Accession Number : AD0753206

Title :   A Comparison of Measured and Calculated VLF Phase Velocities for Day and Night.

Descriptive Note : Technical document Oct 71-Apr 72,

Corporate Author : NAVAL ELECTRONICS LAB CENTER SAN DIEGO CALIF

Personal Author(s) : Westfall,W. D. ; Ferguson,J. A.

Report Date : 20 OCT 1972

Pagination or Media Count : 44

Abstract : Measurements of phase velocity at vlf are made using separated time- and phase-synchronized receivers to obtain phase differentials, and such measurements are compared with theoretical values. Daytime measurements of vlf phase velocity are found to be in good agreement with theoretical values, within the accuracy permitted by the known distance between the receiving sites and an assumed horizontally homogeneous ionospheric model. It is also determined that measured values of phase velocity at night and also at transition times (sunrise and sunset) cannot be effectively compared with theoretical values unless a time-varying ionospheric model is employed. (Author)

Descriptors :   (*RADIO TRANSMISSION, VERY LOW FREQUENCY), SYNCHRONIZATION(ELECTRONICS), PHASE SHIFT CIRCUITS, IONOSPHERIC PROPAGATION, DIURNAL VARIATIONS, PHASE MEASUREMENT

Subject Categories : Radiofrequency Wave Propagation
      Radio Communications

Distribution Statement : APPROVED FOR PUBLIC RELEASE