| 摘要 |
PROBLEM TO BE SOLVED: To make it possible to detect a wake in real time by providing a wake detection device with a means for respectively calculating the mean value of pixels in a rectangular area and the mean value of frame-like areas surrounding the rectangular area and a means for respectively detecting an area indicating a ship and the center of the ship by labeling the area. SOLUTION: A vessel detector 15 detects the area of a vessel and the center point of the area. Thereby, a mean value and a standard deviation are found out by the amplitude value of an area indicated by a frame, and a threshold is obtained by adding a fixed multiple of the standard deviation to the mean value. Then data including vessel areas detected by moving a vessel area detection filter on SAR amplitude image data 6 in every pixel are labeled by a four-connection component. Furthermore, the center point is extracted from respective labeld vessel areas. A vessel existence discriminating device 16 discriminates the existence of a vessel wake based on the extracted center point of the vessel, and when there is a wake, the vessel area is shifted from the center point of the vessel in the azimuth direction by one pixel to specify the wake.
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