Accession Number:

ADA464850

Title:

Holes: Ionospheric Scintillation, GPS and Imputation

Descriptive Note:

Master's thesis

Corporate Author:

AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH SCHOOL OF ENGINEERING AND MANAGEMENT/DEPT OF ENGINEERING PHYSICS

Personal Author(s):

Report Date:

2007-03-01

Pagination or Media Count:

102.0

Abstract:

Ionospheric scintillation of Global Positioning System GPS signals threatens navigation and military operations by degrading performance or making GPS unavailable. Scintillation is particularly active, although not limited to, a belt encircling the earth within - 20 degrees of the geomagnetic equator. This belt also hosted roughly half of the completed U.S. military operations in the last decade. The authors examined scintillation data from Ascension Island, United Kingdom, and Ancon, Peru, in the Atlantic longitudinal sector as well as data from Parepare, Indonesia, and Marak Parak, Malaysia, in the Pacific longitudinal sector. From these data, they calculate percent probability of occurrence of scintillation at various intensities described by the Ssub 4 index. In addition, they determine Horizontal Dilution of Precision HDOP at one minute resolution examine diurnal, seasonal, and solar cycle characteristics and compare latitudinal and longitudinal data. Their findings are consistent with previous research, but unlike previous research they attempt to replace, or impute, missing Ssub 4 values to better capture the extent of scintillation. In doing so, they study data gaps, or holes, and characterize them. The scheme results in an increase in the observed fraction of scintillated satellites.

Subject Categories:

  • Atmospheric Physics
  • Radiofrequency Wave Propagation
  • Statistics and Probability

Distribution Statement:

APPROVED FOR PUBLIC RELEASE