Spatial statistics of instrument-limited angular measurement errors in phased array radars

The major contributors to the random component of the instrument limited angular measurement errors in electronically scanned phased array radars are reviewed and formulas are developed for statistical modeling of these error sources. The error model employed is applicable to space-fed and certain types of corporate-fed arrays. A comprehensive computer program, embodying this analysis, has been developed for determining these array measurement errors and their spatial correlation statistics, in two angle variables. This program is used to evaluate the statistical behavior of angular errors for some typical situations of interest. The use of angle, frequency, and phase "dithering" for improving the correlation statistics of these arrays is examined. The phase dithering technique is shown to be at least as effective as angle and frequency dithering and has the virtue of being readily implemented in the beam steering computer.