Accession Number:

AD0716774

Title:

Tropospheric Effect on Electromagnetically Measured Range: Prediction from Surface Weather Data.

Descriptive Note:

Technical memo.,

Corporate Author:

JOHNS HOPKINS UNIV SILVER SPRING MD APPLIED PHYSICS LAB

Personal Author(s):

Report Date:

1970-07-01

Pagination or Media Count:

41.0

Abstract:

The height integral of tropospheric refractivity n-1, where n is refractive index, measures the range error in a vertically arriving electromagnetic signal. Such height integrals were studied, using meteorological balloon data from widely separated locations. Although the dry part of n-1 at any point in the troposphere depends on both pressure and temperature PT, its height integral was found to be a linear function of surface pressure only, both theoretically and from observed data. The equivalent height for the quartic model of n-1dry must therefore vary as surface temperature. Height parameters were computed from balloon data and were closely the same for all stations a dry height of 40.1 km at 0C, decreasing to zero near 0K. Using these, the model predicts vertical range error dry part within a few millimeters rms. Study of the very much smaller but more variable wet contribution is continuing. Author

Subject Categories:

  • Atmospheric Physics
  • Radiofrequency Wave Propagation

Distribution Statement:

APPROVED FOR PUBLIC RELEASE