Abstract: The present application is related to a method for detection of a signal, the method comprising the steps of performing continuously a direction finding in time-frequency intervals within a time range and a frequency range, determining for each frequency interval a distribution of the direction finding results, DFRs, for all time intervals and evaluating the determined distribution of direction finding results, DFRs, to detect the existence of a signal emitted by a signal source.

Abstract: An apparatus comprising a plurality of receivers, a controller and memory storing instructions executable by the controller, the instructions, when executed by the controller causing the controller to receive data of signals received via the receivers as a signal from a transmitter, to segment the received data into a plurality of consecutive segments, to determine if consecutive data segments have changed in a manner indicative of movement of the transmitter and to, based on the determination, determine an angle of arrival of the signal based on data segments that have solely been received before or that have solely been received after a detected change in consecutive data segments indicative of movement of the transmitter or that have been received between two detected changes in consecutive data segments indicative of movement of the transmitter.

Abstract: A process for locating radio sources by a two-channel high resolution radiogoniometer including a network of a specified number N of sensors. The process multiplexes the signals supplied by the N sensors on the inputs of only two receivers. Then, with the aid of a calculation device coupled to the outputs of the two receivers, the angles of arrival of the waves emitted by the sources are estimated on the basis of an estimation of the covariance matrix of the signals supplied by the two receivers.

Abstract: Method and device for space-time estimation of one or more transmitters based on signals received using an antenna network. Signals received using the antenna network are separated in order to obtain signals s(t). Signals s(t) are grouped by transmitter, where the signals s(t) are from more than one transmitter, and arrival angles &thgr;mi of the multipaths pm transmitted by each transmitter are determined.

Abstract: The invention relates to a process for locating radio sources by means of a two-channel high resolution radiogoniometer comprising a network of a specified number N of sensors (21 . . . 2N).

Abstract: A process and device related to multisensor radio direction finding receivers usable in radio communication systems including several emission sources. The process and device isolate the contribution of each emission source in sensor signals so as to perform direction finding on a single emission source only, based on learning sequences inserted into waveforms emitted by each of the emission sources. Such a process and device may find particular application to cellular communication networks.

Abstract: A radiocommunications and localization device of the type comprising an array of antennas coupled respectively to a goniometer device and a radio receiver delivering phonic signals to an operator respectively on two headphones. This device includes a device to identify the position of the operator's head and a device for the generation of phonic signals that is coupled to the goniometer device, the radio receiver and the identifying device for the application, respectively to the headphones, of the mutually phase-shifted phonic signals so as to give the operator the impression that the phonic signal that he hears is coming from the direction of arrival of the radiowaves determined by the goniometer device. The applications of this device relate to the radio-localization of persons moving in groups.

Abstract: In order to determine the direction of a beam antenna, at least one magnetic detection device is attached to the beam antenna for measuring at least one of the horizontal and vertical components of the geomagnetic field. Maximum and minimum geomagnetic field data values are obtained from the magnetic detection devices while rotating the beam antenna. Based on output data from the at least one magnetic detection means, one or two possible direction candidates are determined. When the output data has only one possible direction candidate it is either a maximum or minimum value. The direction of the beam antenna is determined from the two direction candidates by specifying one of the candidates depending upon whether a direction of the beam antenna is to the right or left, and determining the direction of the beam antenna from one direction candidate when the output data from the at least one magnetic detection devices corresponds to the minimum or maximum geomagnetic field data.

Abstract: An improved apparatus and method for radio direction finding is set forth, the generic function of which is that of an "automatic bearing indicator" (ABI). The technique and apparatus are intended for use in association with an antenna system which provides two directional beams which are scanned azimuthally in synchronism and are accessible simultaneously at two separate ports. The first beam is characterized by a response pattern having two adjacent, equal, lobes separated by a single, simple, null. The second beam is characterized by a response pattern having a single lobe, aligned in angle with the null of the first beam. The two signals from the two ports of the antenna system are directed via a twin channel receiving means, phase difference and amplitude detection means, and analog to digital conversion means, to data processing means under control of an algorithm which exploits the properties of the phasor (complex number) ratio of the first signal to the second signal.

Abstract: Described herein is a system providing an electronic null-seeking goniometer for use in automatic direction finding equipment. A microprocessor is used to generate sine and cosine information in response to the detected phase of the bearing signal. The microprocessor iteratively locates the transmitter in the null of the cardioid response pattern of the loop and sense antennas, without rotating either the loop and sense antenna set or the goniometer. This eliminates the requirement for moving antenna and goniometer components and is constructed entirely devoid of any rotating machinery. A loop feedback signal functionally related to the detected null angle provides a stable null location method, without audio distortion, at relatively high feedback/signal ratios.