COMPARISON OF EXPERIMENTAL WITH COMPUTED TROPOSPHERIC REFRACTION.

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)

Document Details

Document Type
Technical Report
Publication Date
Oct 01, 1959
Accession Number
AD0287498

Entities

People

  • Ralph J. Rainey
  • Wallace L. Anderson

Organizations

  • University of New Mexico

Tags

DTIC Thesaurus Topics

  • Accuracy
  • Atmospheres
  • C Band
  • Communication Equipment
  • Elevation
  • Errors
  • Observation
  • Radiosondes
  • Ray Tracing
  • Refraction
  • Refractive Index
  • Reliability
  • Standards
  • Uncertainty

Fields of Study

  • Environmental science

Readers

  • Computational Modeling and Simulation
  • Inertial Navigation Systems.
  • Wave Propagation and Nonlinear Chaotic Dynamics.