US 2014/0197984 A1 · VIRTUAL ANTENNA EXTENSION FOR SAMPLED APERTURE ARRAYS

Abstract

A high frequency surface wave radar (HFSWR) system with improved performance. Two or more transmitters including separate transmitting antennas (120, 122, 410) are used to improve the performance of the HFSWR over the performance of a comparable system with a single transmitter. In one embodiment, two transmitters are used, and configured to transmit pulses alternately, with a time interval of at least a round-trip travel time corresponding to a maximum target range between any pair of transmitted pulses. A physical receiving antenna array (130) includes a plurality of receiving antenna elements (135), and is connected to receiver circuitry configured to distinguish returns corresponding to pulses emitted by the different transmitters. The returns are concatenated in the receiver circuitry to achieve improved resolution.

Claims19

Dependent claims

A high frequency surface wave radar system, comprising:

a physical receiving antenna array comprising a plurality of receiving antenna elements;
receiver circuitry coupled to the receiving antenna elements;
a first transmitter, configured to transmit a first sequence of radar pulses separated from each other by at least a round-trip travel time corresponding to a maximum target range;
and
a second transmitter, configured to transmit a second sequence of radar pulses separated from each other by at least the round-trip travel time corresponding to the maximum target range;
wherein the receiver circuitry is configured to:
distinguish first radar returns, corresponding to radar pulses in the first sequence of radar pulses, from second radar returns, corresponding to radar pulses in the second sequence of radar pulses;
and
concatenate the first radar returns and the second radar returns to form a virtual receiving antenna array having a width greater than the width of the physical receiving antenna array.

6 more elements

A method for operating a high frequency surface wave radar system, comprising:

transmitting, from a first transmitting location, a first sequence of first radar pulses, separated from each other by at least a round-trip travel time corresponding to a maximum target range;
transmitting, from a second transmitting location, a second sequence of second radar pulses separated from each other by at least the round-trip travel time corresponding to the maximum target range;
receiving, with a physical receiving antenna array comprising a plurality of receiving antenna elements, a sequence of returns comprising:
first radar returns, corresponding to radar pulses in the first sequence of radar pulses, and
second radar returns, corresponding to radar pulses in the second sequence of radar pulses;
distinguishing the first radar returns from the second radar returns;
and
concatenating the first radar returns and the second radar returns.

5 more elements

Dependencies are inferred from the claim text.

Virtual antenna extension for sampled aperture arrays

Life of this patent

Virtual antenna extension for sampled aperture arrays

Life of this patent

Abstract

Claims19