| 摘要 |
PURPOSE:To obtain distance information and speed information and to improve the working efficiency of a transmission signal by performing echo display and Doppler display in black-and-white and color simultaneously with the sum and differential signals of two kinds of A mode signals obtained by frequency-analyzing two signals in up-chirp and down-chirp. CONSTITUTION:An image processing circuit 21 performs the addition arithmetic operation and the subtraction arithmetic operation of two signals in the up-chirp and down- chirp of the transmission signal from the same echo source of an inputted A mode image signal, and the sum and differential signals can be obtained. As the sum signal, a signal with the same beat frequency is outputted to a fixed target, and a signal with beat of 1/2 of the difference at the mean frequency position of beat frequency of reception signals for two times is outputted to a mobile target. As for the differential signal, output by an echo from the fixed target goes to 0, and the output by the echo from the mobile target shows the one as shown in figure. The image processing circuit 21 further integrates the signal, and the signal with amplitude in proportion to Doppler shift can be obtained. An obtained sum signal from the fixed target is displayed as a B mode image shown in black-and-white display, and the differential signal as Doppler mode image in color display on a display device 22. |
