High accuracy measurement of sea current by navigation electric wave and acoustic waves.
An acoustic sea current-meter, in combination of a position measuring device navigation electric wave, log an acoustic log and a gyro compass, has been developed and used practically as the equipment for surveying sea current in vast and deep sea in 3 dimensional manner. However, this equipment presently suffers from lower measuring accuracy in deep sea than in shallow sea because of lower accuracy for measuring velocities in relation to land using navigation electric waves. This report describes a new method for achieving a level of accuracy about 10 times as high. According to the method, the same data as conventional practice is used for measuring velocities to land using navigation electric waves. However, only incremental components of measured time differences are dealt with for converting velocities. Another merit of the new method higher operating rate of calculation. The new electric wave log is assembled in conventional meter, thus realizing high accuracy metering of sea current even in deep sea. In addition, it is also reported that the new electric-log is capable of comparing frequencies of received waves to a reference frequency at the receiving point, in high accuracy, and also applicable to measuring frequencies of a standard oscillator.
| Main Authors: | , |
|---|---|
| Format: | Journal Contribution biblioteca |
| Language: | Japanese |
| Published: |
1989
|
| Online Access: | http://hdl.handle.net/1834/16112 |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|