Method for detecting radioelectric transmitters and associated device

A method for detecting the presence of one or more radioelectric transmitters in an environment, the method being implemented by a device comprising a computing unit and an antenna array comprising a plurality of antennas adapted to carry out acquisitions simultaneously from the environment in the form of acquisition signals during an acquisition time and to receive and to transmit simultaneously the acquisition signals in digital form to the computing unit, the computing unit being able to carry out processings on the digitised signals, the method comprising:

• for each antenna,
• receiving and digitising the acquisition signal in the form of a digitised signal and transmitting the digitised signal to the computing unit;
• generating a plurality of spectra from the digitised signal having a chosen frequency resolution, a spectrum comprising a plurality of points, each point being assigned to a number called bin;
• for each bin, grouping together the spectra of the different antennas corresponding to the bin and computing a covariance matrix;
• grouping together the covariance matrices of which the associated spectra correspond to a same time block, a time block being defined as a sub-time of the acquisition time, to form block covariance matrices;
• computing a first measurement of co-linearity of the block covariance matrices between two consecutive time blocks and a second measurement of co-linearity of the block covariance matrices between two consecutive bins of a same time block;
• detecting one or more radioelectric transmitters by carrying out the following steps:
• for each bin, computing the product between the first and the second measurement of co-linearity to form a co-linearity product;
• for each time block:
• noting the number of start bins for which the co-linearity product passes above a threshold, that is to say that the value of the co-linearity product for a start bin is above the threshold and the value of the co-linearity product for the bin preceding this start bin is below the threshold;
• the number of start bins gives the number of radioelectric transmitters detected in the time block.