| 摘要 |
PURPOSE:To make analog value and digital value simultaneously displayable and make the comparison of both data easy by analogically displaying depth data on a CRT and displaying the digitized data of these depth data as the change in the luminance or color of the analog display part of the corresponding depth. CONSTITUTION:The reflected signal from the sea bottom is received in an ultrasonic wave receiver, by which it is converted to an electric signal. After it is amplfied up to a constant level, this level is converted to a digital value by an AD converter 25. The output data of this converter 25 as well as the output data of a counter 31 which starts counting at the same instant when a timing pulse of a pulse oscillator 20 is sent out are recorded in a memory 26. The output of the converter 25 is compared with the value of the set level of a trigger level setter 30 and when the output of the converter 25 becomes more than the set value mentioned above, the output of the counter 31 is recorded in a memory 32 for depth. The recording contents of the memory 26 are converted to analog quantity which is then displayed as a luminescence spot on a CRT35. On the other hand, the count value of the counter 31 at the transmission of the next time and the previous data of the memory 32 are compared and when they coincide, the luminance of the correspondng luminescence spot on the CRT35 is increased. |
