Abstract: A system for determining the average water film thickness on surfaces, and in particular roadways, with the reflection of microwaves on the surface of the film of water being measured. To be able to easily measure water film thicknesses of several millimeters without contact and with great accuracy, the system includes at least two partial systems which each comprise a signal source and a receiver. The individual partial systems operate at different frequencies which are selected such that the maximum accuracy measuring regions associated with the respective frequencies are contiguous and cover the predetermined water film thickness range to be determined. The partial systems are connected with a sampling and control device which activates at least that partial system which exhibits maximum measuring accuracy for the respective water film thickness being measured and utilizes only the output signal from the receiver of that partial system for the measurement.

Abstract: A target detection method for a flying body provided with a search head, with the flying body rotating during its descending flight and scanning the area for possible targets, and in which the geometric dimensions of possible targets are determined in the scanning direction (Y direction) and in a direction perpendicular to the scanning direction (X direction) and are compared with corresponding stored values to determine the presence of a target. To avoid distortions of the scanned target in the Y direction, at least the angular velocity .omega. of the flying body, and preferably also the angle .phi. between the axis of rotation and the symmetry axis of the flying body, is continuously determined during the scanning process and, image correction values are calculated from the determined values and used to correct the geometric dimensions of the possible target in the Y direction.

Abstract: An inductive energy converter includes a coil assembly having coil windings, with at least some of the coil windings respectively having spaced contact regions. A contact bar within the coil assembly is insulated from the coil windings, and a conductive body is in electrical contact with the contact bar and is movably supported by the coil assembly, wherein movement of the conductive body brings it into electrical contact with consecutive ones of the spaced contact regions, to complete an electrical circuit between one of the windings and the contact bar.

Abstract: A projectile intended to be fired from an electric rail gun having spaced current-carrying rails between which the projectile is accelerated when fired, includes an armature mounted on the projectile and arranged to make contact simultaneously with the rails to electrically connect the rails to one another. The armature is of annular configuration and rotates as the projectile is propelled through the electric rail gun.