HR: 12:05h
AN: SF52A-08    [Abstracts]
TI: In Situ Electron Density in Low Earth Orbit From Radio Occultation Data
AU: * Syndergaard, S
EM: ssy@ucar.edu
AF: COSMIC Project Office, University Corporation for Atmospheric Research, P.O. Box 3000, Boulder, CO 80307-3000 United States
AU: Hunt, D C
EM: dhunt@ucar.edu
AF: COSMIC Project Office, University Corporation for Atmospheric Research, P.O. Box 3000, Boulder, CO 80307-3000 United States
AU: Schreiner, W S
EM: schrein@ucar.edu
AF: COSMIC Project Office, University Corporation for Atmospheric Research, P.O. Box 3000, Boulder, CO 80307-3000 United States
AU: Rocken, C
EM: rocken@ucar.edu
AF: COSMIC Project Office, University Corporation for Atmospheric Research, P.O. Box 3000, Boulder, CO 80307-3000 United States
AB: Global Positioning System (GPS) radio occultation data, collected in low earth orbit (LEO), provide valuable information about the vertical structure of electron density in the ionosphere as well as temperature, pressure, and water vapor in the neutral atmosphere. It is well known that profiles of ionospheric electron density can be derived from the observed total electron content (TEC) between the GPS transmitter and the LEO receiver. Recently, we discovered that the data can also provide accurate, model-independent estimates of the electron density at the LEO orbit altitude, provided that the collection of occultation data include the top point where the tangent height is close to the orbit altitude. More precisely, the electron density at the orbit altitude is obtained from the observed TEC data using linear regression of the square of the TEC near the orbit altitude. Thus, the electron density at the LEO at the beginning of an ionospheric occultation can be derived from the occultation data. We are currently applying the approach to GPS occultation data from the Challenging Mini-Satellite Payload (CHAMP), and will present the results of statistical comparisons with in situ electron density measurements from the Planar Langmuir Probe on board CHAMP.
DE: 6934 Ionospheric propagation (2487)
DE: 2467 Plasma temperature and density
DE: 2481 Topside ionosphere
SC: Special Focus: Advances in Data Acquisition, Management, Analysis and Display [SF]
MN: 2004 AGU Fall Meeting