Radar apparatus

1. A scan-to-scan integrator for use in radar apparatus, comprising:

window defining means for defining a search window for use in verifying a candidate detection, the window being bounded by an intersection of a first zone and a second zone so as to be smaller than the first and the second zone, the first zone comprising a rectangular detection window relative to a Cartesian reference frame, and the second zone comprising a range estimate tolerance region defined by a range estimate for the candidate detection and predetermined tolerance limits, this second zone being bounded by arcuate bounds centred on an antenna of radar apparatus with which said integrator is employed.

2. The integrator of claim 1 , wherein the integrator is operable to integrate over successive scans, and operable to output a detection signal on positive detection of a target detection in said window a predetermined number of times.

3. The integrator of claim 2 , wherein the integrator is further operable to receive a user input action defining a number of scans over which scan to scan integration is to be performed, the integrator comprising a detection count determining means operable to determine a detection count threshold on the basis of said number of scans, said integrator being operable to output a detection signal on positive detection of a target detection in said window a predetermined number of times at least as great as said detection count threshold.

4. The integrator of claim 3 , further comprising target motion estimation means operable to determine an estimated motion of said target relative to radar apparatus with which the scan to scan integrator is to be used, and wherein the window defining means is operable, for each scan, to determine said window on the basis of said target motion estimate.

5. A method for integration of radar detection signals for presentation of radar detection output to a user, the method comprising:

generating a radar detection output on the basis of successful verification of a candidate detection if said candidate detection is confirmed a number of times exceeding a threshold relative to a number of scans to be performed, the step of the candidate detection further comprising the steps of:

defining a rectangular search window relative to a Cartesian reference frame within which to seek the candidate detection,

determining a range window within which the candidate detection is to be sought, the range window being bounded by accurate bounds centred on an antenna of radar apparatus with which said method is employed, an intersection of the rectangular search window and of the range window being smaller than each individual window, and

if the candidate is detected within the rectangular search window and within the range window, then confirming the candidate detection.

6. The method of claim 5 , further comprising the step, in each scan except the initial scan, of determining the range estimate for the scan on the basis of information from the previous scan.

7. The method of claim 5 , further comprising receiving a user input action defining a number of scans over which scan to scan integration is to be performed.

8. The method of claim 7 , comprising determining a detection count threshold on the basis of said number of scans, and

outputting a detection signal on confirmation of a target detection in said window a predetermined number of times at least as great as said detection count threshold.

9. The method of claim 5 , wherein the number of scans over which scan to scan integration is to be performed is predetermined.

10. The method of claim 5 , further comprising determining an estimated motion of said target relative to radar apparatus in which the method is employed, and

determining the window, for each scan, on the basis of said target motion estimate.