Abstract: A receiver for pulse amplitude modulated TACAN signals having 15 Hz and 135 Hz modulating components and which determines the TACAN bearing angle by calculating the phase shift angles .phi.15 and .phi.135 of those components of the received signals. The amplitudes of the received pulses and their times of arrival over a given time interval are stored in a memory. From such stored values a microprocessor determines the elements of a column vector Z defined by the pulse amplitudes and arrival times, and the elements of a matrix M defined by the arrival times. A column vector X corresponding to M.sup.-1.Z is calculated, the elements of which are trignometric functions of .phi.15 and .phi.135, from which those phase shift angles are determined. The TACAN bearing angle is then evaluated from the phase shift angles without requiring circuits to phase lock them with respect to each other.

Abstract: A control device suitable for synchros comprising three stator windings. The device comprises four circuit branches with the inputs of the first and the second branches interconnected to receive a first voltage from the ends of the stator windings of the synchro transmitter and with the inputs of the third and the fourth branches interconnected to receive a second voltage from the ends of the stator windings of the synchro transmitter. Two adder elements supply control voltages to the stator windings of the synchro receiver. Two inputs of the first adder are connected to the outputs of the first and the third branches, respectively and the two inputs of the secnd adder are connected to the outputs of the second and the fourth branches. These branches have transfer functions in the form sin (.alpha.+.phi.1), sin (.alpha.+.phi.2), sin (.alpha.+.phi.3), sin (.alpha.+.phi.4), respectively, wherein .alpha. represents the information supplied by a digital element and .phi.1, .phi.2, .phi.3, .phi.

Abstract: A radio distance measuring equipment emits a frequency modulated carrier wave signal, having a periodic frequency deviation .DELTA.F and a mean frequency F.sub.o, toward an object, and receives a portion of the carrier wave signal reflected by the object. A beat signal produced by mixing the emitted and received signals is applied to a control loop which determines the distance. Operation of the equipment is periodically interrupted, under the control of a microprocessor, to effect calibration of the frequency deviation and the mean frequency.

Abstract: This indicator preferably comprises two belts; one of the belts having graduations and the other belt a mark. This mark which has been preset to one of the graduations must be moved in the same manner as the graduated belt so that the agreement is maintained. According to the invention, two controls have been provided for driving these belts the input quantities whereof are processed by an arithmetic unit, for example a microprocessor.