once a base set of angles is determined by formula other angles may be determined by sums and differences derived first sensor image angles before angular measurements between triplets of the second sensor image second sensor image angular measurements may be determined the second sensor image may be rotated to align its range axis the second sensor image range axis to the range axis of the first sensor image the first sensor image range axis this is performed in block 540 and may necessarily involve rotating the axes of the second sensor image as will be understood rotating the second sensor image to align its range axis with the first image may for example be performed when the images are 3 dimensional but only 2 dimensions are being evaluated or when the relative rotation of the range vectors is small if the range to targets in an image varies significantly and the rotation is large 3 dimensional angle correlation methods may be appropriate to correlate the clusters in the first and second images then at block 550 angular measurements between triplets of objects of the rotated second sensor image second sensor image triplets of objects are determined as with the angular measurements of the first sensor image some of the angular measurements of the second sensor image may be determined by formulas 2 and 3 calculated second sensor image angles and some may be determined by sums and differences derived second sensor image angles finally in block 560 angular measurements in the first sensor image are correlated to angular measurements in the second sensor image.