Accession Number:

ADA025714

Title:

Tropospheric Effects on Signals at Very Low Elevation Angles

Descriptive Note:

Technical memo.

Corporate Author:

JOHNS HOPKINS UNIV LAUREL MD APPLIED PHYSICS LAB

Personal Author(s):

Report Date:

1976-03-01

Pagination or Media Count:

42.0

Abstract:

Two possible sources of error in computing a tropospheric range correction from a model are mismatch between the model and the actual refractivity profile, and neglect of a signal path bending. To study the error sources, the tropospheric range effect on a radio signal has been evaluated at different elevation angles, for some observed atmospheres, by three methods a using meteorological balloon data, the effect is evaluated along the computed, curved signal path this is our best estimate of the true effect and is the standard for comparison b using meteorological balloon data, the effect is evaluated for assumed straight-line propagation and c using only surface meteorological data, the effect is evaluated from the two-quartic tropospheric model for assumed straight-line propagation. The differences b - a and c - b, respectively, represent the path-bending component and the profile-mismatch component of the total model error c - a. Results are presented in figures. The effect of the model-based correction on the computation of tracking-station position is shown for a few sample cases.

Subject Categories:

  • Radiofrequency Wave Propagation
  • Unmanned Spacecraft
  • Radio Communications

Distribution Statement:

APPROVED FOR PUBLIC RELEASE