Accession Number : AD0287498

Title :   COMPARISON OF EXPERIMENTAL WITH COMPUTED TROPOSPHERIC REFRACTION.

Corporate Author : NEW MEXICO UNIV ALBUQUERQUE ENGINEERING EXPERIMENT STATION

Personal Author(s) : Anderson ,Wallace L. ; Rainey,Ralph J.

Report Date : OCT 1959

Pagination or Media Count : 22

Abstract : Limits of applicability of ray tracing in computing tropospheric refraction at White Sans Missile Range were explored. A total of 286 comparisons was made, all for a path from radar to fixed beacon of about 45 miles and an elevation angle of 18.32 mils (one mil = 3.2/pi milliradians). A horizontally stratified atmosphere was assumed. Refractive index profiles were prepared from a variety of weather data, and classified A, B, or C in descending order of reliability prior to raytracing calculations for each of the radar readings (165 cases); in 143 cases profiles based only on radiosonde data were aso included for comparison with the A, B, or C results. Angle observations were made with an FPS-16 C-band radar having a quoted instrumental accuracy of 0.14 mils rms. Angle readings varied from 18.70 to 20.92 mils, with mean of 19.37 mils and standard deviation of 0.42 mils. For this experiment it is concluded that most of the rms elevaion angle error is contributed by atmospheric uncertainties. Although ray tracing methods provide a significant correction when sufficiently good weather information is available, there still remains a large uncertainty not accounted for by equipment. (Author)

Descriptors :   *RADAR SIGNALS, EXPERIMENTAL DATA, METEOROLOGY, RANGES (DISTANCE), REFRACTIVE INDEX, TERRAIN, TEST METHODS

Distribution Statement : APPROVED FOR PUBLIC RELEASE