Accession Number : ADP002726

Title :   HF (High Frequency) Over-the-Horizon Mapping of the Greenland Icecap,

Corporate Author : ROME AIR DEVELOPMENT CENTER HANSCOM AFB MA ELECTROMAGNETIC SCIENCES DIV

Personal Author(s) : Sales,G. S.

Report Date : AUG 1983

Pagination or Media Count : 12

Abstract : Continuous observation of the Greenland area using HF over-the-horizon Sounding system in the North Atlantic region has produced a data base for the analysis of backscatter reflectivity at high frequencies (6-30 MHz) from the Greenland Icecap. The proximity of these observations to the auroral region generated the additional complication of excess losses due to D-region absorption. This statistical data base has produced a mapping of th icecap thickness, with backscatter reflectivities that vary from -5 dB to -15 dB below the signals returned from the surrounding sea water. A statistically meaningful daytime absorption of the order of 5 dB was measured over Greenland. At night the significantly increased auroral absorption and atmospheric noise, reduced the system's sensitivity, making mapping impossible. (Author)

Descriptors :   *Over the horizon detection, *Radar mapping, *Radar cross sections, *Atmospherics, *Ice caps, Greenland, D region, Radiation absorption, Sounding, Sea water, Data bases, Doppler radar, Aurorae, Noise, High frequency, Day, Observation, Statistical data, Night, Sensitivity, Thickness, Time, Mapping, Atmospheres, Absorption

Distribution Statement : APPROVED FOR PUBLIC RELEASE