AN HF SWEEP FREQUENCY STUDY OF THE ARCTIC IONOSPHERE

• Main Author: BATES,HOWARD F.
• Other Authors: ALASKA UNIV COLLEGE GEOPHYSICAL INST
• Format: Text
• Language: English
• Published: 1961
• Subjects: *IONOSPHERE; *RADIO WAVES; AURORAE; DENSITY; DIURNAL VARIATIONS; ECHO RANGING; ELECTRONS; HIGH FREQUENCY; IONOSPHERIC PROPAGATION; MAGNETIC PROPERTIES; COMMUNICATION AND RADIO SYSTEMS; REFLECTION; SCATTERING; Arctic; Alaska
• Online Access: http://www.dtic.mil/docs/citations/AD0257534; http://oai.dtic.mil/oai/oai?&verb=getRecord&metadataPrefix=html&identifier=AD0257534

OBSERVATIONS MADE DURING 1958 AND 1959 USING A SWEEP FREQUENCY, HF, oblique sounder located at College, Alaska, are discussed, and selected groups of echoes are illustrated. Groundscatter is the predominant echo type observed on midlatitude backscatter records, but this is not true in the high latitudes. The majority of the scatter echoes from soundings toward geomagnetic north were direct F region scatter of two main types - 1F and constant range echoes. These same echo types were observed from the E region during magnetic disturbances (the slant Es echo corresponds to the 1F echo). These echoes were centered about geomagnetic north on swept azimuth soundings and were produced by scatter near the oblique reflection point in the ionosphere. Thus, the echoes were caused by scatter from irregularities aligned along the geomagnetic field. (Author)