| 摘要 |
A method for measuring depths of a waterway, including the steps of determining nautical chart vertical reference values along a selected waterway, building a data base of the reference values and storing the data base in a computer accessible from the vessel, providing a radio receiver onboard the vessel and Global Positioning System (GPS) equipment accessible from the vessel, and operating the computer, radio receiver, and GPS equipment to continuously obtain positions of the vessel horizontally, and computations as to depth of the vessel above a pertinent vertical reference value. |
