The Defense Meteorological Satellite Program (DMSP) provides global visible,
infrared, and passive microwave data as well as other specialized meteorological,
oceanographic, and solar-geophysical data in support of worldwide Department
of Defense (DoD), Department of Commerce (DoC), and National Aeronautics and
Space Administration (NASA) operations. The DMSP F17 satellite,
launched in November 2006, is in a near-circular, sun-synchronous, polar orbit.
This document provides an overview of the DMSP mission, the F17 satellite,
and a brief overview of the ground data system. Separate platform description
documents are available for the F8, F10, F11,
and F15 satellites.
Defense Meteorological Satellite Program (DMSP) Block 5D-3 Satellite F17, DMSP F17
DMSP, originally known as the Defense System Applications Program (DSAP) and the Defense Acquisition and Processing Program (DAPP), is a long-term satellite program designed to monitor the meteorological, oceanographic, and solar-geophysical environment of the Earth in support of DoD operations. The United States Air Force (USAF) has maintained an operational constellation of two near-polar, sun-synchronous satellites for military purposes since the first launches of Block 1 DMSP satellites in 1962. In December 1972, DMSP data were declassified and made available to the civil and scientific communities.
All spacecraft launched have had a tactical (direct readout) and a strategic (stored data) capacity. DMSP-5D3 is the most recent version of the military meteorological satellites of the Defense Meteorological Satellite Program with F15, the predecessor to F17, as the first satellite of the DMSP-5D3 series. Unlike F17, DMSP F15 is technically considered a hybrid platform as it is outfitted with the new DMSP-5D3 spacecraft bus and the DMSP-5D2 suite of sensors. F17 incorporates a new suite of sensors on the Block 5D3 spacecraft bus.
Under a 1994 Presidential directive, a tri-agency organization between the DoD, DoC, and NASA was formed in order to converge the parallel polar-orbiting weather satellite programs of the DoD and DoC--the DMSP and Polar Orbiting Environmental Satellite (POES) programs, respectively. The goal of this tri-agency effort is the development of a National Polar Orbiting Environmental Satellite System (NPOESS) that will ultimately meet the needs of all three agencies. Funding for DMSP continues to be provided by the DoD and USAF.
As part of the NPOESS convergence effort, the DoC assumed control of DMSP satellites from the USAF in 1998. Satellite command is provided by a joint-operational team at the U.S. Department of Commerce's National Oceanic and Atmospheric Administration (NOAA) control center in Suitland, Maryland. DMSP data are also distributed through NOAA to the civilian and scientific communities. The USAF Space Systems Division at Los Angeles Air Force Base in Los Angeles, California continues to be responsible for the development and acquisition of DMSP systems.
The DMSP mission is to provide global visible, infrared, and passive microwave data as well as other specialized meteorological, oceanographic, and solar-geophysical data in support of worldwide DoD, DoC, and NASA operations.
The DMSP F17 satellite was built by General Electric's Astro-Space Division (now part of Northrop Grumman/Lockheed Martin). It was launched on 04 November 2006 from Vandenberg AFB, California using a Boeing Delta IV rocket. The spacecraft is approximately 4 meters in length with an on-orbit mass of 825 kilograms.
The DMSP F17 satellite is among the first of a new suite of weather satellites built by Lockheed Martin Missiles & Space. Improvements include a new spacecraft structure, two additional panels on the solar array for more power, an additional battery, more computer memory, improved computer software, and two solid-state recorders replacing older reel-to-reel tape recorders used in previous DMSPs.
The DMSP F17 satellite is in a near-circular, sun-synchronous, polar orbit. Additional details of the platform are as follows:
Pointing accuracy: 0.01 degree (primary), 0.12 degree (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. Operation 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.
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:
Data are then relayed at 3.072 Mbps via commercial geostationary communications satellite to Air Force Global Weather Central (AFGWC) and the Fleet Numerical Meteorology and Oceanography Center (FNMOC). Spacecraft commanding is done at L-band at a 2 Kbps rate.
The following Block 5D-3 sensors are on board the DMSP F17 platform:
DMSP satellite command and control is performed by the 6th Satellite Operations Group at Offutt AFB, Nebraska.
Data are transmitted in real time to tactical terminals worldwide. Data are also stored using onboard recorders for transmission to and processing by AFGWC at Offutt AFB, Nebraska and by the FNMOC in Monterey, California. Both AFGWC and FNMOC relay the SSMIS 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):
Delaney, T. 2007. "Northrop Grumman Successfully Checks Out Sensors on New Air Force Weather Satellite." Northrop Grumman. http://www.irconnect.com/noc/press/pages/news_releases.html?d=113400 [February 2009].
Dubach L., and C. Ng. 1988. NSSDC's Compendium of Meteorological Space
Programs, Satellites, and Experiments, March 1988.
Kramer, H.J. 2002. Observation of the Earth and Its Environment: Survey of Missions and Sensors, 4th Edition, Springer-Verlag, ISBN: 3540423885, May 2002.
Strom, S. R. and G. Iwanaga. 2005. "Overview and History of the Defense Meteorological Satellite Program," Crosslink, The Aerospace Corporation magazine of advances in aerospace technology, Vol. 6, No 1, 2005.
Sweetman, B. 2006. Jane's Space Directory 2006/2007, Jane's
Information Group, ISBN: 071062767X, June 2006.
OLS: The Operational Linescan System. OLS measures visible (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.
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.
SSJ/5: Precipitating Plasma Monitor. The SSJ/5 measures the transfer energy, mass, and momentum through the magnetosphere-ionosphere in the Earth's magnetic field. The SSJ/5 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.
SSM: Special Sensor Magnetometer. The SSM, a triaxial fluxgate magnetometer, measures geomagnetic fluctuations associated with geophysical phenomena.
SSMIS: Special Sensor Microwave Imager/Sounder. The SSMIS sensor is a conically-scanning passive microwave radiometer that harnesses the imaging and sounding capabilities of three previous DMSP microwave sensors, including the SSMI, the SSM/T-1 temperature sounder, and the SSMI/T-2 moisture sounder. The SSMIS sensor measures microwave energy at 24 frequencies from 19 to 183 GHz with a swath width of 1700 km.
Table 1 lists acronyms and abbreviations used in this document.
|AFB||Air Force Base|
|AFGWC||Air Force Global Weather Central|
|DMSP||Defense Meteorological Satellite Program|
|DoC||Department of Commerce|
|DoD||Department of Defense|
|DSAP||Defense System Applications Program|
|DAPP||Defense Acquisition and Processing Program|
|FNMOC||United States Navy Fleet Numerical and Oceanography Center|
|kbps||Kilobits Per Second|
|Mbps||Megabits Per Second|
|NESDIS||National Environmental Satellite Data and Information Service|
|NGDC||National Geophysical Data Center|
|NOAA||National Oceanic and Atmospheric Administration|
|NSSDC||National Space Science Data Center|
|OLS||Operational Linescan System|
|SSIES||Special Sensor Ionospheric Plasma Drift/Scintillation Meter|
|SSJ/5||Special Sensor Precipitating Plasma Monitor|
|SSM||Special Sensor Magnetometer|
|SSM/I||Special Sensor Microwave Imager|
|SSMIS||Special Sensor Microwave Imager/Sounder|
|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|
Document Creation Date: February 2009
Document ID: DMSP F-17 Platform Document
Document Curators: NSIDC Writers
Document URL: http://nsidc.org/data/docs/daac/f17_platform.gd.html