11/04/2015 — admin
- The EM 122 receive array had a bad preamplifier board that was causing the entire array to have higher noise levels and to exhibit non-uniform distribution of noise characteristics.2.The EM 122 receive array module 6 was out of phase with the rest of the sonar receive array.
- The EM 122 receive array module 6 was out of phase with the rest of the sonar receive array.
- Propeller cavitation performance was good and consistent with previous results.
- Following a modification to the bad preamplifier board, acoustic levels of the EM 122 sonar were considered acceptable and similar to levels measured in 2012.
- Following a temporary phase shift of module 6 to correct the phase deficiency, sonar operations were good and will allow for good science data acquisition
- Noise from diesel engines was determined to not be the source of excessive sonar noise.
- A sewage room rattle was detected and should be corrected when possible.
- Replace bad sonar preamplifier board.
- Ensure all sonar modules are in phase with each other.
- DOCUMENT all temporary fixes to the sonar so future operations issues are easier to diagnose.
- Correct rattle in sewage room.
- Install a permanent acoustic monitoring system to allow for shipboard personnel to listen to reference hydrophone data and to acquire and analyze this data during real time operations
|KILO MOANA ACOUSTIC TRIAL AUG 2015-reduced.pdf||3.73 MB|