An apparatus for determining a target position within a selected range segment includes a range gate generator (13) which provides a range gate signal that enables a detector (11) for a time interval corresponding to the range segment and a signal generator (17), responsive to the range gate signal, which provides a signal having an amplitude which varies with time. The output signal of the signal generator is sampled by a sample and hold circuit (19). A control signal generator (15) enabled during the range gate interval couples a switching signal to the sample and hold circuit (19) which, upon the reception of a target reflected signal, causes the sample and hold circuit to switch from the sampling mode to the hold mode . The signal amplitude in the hold mode is a representation of the target position within the range gate. Range rate is determined from a knowledge of the elapsed time between range gates corresponding to the same range segment and the difference in positions within the range gates established by the sample and hold circuit when switched to the hold mode upon receptions of the target reflected signals. IMAGE
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