The Defense Meteorological Satellite Program (DMSP) satellites currently in orbit are designated the Block SD-2 series.
Characterized by on-board processing and near full redundancy, the Block 5D-2 design provides a stable, highly reliable
platform for a sophisticated sensor suite. Under both solar and lunar illumination conditions, the payload instruments
provide visual radiances with very high dynamic range, as well as calibrated radiances in the infrared and microwave
spectral regimes. Additional space environmental sensors provide in-situ measurements of electrons and ions, energy
distribution of charged particles, and changes in the local magnetic field. The DMSP mission sensor digital data is now
available from the National Geophysical Data Center in Boulder, Colorado. The future 5D-3 spacecraft, currently in
production, will be a larger structure with increased power and weight capability to accommodate a greater payload,
including a combined microwave sensor providing imaging and temperature and moisture profiling in one instrument.
New space environmental instruments observing in the ultraviolet spectrum will improve specification ofthe ionosphere.
On 5 May 1994, the U.S. President directed convergence ofthe Department ofDefense (DOD) DMSP system and the
Department of Commerce (DOC) National Oceanic and Atmospheric Administration's (NOAA) Polar-orbiting Operational
Environmental Satellite (POES). The Integrated Program Office (IPO) was formed to implement the merger and develop a
single system, the National Polar-orbiting Operational Environmental Satellite System (NPOESS), to provide data for U.S.
civil and defense as well as international needs. Negotiations between NOAA and EUMETSAT are underway for an
interim Joint Polar System (JPS). This is proposed to be a two-satellite constellation in which one satellite is POES and
one is from EUMETSAT. In the timeframe ofNPOESS, it is anticipated that continued cooperation with EUMETSAT
will lead to a three-satellite JPS constellation, in which two are NPOESS and one is from EUMETSAT.