apparatus for the navigation system with the loran - c

摘要

LORAN-C navigation apparatus is disclosed wherein digital circuitry and a microprocessor is used to automatically identify LORAN transmitting stations and makes standard hyperbolic navigation measurements. The equipment operator manually enters the group repetition rate into the apparatus for a LORAN-C chain covering the area within which the navigation apparatus is being operated. Initially, the apparatus searches all incoming signals until signals from a master station are received regularly at the stored group repetition rate. The apparatus then closely determines the time of arrival of signals from the secondary stations of the selected LORAN-C chain before changing to a fine search mode in which the exact time of arrival of the secondary station signals is determined; the phase code of the received signals is checked to determine if the received signal is a ground or sky wave, and a determination is made if there is a defective secondary station blink code. The time difference of arrival measurements am then output visually to be plotted in a well known manner on a LORAN-C chart to locate the position of the craft upon which the apparatus is located. IMAGE