Accession Number:

ADA224392

Title:

An Assessment of the Application of in situ Ion-Density Data from DMSP to Modeling of Transionospheric Scintillation

Descriptive Note:

Final rept. 15 Sep 1989-14 Mar 1990

Corporate Author:

NORTHWEST RESEARCH ASSOCIATES INC BELLEVUE WA

Report Date:

1990-03-15

Pagination or Media Count:

34.0

Abstract:

Modern military communication, navigation, and surveillance systems depend on reliable, noise-free transionospheric radio-frequency channels. They can be severely impacted by small-scale electron-density irregularities in the ionosphere, which cause both phase and amplitude scintillation. Basic tools used in planning and mitigation schemes are climatological in nature and thus may greatly over- and under-estimate the effects of scintillation in a given scenario. This report summarizes the results of a three-year investigation into the feasibility of using in-situ observations of the ionosphere from the USAF DMSP satellite to calculate estimates of irregularity parameters that could be used to update scintillation models in near real-time. Estimates for the level of intensity and phase scintillation on a transionospheric UHF radio link in the early-evening auroral zone were calculated from DMSP Scintillation Meter SM data and compared to the levels actually observed. The intensity scintillation levels predicted and observed compared quite well, but the comparison with the phase scintillation data was complicated by low-frequency phase noise on the UHF radio link. Results are presented from analysis of DMSP SSIES data collected near Kwajalein Island in conjunction with a propagation-effects experiment. Preliminary conclusions to the assessment study are 1 the DMSP SM data can be used to make quantitative estimates of the level of scintillation at auroral latitudes, and 2 it may be possible to use the data as a qualitative indicator of scintillation-activity levels at equatorial latitudes. Keywords Ionosphere, Ionospheric scintillation, Radiowave scintillation. JHD

Subject Categories:

  • Atmospheric Physics
  • Radiofrequency Wave Propagation

Distribution Statement:

APPROVED FOR PUBLIC RELEASE