Abstract: A correlation radar system utilizes a switching logic circuit for automatically switching a code word having a predetermined number of bits directly to a transmitter and through a delay to a receiver of the system and, alternately, directly to the receiver and through a delay to the transmitter. By utilizing the switching circuit, the delay need only produce up to one-half the number of bits in the code word.

Abstract: A modified maximal length PRC (pseudo-random code) sequence generator for use in autocorrelating systems such as CW, bi-phase modulated PRC radar systems. The code generator for the system is a modified version of a known shift register and feedback arrangement, which provides a wordlength of 2.sup.n - 1 as known in the prior art. Means are shown for adding a zero in the sequence of n-1 zeroes which always occur within the PRC word according to pseudo-noise theory. The result is an autocorrelation function having no residual value for several bits on either side of the correlation peak, thereby providing a theoretically infinite range discrimination in the near vicinity of a true range value.