Device for compensating a local clock and radio navigation apparatus, in particular of the OMEGA type incorporating the same

Abstract

Abstract 1. Compensation method for a local clock, consisting in : - by means of a reception circuit (2) at least one transmission (F0 , F1 of F2 ) is received in the form of a rectangular signal from at least one transmitter piloted by a high precision clock ; - by means of a synchronization circuit (4) an at least approximate synchronization with the rectangular transmission signals from the transmitter is produced ; - by means of a comparing circuit (1) said transmission is sampled with a sampling frequency (FE ) which is an integral divisor of the frequency (F) of the local clock (3) and a comparison between the frequency of the local clock and that of said transmission is deduced therefrom ; - by means of a correction circuit (5) the frequency of the local clock (3) is corrected as a function of the result of said comparison, the sampling frequency (FE ) being defined in this method by dividing that of the clock and being nominally equal to that of said transmission or to an integer divisor thereof, and wherein a plurality of transmissions of different frequency are received in the form of rectangular signals from at least one transmitter and wherein said sampling frequency (FE ) is an integer common divisor of said transmission frequencies (F0 , F1 , F2 ), characterized in that at the end of the sampling operation pulse couples (a0 , b0 ; a1 , b1 ; a2 , b2 ) are obtained the recurrence of which correspond to said sampling frequency (F) in order to produce a sampling (a0 , a1 , a2 ) and a quadrature sampling (b0 , b1 , b2 ) for a given frequency (F0 , F1 or F2 , respectively), and in that the time shift between said sampling frequency (FE ) and at least one frequency of at least one transmission (F0 , F1 or F2 ) is periodically calculated.

Inventors

• 👤 Michel Collomby
• 👤 Daniel Bec

Bibliographic Details