An apparatus for detecting a dispersive object in non-dispersive clutter comprising a multi-frequency radar, a signal processor which computes the elapsed time between when each frequency is transmitted and that same frequency is received and the dispersion statistics related to the several frequencies. A dispersion analyzer produces a dispersive object discrimination value which is compared with a threshold by which a detection is declared. The apparatus also utilizes dispersion statistics to differentiate between dispersive and non-dispersive radar returns in order to reject the non-dispersive signals and pass the dispersive signals to a signal integrator which increases the signal-to-clutter ratio thereby improving the probability of detection of subsequent target detection processes.

A system and method are for reducing the probability of detection of a Line of Sight type communication and sensor mast. The mast has an upper portion extending upwardly relatively the ground, and a lower portion closer to the ground than the upper portion. The mast at the upper portion is equipped with at least a communication or sensor element. The mast is equipped with an actuator that, based on calculated instructions, is designed to alter the elevation above ground of the mast upper portion so as to achieve an acceptable signal quality with the upper portion of the mast at the lowest possible elevation.

A radar and method for making a radar undetectable, comprising comprises: on a transmit antenna consisting of N individual subarrays that are non-directional in at least one plane in transmission, each being linked to a waveform generator, generating, for each of the individual subarrays, a waveform so as to make each of the individual subarrays transmit continuous or quasi-continuous signals according to a temporal and periodic pattern by using transmission patterns made up of N different subarrays and which are deduced from one another by an individual delay, on the receive antenna comprising M individual subarrays adapted to pick up the reflected signals obtained from the transmission of the N individual subarrays of the transmit antenna, performing a compression of the received signal in space and in time of the received signals.