Evaluation of the Performance of the Remote Area Precision Positioning System (RAPPS)

摘要

A flight test program was flown within the coverage area of the West Coast Loran-C chain during June and July 1979. These tests were conducted for Loran-C evaluation purposes. The Remote Area Precision Positioning System (RAPPS) was utilized as the data collector and independent positioning system for those tests. This report presents an evaluation of the performance of the RAPPS system under actual test conditions. The RAPPS positioning system is based on DME multilateration and takes advantage of existing TACAN or DME installations. It was found under certain conditions to suffer degradation due to multipath propagation and signal dropouts due to terrain masking. After isolating clearly erroneous measurements, residual ranging errors of 285 ft (1 sigma) were estimated based on available data. The RAPPS data collector was designed to acquire data from two Loran-C receivers, the DME subsystem, an altimeter and a clock. The data collector functioned satisfactorily with a few deficiencies. The foremost deficiency was a lack of precise time-tagging of each individual data element, which caused processing of the Loran-C data to be quite difficult. (Author)