Accession Number:

ADA034420

Title:

A High-Latitude Empirical Model of Scintillation Excursions: Phase I.

Descriptive Note:

Air Force surveys in geophysics,

Corporate Author:

AIR FORCE GEOPHYSICS LAB HANSCOM AFB MASS

Report Date:

1976-09-17

Pagination or Media Count:

56.0

Abstract:

Using observations of the scintillations of beacons from synchronous satellites, a high latitude model of scintillation excursion is being developed. Phase 1 of the development has been completed and is described in this report. Several years of continuous recordings taken at Narssarssuaq, Greenland, Goose Bay, Labrador, and Sagamore Hill, Massachusetts, were reduced. The data base consists of values of 15-min scintillation excursions in dB at 137 MHz. Equations are developed which yield scintillations at this frequency as a function of local time, magnetic index, solar flux, and month of the year. The concept is to predict, at sub-auroral and auroral latitudes, scintillation at this frequency and at higher frequencies. The aim is to give to users an indication of expected scintillation excursion when one predicts magnetic activity and solar radio flux. The equations developed have been checked with one additional set of observations and are being checked with additional data. Phase 2 of this model will incorporate geometrical terms to take account of the propagation angle of the observer vis-a-vis the irregularities and will allow for frequency dependence to be ascertained. In addition, it is expected in Phase 2 to validate the model with additional sets of data, extending the model to auroral latitudes greater than 63 deg. and to polar latitudes. Author

Subject Categories:

  • Atmospheric Physics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE