Accession Number:

ADA277355

Title:

Thermospheric Modeling Accuracies Using F10.7 & Ap

Descriptive Note:

Master's thesis

Corporate Author:

NAVAL POSTGRADUATE SCHOOL MONTEREY CA

Personal Author(s):

Report Date:

1993-12-15

Pagination or Media Count:

72.0

Abstract:

This thesis analyzes the accuracy of the 45 day forecasted F10.7 and Ap values given by the Air Force Space Forecast Center. These forecasts are generated daily to aid many agencies in their fields of endeavor. The U.S. Space Command uses the values in orbit prediction routines by way of atmospheric density models. This thesis shows that the F10.7 forecasts are accurate from one to seven days out, then deteriorate for the latter 38 days. Conversely, Ap forecasts are less accurate from one to five days out, then improve beyond the sixth day. The effects of forecasting errors upon satellite lifetimes are then shown using the Lifetime 4.1 orbital propagation model with a Jacchia 71 atmosphere. Propagating a typical satellite for 45 days over various configurations of altitudes and eccentricities showed that only a narrow altitude band from 250km to 325km is affected. Regions above or below this band are not significantly affected with errors in F10.7 or Ap.

Subject Categories:

  • Astronomy
  • Atmospheric Physics
  • Spacecraft Trajectories and Reentry

Distribution Statement:

APPROVED FOR PUBLIC RELEASE