PRECIPITATION EFFECTS ON OMEGA AIRCRAFT RECEIVERS.
Abstract
Omega is a very-low-frequency (vlf) radio navigation system characterized by very long range and an accuracy on the order of 1 to 2 mi with respect to earth coordinates. Early flight tests of Omega aircraft receivers using vertical electric-field antennas achieved excellent results in good weather but experienced almost constant signal loss in precipitation conditions. Signal losses appeared to be caused by precipitation static and shorting of the insulation at the bases of the antennas. Modifications of vertical antennas, including shielding of the leading edge and improved base insulators, reduced but did not solve the problem. An experimental NRL-designed-and-constructed crossed-loop antenna system improved reception characteristics with respect to both wetting and static pickup. NRL has evaluated the performance of modified vertical antennas and crossed-loop antennas in the laboratory and on Omega test flights. These flight tests have revealed that the crossed-loop antenna offers adequate sensitivity and a significant reduction of precipitation effects and thus provides all-weather operation of Omega aircraft receivers. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- May 18, 1970
- Accession Number
- AD0707710
Entities
People
- R. L. Eisenberg
Organizations
- United States Naval Research Laboratory