TABLE OF CONTENTS A special application of search-radar theory applies to the problem of target acquisition by a narrow-beam tracking radar. This section will review this special case, considering the type of designation data made available to the tracking radar, the errors in these data, and the requirements for reliable target acquisition.
During acquisition the tracking radar operates in the search mode over a limited volume of space. The search radar equation (1.23) determines the range at which a tracker can acquire its target. The search solid angle ? s must be large enough to ensure a high probability that the desired target lies within the scan. The scan frame time t s and the detection probability per scan are specified so that the required cumulative probability of acquisition P ca is obtained within a time t a. The acquisition range R m increases when the search angle is reduced by high-quality designation data. In the limit, the tracker beam is pointed at a known target position, and signal integration over the entire time t a can be used to detect targets at low SNR. The acquisition capability of the radar is maximized if the signal processor has the ability to integrate signals in many range and doppler cells, covering the uncertainty volume in those coordinates.
Designation of the target can come from sources of differing accuracies in each radar coordinate.
