VOR PROPAGATION AND STABILITY STUDY.
Final rept. Feb 67-Dec 69,
OHIO UNIV ATHENS DEPT OF ELECTRICAL ENGINEERING
Pagination or Media Count:
Results of a theoretical and experimental investigation of propagation effects on VOR course accuracies and stability are presented. Fixed point measurements show propagation errors to be minimal, less than 0.2 degree with a two sigma probability. Effects of VOR receivers, meteorological fronts, tropospheric ducts, vertical polarization, and multipath due to aircraft, on course accuracy are identified and discussed. Evidence gathered from this research clearly indicates that the receiver is the major contributor to indicated course error and when this condition is improved, a factor of five improvement in VOR system accuracy can be available. Thus, the VOR has the potential for providing the increased navigational capability needed for a more dense airway structure for use in an area navigation concept. Special experiments were conducted using conventional and doppler-type VORs as well as a VOT to determine the effect of overflying aircraft on the course information presented in a user aircraft. Results show that the receiver design is critical in determining the magnitude of the perturbation that results. Data from long term, line-of-sight monitoring, accomplished at a range of 40 miles has been reduced and discussions of the identification and classification of significant course errors produced by propagation are provided. Laboratory simulation of propagation and other spurious effects is shown to be one means of aiding in receiver redesign to minimize the receiver response to such signals. Author
- Air Navigation and Guidance