Abstract: A method for displaying a battle situation under consideration and indication of the movement and position of friendly forces and with the position and motion behavior of targets being derived from angle and distance information, wherein: the display takes place on an electronic display device; one or a plurality of passive bearing systems and/or passive distance measuring systems are provided to furnish angle and distance information of targets which radiate wave energy; position, course and speed are calculated for every target per time interval and displayed as motion vectors; angle and distance information on the targets from given time intervals are used for the display of target paths; markers are associated with the targets resulting from their changes in position and/or the characteristics of signals received from the bearing and/or distance measuring systems and these markers are displayed at the associated target positions; and uncertain measurement regions are calculated from the measuring toleranc

Abstract: An improved sonar system of the type wherein a plurality of acoustical beams are transmitted with directional characteristics which are simultaneously swept over adjacent sectors of the observation area. The transmitting directional characteristics of each pair of adjacent sectors are swept or pivoted over their respectively associated sectors in a continuous manner and in opposite directions so that they leave and reach the common borderline between the sectors at the same instant of time.

Abstract: Apparatus for locating sources of sound in water, including a hydrophone system which is suspended from a buoy after being dropped into the water and whose one given reference axis is automatically aligned with the magnetic field of the earth by mechanically coupling the hydrophone system with a compass magnet (north reference). The hydrophones of the hydrophone system are electrically connected with a switching or control box by means of transmission wires which are insulated with an elastic plastic and pass freely through the water and the hydrophone system is mechanically fastened to the switching box to be rotatable in a recoilless manner about an axis which is perpendicular to the surface of the earth. The control box is in turn connected to the buoy by means of an elastic suspending cable and an electrical connecting cable.

Abstract: An improved system for determining the direction of impingement of a received energy signal, of the type having a plurality of receivers forming pairs of mutually perpendicular dipoles for receiving the orthogonal components of the impinging signal, apparatus for measuring these received components in order to produce signals indicative of the direction of impingement, and a display device connected to the output of the measuring apparatus. The measuring apparatus is provided with a plurality of amplifier circuits each of which is connected to a respective one of the receivers for producing a constant amplitude representation of its received signal. The use of these amplifiers helps to eliminate errors that would otherwise occur in the measurements due to inaccuracies in the measured amplitudes of the received dipole signals.