Method and system for determining a characteristic dimension of a ship

A method for determining at least one characteristic dimension of a ship, the method being implemented by an electronic system including a radar device and a calculator, the radar device including at least two separate channels configured to receive a radar signal, the method comprising:

• acquiring, for each of the two receiving channels of the radar device, a synthetic aperture radar image imaging the ship in an environment, the two radar images resulting from radar signals coming from a same radar emission signal and respectively received by each of the two receiving channels of the radar device, each of the radar images being a matrix of pixels, each of the pixels having an amplitude and coordinates that are a distance box and a doppler box,
• summing the respective amplitudes of the pixels of the two radar images to obtain a sum image;
• extracting pixels from the sum image imaging the ship to obtain a mask of the ship;
• determining a range of phase differences between the radar signals received by each of the two receiving channels, the determining the range of the phase differences comprising
• calculating, for each set of pixels of the mask having the same doppler box, an intermediate phase difference as a function of the radar signals received by each of the two receiving channels and corresponding to the pixels of said set, and
• obtaining the range of phase differences as a function of the calculated intermediate phase differences;
• and
• determining the at least one characteristic dimension of the ship as a function of the mask of the ship and the determined range of the phase differences,
• wherein, for each of the set of pixels of the mask having the same doppler box, the calculating the intermediate phase difference comprises:
• calculating, for each of the pixels of the set, a product of the signal received on the first receiving channel and corresponding to said pixel by a conjugate of the signal received on the second receiving channel and corresponding to said pixel, and
• calculating a sum of the calculated products, the intermediate phase difference for said set being an argument of the calculated sum.