Validation and Assessment of DMSP Electron Temperatures in the Topside Ionosphere

Geomagnetic disturbances in the near earth space environment can adversely affect numerous military and Department of Defense (DoD) systems and operations. To improve the prediction accuracy of such disturbances, the next generation of space environment forecast models aims to automatically ingest real-time ionospheric measurements. This research validates and assesses one such measurement - the Defense Military Satellite Program (DMSP) measured electron temperature (T(sub e)). DMSP T(sub e), data were validated against near simultaneous incoherent scatter radar (ISR) T(sub e), measurements from Millstone Hill, MA and Sondrestrom, Greenland between Winter 1996 and Summer 2000. Of the 37 Millstone and six Sondrestrom conjunctions compared, DMSP T(sub e), values exceeded ISR T(sub e), values by an average of about 25 percent, which is nearly three times the mean ISR uncertainty. DMSP vs. ISR T(sub e), percent differences were smallest during solar maximum, increasing towards solar minimum, likely due to photoelectron influence on DMSP T(sub e), measurements. In some cases, instrument related anomalies produced unreliable measurements. Based on an assumed linear T(sub e), behavior at mid latitudes, the average DMSP T(sub e) random noise level above Millstone Hill was estimated at about four percent, falling well within the published T(sub e) measurement accuracy. A more comprehensive comparison extending to other sectors of the DMSP orbit is required to further validate the root cause of the DMSP T(sub e), - ISR T(sub e) offset.Air Force Inst of Tech Wright-Patterson AFB OH School of Engineering and Management is the author of 'Validation and Assessment of DMSP Electron Temperatures in the Topside Ionosphere', published 2001 under ISBN 9781423528050 and ISBN 1423528050.