摘要 |
A method for sonic analyzation on-line and in real time or off-line in post processing of a topographic representation of a seafloor to provide the latitude and longitude of an object producing a corresponding anomaly appearance identified in a topographic respresentation generated from a side scan sonar tow fish includes in the on-line, real time analyzation the steps of sequentially touching the tip of a sonic digitizer stylus to a point on the line representation of the seafloor laterally opposite the appearance of the anomaly; to the leading edge and the trailing edge of the anomaly and to the tip of an acoustic shadow of the anomaly appearance; and, if length is desired, to the top and bottom edges of the anomaly appearance. A computer includes a set of instructions to calculate the desired information and is coupled to a host computer associated with a vessel which tows the sonar tow fish along a course covering an area of interest of the seafloor. The computer receives the position, speed and heading of the tow fish at each point contacted by the stylus tip and calculates the latitude and longitude, height, length and width of the corresponding object. In the off-line post processing mode the stylus tip is touched to a calibration point prior to the anomaly analysis and to a fix mark immediately before and after an identified anomaly and inputting the latitude and longitude associated with the respective fix marks. The remaining steps in the post processing mode are similar to the on-line, real time analysis. |