Abstract: An anti-tank trap (1) is constituted by a support (2), a military payload (3), an igniter (4) and a sight (5). The firing on the target is carried out at the time t.sub.d in a plane .DELTA.. The invention is characterized by the following chronological series of stages:first detection by FM/CW radar (lobes 11) and establishment of a first map ERA.sub.ref,second infra-red detection (IR) at t.sub.2 (plane V or V'),third IR detection at t.sub.1 (plane U or U'),computation of: t.sub.1 -t.sub.2 and of the angular velocity d.gamma./dt of the target,fourth detection by FM/CW radar (ERA.sub.m),measurement of the range d.sub.c and of the size of the target (ERA.sub.m -ERA.sub.ref),analysis of the target, firing decision, computation of t.sub.d and triggering at t.sub.d of the military payload.Application to an anti-tank trap.

Abstract: The arrangement (201) comprises an optical narrow detection beam (203) focussing system for a passive infrared radiation in accordance with a reference plane (U). A filter selects the spectral analysis band and at least one passive infrared radiation detector is provided in the focal plane. According to the invention, the arrangement comprises a first analog processing chain and a second digital processing chain by means of which it is possible to recover in accordance with a characteristic curve at least the undercarriage of vehicles. On this curve, each turning element of the undercarriage assumes the shape of an identifiable pulse. The arrangement is used in the identification of moving vehicles in a predetermined plane.

Abstract: The sensor (1), of the FM-CW type, comprises a transceiver aerial (2) which is rigidly attached to the support of the sensor and is of the frequency scanned beam steering type. The sensor radiates a frequency F of several GHz according to a sawtooth pattern which is nearly linear, generates a beat signal (F.sub.b) between a transmitted wave and a received wave an comprises an analog processing circuit (17) for the signal F.sub.b, digitizing means for F.sub.b (22), memories for time-division samples (28) and frequency-division samples (33), and digital processing means (31) transforming sequences (SU) of time-division samples into sequences (SV) of frequency-division samples. The order number of each sequence is representative of a strip of pixels of the map and the order number of a sample in a sequence is representative of a distance of a pixel on the map.