Method and means for providing frequency agile operation of MTI (Moving Target Indicator) radar

The obtaining of simultaneous pulse-to-pulse transmitter carrier frequency agility and compatible moving target indicator (MTI) operation in conventional surveillance radars is achieved by the use of pairs of frequencies with a controlled relationship between the frequencies of each pair. A set of four pulses with different frequencies is sequentially transmitted and form two pairs of pulses. The difference between the frequencies of one pair of pulses is made equal to the difference between the frequencies of the second pair of pulses. MTI operation is obtained by differencing the pairs. Pulses having any three frequencies may be selected in any sequence before a constraint is imposed. The frequency of the fourth pulse is then determined by the frequencies of the first three pulses.