Abstract: The initial detection of a signal of interest in a data stream involves transmitting a signal received by a sonar or a radar to signal detection equipment wherein a signal of interest is characterized by a state model x(t) with values in a finite set {x1, . . . , xN}, to which there corresponds a finite set {?1, . . . , ?N} of N values of an observation variable ?, characteristic of this signal. To detect the signal of interest a detection criterion ?n(t) is simultaneously calculated in two different ways. The larger of the two calculated values is assigned to the criterion of ?n(t) which is then compared with a detection threshold.

Abstract: The present invention relates to the general problem of detection by sonar or radar. It is concerned in particular with the initial detection of a signal of interest in a data stream corresponding to the signal received by such equipment. This initial detection is transmitted to the equipment charged with performing the tracking of the objects of interest that were the subject of a detection. The method considers that a signal of interest is characterized by a state model x(t) with values in a finite set {x1, . . . , xN}, to which there corresponds a finite set {?1, . . . , ?N} of N values of an observation variable ?, characteristic of this signal. To detect the presence of a signal of interest the method simultaneously calculates the value of a detection criterion ?n(t) in two different ways.