This is the former website for the         OCEAN ALTIMETER PATHFINDER PROGRAM.

As a result of funding decisions made by NASA Headquarters, the Ocean Altimeter Pathfinder program has been terminated.   Previously processed data are available only through the Physical Oceanography DAAC at JPL.   No further data releases or reprocessing of altimeter data will be performed by the Pathfinder team.   Unfortunately, this means that loyal users of Pathfinder altimeter data must find alternative sources for data.

The Pathfinder program, instituted nearly a decade ago by NASA and NOAA, supported the reprocessing of many types of climatological satellite data.  It was realized that climate studies require long time series of measurements of the utmost quality, and that reprocessing of historical data in light of new algorithms and models must play a critical part in generating climate-quality datasets. Many of the former Pathfinder programs are still supported through NASA's REASoN program, but the Ocean Altimeter program is not one of them.

Sea level is normally considered a crucial climate variable.  Satellite altimeter measurements provide the only means to study sea level in a truly global fashion.  Yet constructing a long sea-level record from multiple satellites is a challenging endeavor, since each satellite is susceptible to a range of systematic errors that must be carefully studied and corrected.   This point is currently being driven home by the difficulties arising when merging Jason-1 data with Topex/Poseidon data.  The Jason verification period yielded a unique dataset in which both satellites were measuring the same sea level simultaneously, and yet reconciling these data at the mm/year level is formidable. This fact surely reinforces the need for Pathfinder-type investigations for altimetry.  We encourage an open dialog about this issue at future meetings and NASA Town Halls.

For internal use only

June 2004