November 1970 | NTIA Technical Memo OT ITSTM 16

Backscatter studies and 3 D ray tracing final report

James C. Blair

Abstract: Azimuth and spectrum spread was measured from sidescatter and great circle signals over two transmission paths: Washington, D. C. to Boulder, Colorado, and Long Branch, Illinois, to Boulder. Both Doppler and fading spread were measured. The effectiveness of these spread measure­ments in detecting sidescatter to improve the accuracy of DF measurements was determined. The fading component of the complex spectrum was found to provide most of the detection capability. From fading spread measurements, about 75 percent of sidescatter could be detected with 95 percent confidence; from azimuth spread measurements, about 85 percent of sidescatter could be detected with 95 percent probability of success. When both fading and azimuth spread are measured, it appears possible to detect over 95 percent of sidescatter with 95 percent confidence. These conclusions are only good for the Long Branch to Boulder path. The data from the longer path was not taken in large enough quantities to be conclusive.

Disclaimer: Certain commercial equipment, components, and software may be identified in this report to specify adequately the technical aspects of the reported results. In no case does such identification imply recommendation or endorsement by the National Telecommunications and Information Administration, nor does it imply that the equipment or software identified is necessarily the best available for the particular application or uses.

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