Radar apparatus and methods for determining the presence of a reflective target using a multiple response comparison

1 . A method of processing radar responses of a radar system characterized by a plurality of beam patterns, to determine if a given response corresponds to a reflective object, each beam pattern disposed in a different azimuthal direction, the method comprising:

for a first beam pattern of the plurality of beam patterns, identifying a first response at an identified angle relative to a center of the first beam pattern;

calculating an anticipated response for a second beam pattern of the plurality of beam patterns, the second beam pattern overlapping the first beam pattern, the anticipated response representing the response expected in the second beam pattern if the first response corresponds to a reflective object; and

determining that the first response corresponds to a reflective object if a measured response in the second beam pattern at an angle relative to the center of the second beam pattern that corresponds to the identified angle relative to the center of the first beam pattern is within a predetermined error threshold of the anticipated response, wherein the anticipated response includes an anticipated sum beam response and an anticipated delta beam response, the predetermined error threshold comprises a quality of match metric including terms based on deviation of a sum beam response of the second beam pattern from the anticipated sum beam response and deviation of a delta beam response of the second beam pattern from the anticipated delta beam response.

2 . The method of claim 1 wherein, for a third beam pattern of the plurality of beam patterns that overlaps the first beam pattern, determining if a measured response in the third beam pattern at an angle relative to the center of the third beam pattern that corresponds to the identified angle relative to the center of the first beam pattern is within a second predetermined error threshold of a second anticipated response, the second anticipated response representing the response expected in the third beam pattern if the first response corresponds to a reflective object.

3 . The method of claim 2 , wherein the predetermined error threshold is equal to the second predetermined error threshold.

4 . The method of claim 1 , wherein the first beam pattern and the second beam pattern are adjacent beam patterns.

5 . The method of claim 1 , further comprising, before the step of identifying a response at an identified angle relative to a center of the first beam pattern, measuring a response at an angle relative to a center of an initial beam pattern, and

for each of a lagging beam of the initial beam pattern and a leading beam pattern of the initial beam pattern, determining the greatest magnitude of

1) The response of the initial beam pattern,

2) The measured response in lagging beam pattern at an angle relative to the center of the lagging beam pattern that corresponds to the identified angle relative to the center of the initial beam pattern, and

3) The measured response in leading beam at an angle relative to the center of the leading beam pattern that corresponds to the identified angle relative to the center of the initial beam pattern, and designating the beam pattern having greatest magnitude as the first beam pattern.

6 . The method of claim 1 further comprising, if the measured response in the second beam pattern is within the predetermined error threshold, at least one of 1) displaying a representation of an object corresponding to the first response and 2) tracking the first response.

7 . The method of claim 1 further comprising, if the measured response in the second beam pattern is not within the predetermined error threshold, at least one of 1) eliminating from display a representation of an object corresponding to the first response and 2) eliminating the first response from tracking.

8 . The method of claim 1 , wherein the radar system is a monopulse radar system, and

wherein the step of identifying a response at an identified angle relative to a center of the first beam pattern comprises measuring a first sum beam response and a first delta beam response, and

wherein the step of determining if a measured response in the second beam pattern is within a predetermined error threshold of an anticipated response calculated using the second beam pattern and the first beam pattern comprises 1) determining if a measured second sum beam response in the second beam pattern at an angle relative to the center of the second beam pattern that corresponds to the identified angle relative to the center of the first beam pattern is within a predetermined sum beam error threshold of an anticipated second sum beam response calculated using the second beam pattern and the first beam pattern, and 2) determining if a measured second delta beam response in the second beam pattern at an angle relative to the center of the second beam pattern that corresponds to the identified angle relative to the center of the first beam pattern is within a predetermined delta beam error threshold of an anticipated second delta beam response calculated using the second beam pattern and the first beam pattern.

9 . The method of claim 8 , wherein the sum beam threshold and the delta beam threshold are equal to one another.

