RESULTS OF PRELIMINARY FLIGHT EVALUATIONS COMPARING THE PERFORMANCE OF H-FIELD AND E-FIELD LORAN-C ANTENNAS IN THE PRESENCE OF PRECIPITATION STATIC

摘要

The susceptibility of Loran-C receivers tornprecipitation static has been a significantrncontributor in preventing full utilization of Loran-rnC for aircraft navigation. Precipitation static is arnbuild-up of electric charge on the aircraft whichrnoccurs while flying in precipitation. Typicallyrnoccurring while flying in light rain or snow, thisrnbuild-up of electric charge on the aircraft degradesrnthe signal-to-noise ratios (SNR) of the receivedrnLoran-C signals. This results in decreasedrnpositional accuracy and may even result in arncomplete loss of Loran-C navigation information.rnThe data presented in this paper were attained tornshow the improvement factors associated withrnusing a H-field versus an E-field Loran-C antennarnin a high precipitation static environment.rnIncluded are descriptions of the test aircraft, Loran-rnC receivers, and antennas used for the testing.rnInstances of flights encountering precipitationrnstatic are presented. These flights show that thernSNR?s from the receiver using the E-field antennarnwere significantly degraded while those using thernH-field antenna were essentially unaffected.