Method and device for determining a relative alignment of two GPS antennas in relation to one another
AssigneeKathrein-Werke KG
InventorRobert Bieber
Life of this patent
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Abstract
Relative GPS antenna alignment uses a phase shifter electrically connected to a first GPS antenna. A combiner is electrically connected to the phase shifter, the second GPS antenna and to a GPS receiver. A GPS reception signal (Sig1) emitted by the first GPS antenna is phase-shifted by the phase shifter by a phase shift (φ) that can be set by way of a controller and is added by the combiner to a second GPS reception signal (Sig2) emitted by the second GPS antenna. The composite signal (Sum) thus produced is determined for at least three different phase shifts (φ). On the basis of these data, the profile of the composite signal (Sum) and the relative alignment of the two GPS antennas in relation to one another is determined.
Claims25
Method for determining alignment between first and second GPS antennas arranged at a distance from one another, comprising:
- (a) the first GPS antenna receiving at least one GPS satellite signal from a satellite emitting a first GPS received signal, and the second GPS antenna receiving the at least one GPS satellite signal from the satellite emitting a second GPS received signal;
- performing for at least three different phase shifts (φ):
- (b) shifting, using a phase shifter, a phase of the first GPS received signal by a phase shift (φ);
- (c) combining the second GPS received signal with the first GPS received signal which has been phase-shifted by the phase shift (φ), to generate a combination signal;
- (d) using a GPS receiver, generating a sampling signal and/or signal-to-noise-ratio signal from the combination signal, the sampling signal and/or signal-to-noise ratio signal being dependent on the phase shift (φ);
- and
- (e) storing the sampling signal which is dependent on the phase shift (φ) and/or the signal-to-noise-ratio signal which is dependent on the phase shift (φ),
- wherein (b)-(e) are carried out a number (n) of times corresponding to a quotient of a maximum phase shift (φmax) and a phase shift increment (Δφ) for phase shifts (φ) which are integer multiples of the phase shift increment (Δφ), wherein the maximum phase shift (φmax) is at least 360° and the phase shift increment (Δφ) is at most 120°;
- then performing:
- (f) establishing a progression of the sampling signal which is dependent on the phase shift (φ) and/or of the signal-to-noise-ratio signal which is dependent on the Phase shift (φ), the progression being characteristic of the relative positioning of the satellite in relation to the first GPS antenna and the second GPS antenna;
- and
- (g) determining relative alignment of the first GPS antenna in relation to the second GPS antenna on a basis of the progression of the sampling signal and/or the signal-to-noise-ratio signal.
Device for determining a relative alignment of a first GPS antenna in relation to a second GPS antenna each for receiving a GPS satellite signal from a satellite, the second GPS antenna being at the distance from the first GPS antenna, the device comprising:
- a phase shifter which is connected at least indirectly to the first GPS antenna by a first signal line;
- a combiner, which is connected at least indirectly to the phase shifter by the first signal line and to the second GPS antenna by a second signal line;
- a GPS receiver which is electrically connected to the combiner by a third signal line;
- and
- a controller which is connected at least indirectly to the GPS receiver via a fourth signal line and at least indirectly to the phase shifter via a fifth signal line,
- wherein the controller carries out a number (n) of measurements using the phase shifter, the combiner and the GPS receiver, the number (n) corresponding to a quotient of a maximum phase shift (φmax) and a phase shift increment (Δφ) for phase shifts (φ) which are integer multiples of the phase shift increment (Δφ), wherein the measurements measure amplitude patterns relative to phase shift that are characteristic of the relative positioning of the satellite in relation to the first GPS antenna and the second GPS antenna, and the maximum phase shift (φmax) is at least 360° and the phase shift increment (Δφ) is at most 120°.
System for determining relative antenna alignment comprising:
- a first GPS antenna receiving at least one GPS satellite signal from a satellite and providing a first GPS received signal,
- a second GPS antenna receiving the at least one GPS satellite signal from the satellite and providing a second GPS received signal;
- a phase shifting circuit operatively coupled to receive at least one of the provided first and second GPS received signals;
- and
- a controller configured to control the phase shifting circuit to perform for at least three different phase shifts (φ) including:
- (a) shifting a phase of the first GPS received signal by a phase shift (φ);
- (b) combining the second GPS received signal with the first GPS received signal which has been phase-shifted by the phase shift (φ), to generate a combination signal;
- (c) generating a sampling signal and/or signal-to-noise-ratio signal from the combination signal;
- (d) storing the sampling signal which is dependent on the phase shift (φ) and/or the signal-to-noise-ratio signal which is dependent on the phase shift (φ),
- carrying out operations (a)-(d) a number (n) of times corresponding to a quotient of a maximum phase shift (φmax) and a phase shift increment (Δφ) for phase shifts (φ) which are integer multiples of the phase shift increment (Δφ), wherein the maximum phase shift (φmax) is at least 360° and the phase shift increment (Δφ) is at most 120°;
- the controller being further configured to perform:
- (e) establishing a progression of the sampling signal which is dependent on the phase shift (φ) and/or of the signal-to-noise-ratio signal which is dependent on the phase shift (φ), the progression being characteristic of the relative positioning of the satellite in relation to the first GPS antenna and the second GPS antenna;
- and
- (f) determining alignment between the first GPS antenna and the second GPS antenna on a basis of the progression of the sampling signal and/or the signal-to-noise-ratio signal.
Dependencies are inferred from the claim text.