The shape of sum and difference beams can be severely distorted if nulls in
jammer directions are formed. In a previous paper a correction formula was
developed that can be applied to monopulse estimation with subarray output
adaptive arrays as well as to generalised sidelobe canceller (GSLC) config
urations. The present paper derives the probability density function for su
ch monopulse estimators with given adaptive beams for Rayleigh targets and
jammers. With this both mean and variance can be easily calculated. For non
fluctuating targets and gaussian jammers formulas for the mean and variance
are given which have to be evaluated numerically. These results can be use
d to analyse the performance of different corrected adaptive monopulse sche
mes. In particular it is demonstrated how the bias and variance of the mono
pulse estimates depend on jammer location, SNR, type and number of subarray
s or auxiliary channels for the GSLC.