Transmission signal direction finding apparatus and method
First Claim
1. A method for determining the direction of origin of a received transmission signal using the phase differences provided by receiving the signal with a spinning pair of antennas, comprising the steps of:
- measuring the phase difference between the signals received simultaneously by a spinning antenna pair for a single transmission signal, at a predetermined number of approximately evenly spaced angular positions within a revolution of the spinning antenna pair;
coarsely approximating the direction of origin of the transmission signal based upon the measured phase differences;
calculating a first phase difference signal based upon the coarsely approximated direction;
reconstructing a phase difference signal using the phase differences measured from the antenna pair and the calculated phase difference signal;
determining the first time derivatives of the reconstructed phase signal and the calculated phase signal;
correcting the reconstructed phase signal in response to a comparison between the first derivatives of the reconstructed phase signal and the calculated phase signal;
finely determining the direction of origin of the transmission signal based upon the corrected reconstructed phase signal.
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Accused Products
Abstract
An apparatus and method for determining the direction of origin of a received transmission signal using a spinning antenna pair generally provides the steps and apparatus for measuring the phase difference between signals simultaneously received, coarsely approximating the direction of origin of the transmission signal, reconstructing a phase difference signal using the measured phase differences and a calculated signal based upon the coarse approximation, correcting the reconstructed phase signal based upon the first derivatives of the reconstructed signal and the calculated signal, and determining the direction of origin based upon the corrected reconstructed phase signal.
23 Citations
15 Claims
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1. A method for determining the direction of origin of a received transmission signal using the phase differences provided by receiving the signal with a spinning pair of antennas, comprising the steps of:
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measuring the phase difference between the signals received simultaneously by a spinning antenna pair for a single transmission signal, at a predetermined number of approximately evenly spaced angular positions within a revolution of the spinning antenna pair; coarsely approximating the direction of origin of the transmission signal based upon the measured phase differences; calculating a first phase difference signal based upon the coarsely approximated direction; reconstructing a phase difference signal using the phase differences measured from the antenna pair and the calculated phase difference signal; determining the first time derivatives of the reconstructed phase signal and the calculated phase signal; correcting the reconstructed phase signal in response to a comparison between the first derivatives of the reconstructed phase signal and the calculated phase signal; finely determining the direction of origin of the transmission signal based upon the corrected reconstructed phase signal. - View Dependent Claims (2, 3, 4, 5, 6, 12, 13)
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7. An apparatus for determining the direction of origin of a transmission signal, comprising:
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means for receiving a transmission signal with a spinning antenna pair; means for measuring the phase difference between signals received simultaneously by the antenna pair at a predetermined number of approximately evenly spaced angular positions within a revolution of the spinning antenna pair; means for coarsely approximating the direction of origin of the transmission signal; means for calculating a first phase difference signal based upon the approximated direction; means for reconstructing a phase difference signal using the phase differences measured from the antenna pair and the first calculated first phase difference signal; means for determining the first time derivatives of the reconstructed phase signal and the calculated first phase signal; means for correcting the reconstructed phase signal in response to a comparison between the first derivatives of the reconstructed phase signal and the calculated first phase signal; and means for finely determining the direction of origin of the transmission signal based upon the corrected reconstructed phase signal. - View Dependent Claims (8, 9, 10)
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11. An apparatus for determining the direction of origin of a transmission signal, comprising:
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means for receiving a transmission signal with a spinning antenna pair; means for simultaneously sampling signals received by the antenna pair; and programmed computational means coupled to receive the sampled signals and including instructional means for; measuring the phase difference between the signals received simultaneously by a spinning antenna pair for a single transmission signal, at a predetermined number of approximately evenly spaced angular positions within a revolution of the spinning antenna pair; coarsely approximating the direction of origin of the transmission signal based upon the measured phase differences; calculating a first phase difference signal based upon the coarsely approximated direction; reconstructing a phase difference signal using the phase differences measured from the antenna pair and the calculated phase difference signal; determining the first time derivatives of the reconstructed phase signal and the calculated phase signal; correcting the reconstructed phase signal in response to a comparison between the first derivatives of the reconstructed phase signal and the calculated phase signal; and finely determining the direction of origin of the transmission signal based upon the corrected reconstructed phase signal. - View Dependent Claims (14, 15)
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Specification