Tropospheric Refraction Corrections for Airborne Systems.
Abstract
The main objective of this study is to determine the best method for obtaining range error corrections for airborne systems to be used at low elevation angles in Central Europe. It was first necessary to determine whether the atmosphere can be considered horizontally stratified since essentially all techniques for calculating range error are based on that assumption. For four locations having separations ranging from 56 to 240 km, 292 simultaneous refractivity profiles were obtained. Using a numerical integration technique, range errors based on these profiles were computed for each location to an accuracy of + or -0.1m. The corresponding range errors for each location were compared and found to differ by only 2.3%, thus supporting the assumption of a horizontally stratified refractivity model. It was also found that the range errors had essentially no monthly or even seasonal dependence, and that a correction based on an annual mean value which varied only with elevation angle was accurate to 3.6% of the total range error. Finally it was shown that the range error was correlated with surface refractivity and that an accuracy of 3.4% was possible using a linear regression. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 26, 1973
- Accession Number
- AD0913543
Entities
People
- Edward E. Altshuler
- Paul M. Kalaghan
Organizations
- Air Force Cambridge Research Laboratories