Evaluation Test of an Airborne Loran-C Receiver for Positioning of Flight Experiment Aircraft

Abstract

Evaluation tests of radars and navigation aids often require continuous positioning of the aircraft employed for flight experiments. A Loran-C receiver, JNR-760R, a specially ordered model of JNA-760, was evaluated to see if it can be used for the purpose. Since its accuracy of positioning is most important, calibration test is made by the method of aerial triangulation with the Karl Zeis RMK-21/18 camera, which has a positioning accuracy of the order of 1m.

The JNR-760 R is capable of distance-distance positioning (ρ-ρ navigation) in addition to its normal hyperbolic navigation capability. Test results show superiority of the ρ-ρ method which has an accuracy of about 300 m. This is adequate for evaluation tests of ASR, VOR, etc. However, a sudden turn has caused an error of 800 m. Therefore sudden turns should be avoided when the system is being used for evaluation purposes.