DID YOU KNOW? DTIC has over 3.5 million final reports on DoD funded research, development, test, and evaluation activities available to our registered users. Click
HERE to register or log in.
Accession Number:
ADA172211
Title:
250 MHz/GHz Scintillation Parameters in the Equatorial, Polar and Auroral Environments.
Descriptive Note:
Environmental research papers,
Corporate Author:
EMMANUEL COLL BOSTON MA
Report Date:
1986-03-28
Pagination or Media Count:
36.0
Abstract:
Ionospheric scintillation effects encountered in the equatorial anomaly crest, polar cap and auroral regions have been contrasted to provide information for the design and evaluation of the performance of satellite communication links in ghese regions. The equatorial anomaly region is identified as the most disturbed irregularity environment where the amplitude and phase structures of VHFL-band scintillations are primarily dictated by the strength of scattering rather than ionospheric motion. In the anomaly region, the spectra of intense amplitude scintillations at VHF and L-band are characterized by uniform power spectral density from the lowest frequency 10 MHz to 4 Hz at VHF and to 1 Hz at L-band and steep rolloff at higher fluctuation frequencies with power law indices of -5 to 07. Such structures are compatible with intensity decorrelation times of 0.1 and 0.3 sec at VHF and L-band frequencies, respectively. The phase spectra are described by power law variation of psd with frequency with typical spectral indices of -2. 4. The strong scattering at VHF induces extreme phase rates of 200 deg. in 0.1 sec. The 90th percentile values of rms phase deviation at 250 MHz with 100-sec detrend are found to be 16 rads in the early evening hours whereas amplitude scintillation can cover the entire dynamic range of 30 dB not only at 250 MHz but at L-band as well.
Distribution Statement:
APPROVED FOR PUBLIC RELEASE
