Patent ID: 7489267

Claim:
A radar apparatus comprising: a data receptor which is configured to sequentially receive reception data of a polar coordinate system obtained by rotation of a sweep; an image data storage which is configured to convert the reception data of the polar coordinate system to image data of a rectangular coordinate system, and to store the image data such that all of the image data is updated according to the reception data for each rotation of the sweep; a subtraction characteristic determinator which is configured to, based on at least one of the planar consecutiveness or the time-wise continuity of the points of reception data obtained by the data receptor, determine a subtraction characteristic with which a data level of the corresponding image data is reduced at each of a subtraction timing that is shorter than the period of one rotation of the sweep; an image data subtractor which is configured to, based on the subtraction characteristic, reduce the data level of the image data that has been written to the image data storage at each subtraction timing, and to store the updated image data in the image data storage; and a display which is configured to successively read out and display the image data that has been stored in the image data storage.