Abstract An installation for the measurement of the distance between a first station and a second station by the duration of a radioelectrical transmission going and returning between the two stations, the first station comprising a transmitter the reception from which at the second station controls a transmission from this latter received in its turn at the first station and compared with the transmission from this latter station, in which the signals transmitted are high frequency signals modulated in phase by a pseudo-code or P-N code, the comparison of the signals received with the signals emitted being obtained by the determination of correlation function values for two phase differences of time, distinct from one another, of the period of the bits of the reference code in accordance with a system known as a ''''delay lock'''' or binary hunting loop, wherein at least at one station the values to be correlated with the signals received are applied to a given circuit path via a commutation switch which alternately connects to the said circuit path one output and another output of the code generator.
In a ranging system of the type in which a first signal is transmitted from a first station to a second station which upon reception thereof transmits a second signal to said first station, each station including a PN code generator for phase modulating said signals and means for correlating the PN generated code with the PN modulated received signal in order to derive at said first station the distance between said two stations by generating the correlations of two successive PN codes spaced apart by one period of the PN code bit sequence and by controlling a delay-lock tracking loop by the difference between said two correlations, the improvement at at least one of said stations comprising, commutation switch means having two inputs connected to said PN code generator and one single output connected to said correlating means, and a commutation switch signal generator operatively connected to said commutation switch means, whereby the PN modulated received signals are successively and alternately correlated with said successive PN codes locally generated at said one station.
Claim 2
Dependent Claim
174 words
In a ranging system of the type in which a first signal is transmitted from a first station to a second station which upon reception thereof transmits a second signal to said first station, each station including a PN code generator for phase modulating said signals and means for correlating the PN generated code with the PN modulated received signal in order to derive at said first station the distance between said two stations by generating the correlations of two successive PN codes spaced apart by one period of the PN code bit sequence and by controlling a delay-lock tracking loop by the difference between said two correlations, the improvement at at least one of said stations comprising, commutation switch means having two inputs connected to said PN code generator and one single output connected to said correlating means, and a commutation switch signal generator operatively connected to said commutation switch means, whereby the PN modulated received signals are successively and alternately correlated with said successive PN codes locally generated at said one station.
Claim 3
Dependent Claim
86 words
The system of claim 1 wherein the improvement further comprises, between said PN code generator and said commutation switch signal generator, a switch controlled by said commutation switch signal generator, the input of said switch being connected to said correlating means and the two outputs of said switch being connected, respectively, to the + input and to the - input of a filter, whereby the single output connectiNg the PN code generator to the correlating means is alloted respectively and successively a + and - sign.
Claim 4
Dependent Claim
30 words
A system according to claim 2 wherein the improvement further comprises a clock controlling the bit sequence of said PN code generator between said filter and said PN code generator.
Claim 5
Dependent Claim
21 words
A system according to claim 2 wherein said improvement further comprises a coherent demodulator between said switch and said correlating means.