Abstract: An apparatus for determining a target position within a selected range segment includes a range gate generator which provides a range gate signal that enables a detector for a time interval corresponding to the range segment and a signal generator, 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. A control signal generator enabled during the range gate interval couples a switching signal to the sample and hold circuit 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.