rate - 0.03 deg/sec per axis.
Short term changes in attitude are measured using three orthogonal gyroscopes. A strap down
star sensor is used to bound the effects of gyroscope drift. The desired attitude is computed
based upon a star catalog and an ephemeris table uplinked to the spacecraft daily. Three-axis
attitude control is maintained in the orbital configuration by automatic momentum exchange
between three momentum wheels. Onboard magnetic coils provide controlled interaction with
the earth's magnetic field to prevent the accumulation of wheel secular momentum. Operations
of these coils is under control of the closed loop spacecraft attitude control system. Both the
momentum wheels and gyroscopes are backed up by a fourth skewed unit for redundancy.
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- Data is transmitted in real time to tactical terminals world-wide. Data is also stored using on-board
recorders for transmission to and processing by the Air Force Global Weather Central
(AFGWC), Offutt AFB, Nebraska and the Fleet Numerical Meteorology and Oceanography
Center (FNMOC), Monterey, California. Both AFGWC and FNMOC relay the SSM/I, SSM/T and SSM/T2 data to the
National Environmental Satellite, Data, and Information System (NESDIS). AFGWC also sends
the entire data stream to the National Geophysical Data Center (NGDC).
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- DMSP uses S-band links at 1.024 Mbps for the tactical real time transmissions. Stored data are
transmitted at 2.66 Mbps to receiving sites at
- Fairchild AFB, Washington
- Thule, Greenland
- AF Remote Tracking Station, Hawaii and the
- New Hampshire Tracking Station
Data are then relayed at 3.072 Mbps via commercial geostationary communications satellite to AFGWC
and FNMOC. Spacecraft commanding is done at L-band at a 2 Kbps rate.
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- DMSP satellite command and control is performed by the 6th Satellite Operations Group at
Offutt AFB, Nebraska.
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- Data is transmitted in real time to tactical terminals world-wide. Data is also stored using on-board
recorders for transmission to and processing by the Air Force Global Weather Central
(AFGWC), Offutt AFB, Nebraska and the Fleet Numerical Meteorology and Oceanography
Center (FNMOC), Monterey, California. Both AFGWC and FNMOC relay the SSM/I, SSM/T and SSM/T2 data to the
National Environmental Satellite, Data, and Information System (NESDIS). AFGWC also sends
the entire data stream to the National Geophysical Data Center (NGDC).
-
- Ascending Equatorial Crossing Time (Local Time):
- At Launch: 21:22
- Current (09/02/95): 21:27
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- L. Dubach, C. Ng, NSSDC's Compendium of Meteorlogical Space Programs, Satellites, and Experiements,
March 1988.
- H.J. Kramer, Observation of the Earth and its Environment - Survey of Misions and Sensors, 2nd Edition,
Springer-Verlag, ISBN: 3-540-578587, May 1994.
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- OLS - The Operational Linescan System (OLS) measures visbile (0.4-1.1 micrometers) and infrared
(10.25-12.6 micrometers) wavelengths to provide day and night cloud cover imagery. The satellite measures
data at a 0.56 km resolution, which is averaged on board, to produce global coverage at 2.7 km resolution.
All of the 2.7 km resolution (smooth) data is downlinked to the ground sites while a small amount of the
0.56 km resolution (fine) data is stored and downlinked. The OLS is the primary sensor on each DMSP
satellite.
- SSM/I
- Special Sensor Microwave Imager
- SSM/T-1 - Special Sensor Microwave Temperature Sounder. The SSM/T is a seven channel, cross track nadir scanning passive microwave
sounder having a field of view of 14.4 degrees. It measures the Earth surface and atmospheric emmission in the 50 to 60 GHz oxygen band.
At nominal altitute, the subtrack spatial
resolution is an circle of 174 km at nadir and an ellipse of 213x304 km toward the limb. There are seven total
cross-track scan positions seperated by 12 degrees at frequencies 50.5, 53.2, 54.35, 54.9, 58.4, 58.825 and 59.4 GHZ.
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SSM/T-2 - Special Sensor Microwave Water Vapor Profiler
- SSJ/4 - Precipitating Plasma Monitor. The SSJ/4 measures the transfer energy, mass, and momenturm through
the magnetosphere-ionosphere in the Earth's magnetic field. The SSJ/4 sensor consists of four electrostatic
analyzers that record the flux of precipitating ions or electrons at 20 fixed energy channels between 50 eV and
30 keV.
- SSIES - Special Sensor Ionspheric Plasma Drift/Scintillation Meter. The SSIES measures the ambient electron
density and temperatures, ambient ion density, the average ion temperature and molecular weight, the plasma drift
and scintillation at the DMSP orbital altitude.
- SSBX-2 - Gamma Ray Particle Detector. The SSB/X-2 is an array-based system which detects the location,
intensity, and spectrum of X-rays emitted from the Earth's atmosphere.
- SSM - Special Sensor Magnetometer. The SSM, a triaxial fluxgate magnetometer, measures geomagnetic fluctuations
associated with geophysical phenomena.
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See the EOSDIS Glossary for a more
general listing of terms related to the Earth Observing System
project.
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- AFB -
Air Force Base
- AFGWC -
Air Force Global Weather Central
- DMSP -
Defense Meteorological Satellite Program
- DoD -
Department of Defense
- FNMOC -
United States Navy Fleet Numerical and Oceanography Center
- NESDIS -
National Environmental Satellite, Data, and Information Service
- NGDC -
National Geophysical Data Center
- OLS -
Operational Linescan System
- SSBX-2 -
Special Sensor Gamma Ray Particle Detector
- SSIES -
Special Sensor Ionospheric Plasma Drift/Scintillation Meter
- SSJ/4 -
Special Sensor Precipitating Plasma Monitor
- SSM -
Special Sensor Magnetometer
- SSM/I -
Special Sensor Microwave Imager
- SSM/T-1 -
Special Sensor Microwave Temperature Sounder
- SSM/T-2 -
Special Sensor Microwave Water Vapor Profiler
- USAF -
United States Air Force
- URL -
Uniform Resource Locator
-
See the EOSDIS Acronyms for a more
general listing of terms related to the Earth Observing System
project.
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Change History
- Version 1.0
- Version baselined on addition to the GES Controlled Documents List, September 19, 1995.
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Atmos Composition
