Optimal Direction Finding with Partially Calibrated Arrays

Thi s paper i s concerned with the problem of optimal (maxi-mum likelihood) direction of arrival ( D O A) estimation in situa-t ions where the sensor array is calibrated over only a portion of the DOA space. Situations such as this of ten arise i n aiTborne direction f inding when skywave multipath i s present. A parame-terization is proposed for partially calibrated arrays (PCAs), and the identifiability of the model is discussed for both uncorrelated and correlated signals. I t i s shown how the signal and noise subspace fitting algorithms are generalized to handle PCAs, and a detection scheme is proposed for individually determining the number of signals arriving f r o m Calibrated and uncalibrated d i-rections. T h e results of several simulation examples are included t o validate the analysis. 1