Patent ID: 6868041
Filing Date: 2005-03-15
Classification: G01S,G01V

Abstract:
1. A method of enhancing an image of a survey area comprising the steps of: (a) transmitting sonar pulses from a reference origin repeatedly towards the survey area; (b) measuring the amplitudes of echoes received at the reference origin, said echoes being scattered back from a plurality of survey points in the survey area, each survey point having a known position measured from the reference origin; (c) calculating the range to each survey point as the distance from the reference origin to each survey point; (d) calculating the angle of incidence at each survey point as the angle between a line from the reference origin to each said survey point and a vector normal to the survey area at each said survey point; (e) compensating the amplitude of the echo for each survey point by applying a selected function of the range and angle of incidence to adjust for the attenuation of the echo amplitude due to range and angle of incidence; thereby to obtain an enhanced image of the survey area.