Frequency diversity pulse pair determination for mitigation of radar range-doppler ambiguity
AssigneeThe United States of America as represented by the Administrator of the National Aeronautics and Space Administration
InventorsLIHUA LI, MATTHEW MCLINDEN, MICHAEL COON, GERALD HEYMSFIELD, VIJAY Subbaraman Venkatesh
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Abstract
The disclosed subject matter relates to Frequency Diversity Pulse Pair (FDPP) methods and technology implemented by, alternating the order of the pulse pair transmitted or order of the group of multiple pulses transmitted, the pulses differentiated based on the center frequency of each transmitted pulse. For example, where a pair of transmitted pulses have center frequencies f1 and f2, the pulses transmitted in pairs such that the first pair may be f1 followed by f2 and the second pair are a different order, such as f2 followed by f1.
Claims20
A method for operating a radar system, comprising:
- a. transmitting at least two pairs of pulses, each pair including center frequencies f1 and f2 and such that the order the pulses f1 and f2 are transmitted is reversed every alternate pair transmission;
- b. receiving a corresponding reflection signal as a reception signal after the at least two pairs of pulses are reflected by a point scatterer;
- and
- c. determining the mean radial velocity vr of the point scatterer from a transmitted waveform and received signal of frequency f1 followed by a transmitted waveform and a received signal of frequency f2 in a first pulse pair and a transmitted waveform and received signal of frequency f2 followed by a transmitted waveform and a received signal of frequency f1 in a second pulse pair where the first and second pulse pairs are transmitted in succession.
A method for operating a radar system, comprising:
- a. transmitting at least two pairs of pulses, each pair including center frequencies f1 and f2 and such that the order the pulses f1 and f2 are transmitted is reversed every alternate pair transmission;
- b. receiving a corresponding reflection signal as a reception signal after the at least two pairs of pulses are reflected by a point scatterer;
- and
- c. determining the mean radial velocity vr where vr=cΔΦ/(4π(f1+f2), c is the speed of light, ΔΦ=ΔΦorder1+ΔΦorder2, and ΔΦorder1 and ΔΦorder2 are determined using pulse pair algorithm and measurements obtained by f1/f2 and f2/f1 pulse pairs as ΔΦorder1=arg(ERx,f1(t)E*Rx,f2(t+ΔT)), and ΔΦorder2=arg(ERx,f2(t)E*Rx,f1(t+ΔT)).
A radar system, comprising:
- a. a transceiver configured to generate at least two pairs of pulses, each pair including center frequencies f1 and f2 and such that the order the pulses f1 and f2 are transmitted is reversed every alternate pair transmission;
- b. a radar antenna connected to the transceiver to (1) receive from the transceiver and transmit the at least two pairs of pulses and (2) receive and transmit to the transceiver a corresponding reflection signal after the at least two pairs of pulses are reflected by a point scatterer;
- and
- c. a digital receiver/processor connected to the transceiver to receive the reflection signals and configured to determine the mean radial velocity vr of the point scatterer from a transmitted waveform and received signal of frequency f1 followed by a transmitted waveform and a received signal of frequency f2 in a first pulse pair and a transmitted waveform and received signal of frequency f2 followed by a transmitted waveform and a received signal of frequency f1 in a second pulse pair where the first and second pulse pairs are transmitted in succession.
Dependencies are inferred from the claim text.