00000nam 2200000zi 4500 9.892615 CaOODSP 20221107173223 m o d f cr bn||||||||| 201020s1980 onca ob f000 0 eng d CaOODSP eng rda CaOODSP n-cn--- Co24-3/8-703-1980E-PDF Venier, G. O., author. An investigation of HF direction-finding accuracy on the Frobisher Bay-Ottawa auroral zone path / by G.O. Venier. Ottawa : Communications Research Centre, 1980. 1 online resource (iii, 38 pages) : illustrations. text txt rdacontent computer c rdamedia online resource cr rdacarrier CRC technical note ; no. 703 "Radio and Radar Research Branch." "July 1980." "This work was sponsored by the Department of National Defence, Research and Development Branch under Project No. 33G00." Digitized edition from print [produced by Innovation, Science and Economic Development Canada]. Some pages rotated in this copy. Includes bibliographical references (pages 34-35). "The CRC HF direction-finding array, consisting of a 1181 meter by 236 meter cross, was used to make angle of arrival measurements of waves transmitted over a 2100 km path whose mid point was near the centre of the auroral zone. Swept-frequency transmissions allowed the investigation of the angle variations of individual propagation modes, and fixed-frequency transmissions permitted the measurement of Doppler shifts as well as the sampling of the phase fronts at relatively high rates. E-mode propagation over this path appeared to be entirely of the sporadic variety, but still provided good azimuth accuracy with a median RMS error from the great circle direction around 0.4 degrees for the single-hop case. On the F mode, spreading in range occurred a significant percentage of the time in contrast to experience with lower-latitude paths. This spreading was accompanied by large departures in angle of arrival for this mode from the great circle direction. Two azimuth-estimation techniques were tested on the fixed-frequency data. One used a phase-front planarity test and averaging over relatively frequent samples while the other was based on the separation of modes by Doppler processing. The former technique was found to provide slightly better results than the latter on these data, and its accuracy was, in most cases, close to that which could be obtained from the best mode when separated using swept frequency data"--Abstract, page 1. Issued also in print format. Ionospheric radio wave propagation Measurement. Radio direction finders. Ondes radioélectriques Propagation dans l'ionosphère Mesure. Radiogoniomètres. Communications Research Centre (Canada), issuing body. CRC technical note ; no. 703. (CaOODSP)9.882494 PDF 1.15 MB https://publications.gc.ca/collections/collection_2020/isde-ised/Co24/Co24-3-8-703-1980-eng.pdf