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

• Main Author: Sales,G. S.
• Other Authors: ROME AIR DEVELOPMENT CENTER HANSCOM AFB MA ELECTROMAGNETIC SCIENCES DIV
• Format: Text
• Language: English
• Published: 1983
• Subjects: *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; Component Reports; Over the horizon mapping; Greenland Icecap; North Atlantic
• Online Access: http://www.dtic.mil/docs/citations/ADP002726; http://oai.dtic.mil/oai/oai?&verb=getRecord&metadataPrefix=html&identifier=ADP002726

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) This article is from 'Propagation Factors Affecting Remote Sensing by Radio Waves,' AD-A137 559, p11-1-11-12.