Abstract: The present invention provides a coherent radar system based on a modification of standard non-coherent radar without Moving Target Indication. Typical radars in this class are Navigation radars which are mass produced with low cost components. These radars utilize a magnetron in the transmitter which is a random phase device. In the present invention, the received signal is extracted just prior to amplitude detection process (where phase information is lost), and digitized using an analogue to digital converter providing coherent detection based on correlation between the transmitted pulse and the received signal.

Abstract: The present invention provides a coherent radar system based on a modification of standard non-coherent radar without Moving Target Indication. Typical radars in this class are Navigation radars which are mass produced with low cost components. These radars utilize a magnetron in the transmitter which is a random phase device. In the present invention, the received signal is extracted just prior to amplitude detection process (where phase information is lost), and digitized using an analogue to digital converter providing coherent detection based on correlation between the transmitted pulse and the received signal.

Abstract: A method and arrangement for processing signals emitted by a plurality of apparent emitters that is detected by an Electronic Measures System/Direction Finder unit (ESM1). The ESM1 unit is adapted to identify a real emitter and at least one false emitter among said apparent emitters, based on the variance of emitter characterizing parameters for each apparent emitter. When false and real emitters have been identified, this information may be used to suppress clutter from false emitters, and/or to determine the position of the real emitter using observations from only one ESM/DF unit.

Abstract: A method for passively detecting the presence of radar signal emitters, in which an ESM unit receives radar signals with a number of antennas, each antenna covering a sector of the surrounding terrain. In order to conserve bandwidth, a technique is used, in which receiving channel is slit into a number of sub-bands. Each sub-band is converted to an IF channel. The individual IF channels are combined into a common IF channel in an adder. This process is repeated once more in order to bring the signals down to baseband, where they are digitized and processed to find the direction to and the identity of the emitter source. A number of ESM units are connected to a control center. In the control center the position of the radar emitter is determined by triangulation. In addition, the identity of the emitter is determined by comparison with known emitter signatures stored in a database.

Abstract: A digitizer arrangement for converting an analogue signal into a digital signal, including a first A/D converter, said first A/D converter being arranged to convert said analogue signal into a first digital signal with a first sampling rate, the first sampling rate being lower than the frequency of the analogue signal, a second A/D converter, said second A/D converter being arranged to convert said high frequency analogue signal into a second digital signal with a second sampling rate, the second sampling rate being lower than the frequency of the analogue signal, means for combining said first and second digital signals into a third digital signal with a third sampling rate that is at least a multiple of said first and second sampling rates.

Abstract: A method for processing signals in a direction-finder system, including detection of pulses in the received signals, estimation of characterizing pulse parameters, sorting the pulses according to the characterizing pulse parameters, de-interleaving the received pulses into pulses coming from at least one emitter, determining emitter parameters characterizing said emitter, and comparing said emitter parameters with emitter parameters from known emitters in order to recognize and identify the emitter.