Title: Transmission of radio navigation phase corrections

Abstract: A method of and apparatus for differential mode navigation in a sequential system of radio-navigation by phase reception. A transmitted amplitude-modulated radio-navigation carrier wave is phase or frequency modulated, this modulation being effected by a low-frequency subcarrier signal which is itself so phase modulated sequentially in accordance with phase corrections that each phase correction appears approximately simultaneously with the phase concerned. The phase corrections are derived from the difference between the phase received from each fixed station of the system and theoretical phases which should be received from that station. At a standard radionavigation receiver, the subcarrier signal modulated by the corrections is recovered, and the phase corrections are so applied to the received phases that each phase undergoes the phase correction received at the same instant.

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Inventors: Nard, Georges (Nantes, FR)

Application Number: 484030
Filing Date: 1974-06-28
Publication_date: 1976-12-14
Assignee: Societe d'Etudes, Recherches et Constructions Electroniques-SERCEL (Carquefou, FR)
Primary Class(es): 342/396
Other Classes:
US Patent Ref:

3715758	Feb, 1973	Sender	343/105.
3774211	Nov, 1973	Nard et al.	343/105.

Other Refs:
Primary Examiner: Wilbur, Maynard R.
Assistant Examiner: Berger, Richard E.
Attorney: Levine; Alan H.