| 摘要 |
A solid state depth sounding system, for measuring depth and detecting the presence of underwater objects, comprises an oscillator, producing high frequency electrical signals, a transmitter, for intermittently amplifying those signals, a transducer, and a receiver. The transducer produces high frequency sound impulses from the intermittent amplified signals, and transmits those impulses through the water until they are reflected by some underwater object. The transducer also picks up the reflected sound impulses and provides a high frequency electrical signal to the receiver which amplifies and detects it to produce a return pulse related in analog value to the strength of the reflected signal. The time delay between the transmission and reception of the high frequency sound impulse, and consequently the distance to the reflecting object, is measured by applying either a transmit pulse or a return pulse to the serial input of a multibit BBD or CCD shift register with a specified number of parallel outputs. When the contents of the shift register are sampled, the pulse or pulses in the register are used to drive display elements corresponding to the bit or bits in which those pulses are found. A properly calibrated display, driven by these pulses will indicate the presence and depth of underwater reflecting objects. By applying the analog return pulse to the input of the shift register, and by sampling at predetermined intervals the display will indicate, by the relative intensity of the driven display elements, the relative strength of the reflected signals. A number of such solid state depth sounders may be used to provide multidirectional depth measuring and detection with a single coordinated display. The display device and signal processing equipment are designed to indicate the lateral distance to a reflecting object as well as its depth.
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