10 . A non-transitory storage medium storing program code adapted to be run on a computer processor for processing radar responses of a radar system that produces a plurality of beam patterns, to determine if a given response corresponds to a reflective object, each receive beam pattern projected in a different azimuthal direction, the program code comprising:

for a first beam pattern of the plurality of beam patterns, identifying a first response at an identified angle relative to a center of the first beam pattern;

calculating an anticipated response for a second beam pattern of the plurality of beam patterns, the second beam pattern overlapping the first beam pattern, the anticipated response representing the response expected in the second beam pattern if the first response corresponds to a reflective object; and

determining that the first response corresponds to a reflective object if a measured response in the second beam pattern at an angle relative to the center of the second beam pattern that corresponds to the identified angle relative to the center of the first beam pattern is within a predetermined error threshold of the anticipated response, wherein the anticipated response includes an anticipated sum beam response and an anticipated delta beam response, the predetermined error threshold comprises a quality of match metric including terms based on deviation from the anticipated sum beam response and the anticipated delta beam response.

11 . The non-transitory storage medium of claim 10 , further storing program code comprising determining if the measured response in the second beam pattern is within the predetermined error threshold, and performing at least one of 1) displaying a representation of an object corresponding to the first response and 2) tracking the first response.

12 . The non-transitory storage medium of claim 10 , further storing program code comprising determining if the measured response in the second beam pattern is not within the predetermined error threshold, and at performing least one of 1) eliminating from display a representation of an object corresponding to the first response and 2) eliminating the first response from tracking.

13 . The non-transitory storage medium of claim 10 further storing program code comprising, for a third beam pattern of the plurality of beam patterns that overlaps the first beam pattern, determining if a measured response in the third beam pattern at an angle relative to the center of the third beam pattern that corresponds to the identified angle relative to the center of the first beam pattern is within a predetermined error threshold of a second anticipated response, the second anticipated response representing the response expected in the third beam pattern if the first response corresponds to a reflective object.

14 . The non-transitory storage medium storing program code of claim 13 , wherein the predetermined error threshold is equal to the second predetermined error threshold.

15 . The non-transitory storage medium storing program code of claim 10 ,

wherein the first beam pattern and the second beam pattern are adjacent beam patterns.

16 . A radar system, comprising:

a transmitter to produce RF energy;

a receiver adapted to generate a response upon detecting RF energy, the transmitter and detector characterized by a plurality of receive beam patterns, each of the receive beam patterns extending in a different azimuthal direction; and

a processor to determine if a given response from the receiver corresponds to a reflective object reflecting a portion of the RF energy produced by the transmitter, the processor programmed to:

(i.) for a first beam pattern of the plurality of beam patterns, identify a first response at an identified angle relative to a center of the first beam pattern; (ii.)

(ii.) calculating an anticipated response for a second beam pattern of the plurality of beam patterns, the second beam pattern overlapping the first beam pattern, the anticipated response representing the response expected in the second beam pattern if the first response corresponds to a reflective object; and

determining that the first response corresponds to a reflective object if a measured response in the second beam pattern at an angle relative to the center of the second beam pattern that corresponds to the identified angle relative to the center of the first beam pattern is within a predetermined error threshold of the anticipated response, wherein the anticipated response includes an anticipated sum beam response and an anticipated delta beam response, the predetermined error threshold comprises a quality of match metric including terms based on deviation from the anticipated sum beam response and the anticipated delta beam response.

17 . The radar system of claim 16 , wherein the processor is further programmed to determine if the measured response in the second beam pattern is within the predetermined error threshold, and at least one of 1) display a representation of an object corresponding to the first response and 2) track the first response.

18 . The radar system of claim 16 , wherein the processor is further programmed to determine if the measured response in the second beam pattern is not within the predetermined error threshold, and at least one of 1) eliminate from display a representation of an object corresponding to the first response and 2) eliminate the first response from tracking.

19 . The radar system of claim 16 , wherein the processor is further programmed to, for a third beam pattern of the plurality of beam patterns that overlaps the first beam pattern, determine if a measured response in the third beam pattern at an angle relative to the center of the third beam pattern that corresponds to the identified angle relative to the center of the first beam pattern is within a second predetermined error threshold of a second anticipated response, the second anticipated response representing the response expected in the third beam pattern if the first response corresponds to a reflective object.

20 . The radar system of claim 16 , wherein the first beam pattern and the second beam pattern are adjacent beam patterns.