ACCURACY REQUIREMENTS IN OFF-LINE ARRAY CALIBRATION

Practical sensor arrays are characterized by certain physical paramete rs, related to the array shape and its electrical properties. Accurate direction finding requires calibration of these parameters to a relat ively high accuracy. Depending on the application, calibration may be performed either off-line or on-line. Off-line calibration is performe d by transmitting signals from known locations and measuring the array response. The array parameters can then be estimated by maximum likel ihood, least-squares, or some other algorithm. This work relates the p arameter estimation accuracy achieved in off-line calibration to the d irection-of-arrival (DOA) errors during on-line operation. it then pro poses a criterion for choosing the off-line calibration points (number and location) so as to meet on-line accuracy requirements.