Depth sounder repeater structure and method

DETAILED DESCRIPTION In accordance with the present invention, there is provided a depth sounder structure and method for utilization with a ship's sonar which will provide a remote depth indication of any or all of the above type, and which in particular is capable of providing a digital depth display as well as a display of the ntegrating meter type, either of which may be permanent displays.
Further, the invention includes the steps of and structure for indicating a depth less than a predetermined minimum depth, indicating loss of echo from the ship's sonar, and providing an expanded scale display.
In particular, the depth sounder structure and method of the invention includes signal processor structure for providing signals in accordance with the method of the invention initiated with the transmitted ultrasonic pulses of the ship's sonar and terminated with the receipt of the first corresponding echo received by the ship's sonar.
The pulse output from the signal processor may then be used directly in an integrating meter to provide an analog depth display at locations remote from the ship's sonar.
The signals from the signal processor may also and preferably be used to provide a series of clock pulses of a specified pulse repetition rate, the number of which are determined by the length of the signal processor signals, which digital pulses may then be counted and thus utilized to provide a remote digital display of water depth.
The structure for and method of providing an alarm when a depth below a minimum depth is detected includes structure for and the method of comparing a reference signal, with the signals utilized to provide the depth display from the signal processor and providing an alarm when the relation between the reference signal and the signal processor signals indicates a depth less than the predetermined alarm depth.
The structure for and method of indicating a lost echo from the ship's sonar includes structure operable only on receipt of the echo signal which functions to prevent depth display when the echo signal is not present