06/01/2012 — admin
The point of the QAT visit was to help the host institution in developing protocols and practices that are conducive to the acquisition of high quality multibeam data. Even with a finely tuned and calibrated survey system, it is still possible to collect poor quality data through poor choice of operational system parameters, etc. Software tools to aid in this regard were deployed and documentation was prepared that can help return the system to a healthy configuration such that the institution can recover from a sub-optimal system configuration. Current awareness of the importance of maintaining a “chain of custody” on the survey system geometry is high. It is recommended that procedures and training be given to all technical staff to maintain awareness of the fact that changes to the system geometry must be adequately documented.
It is recommended that the technicians familiarize themselves with the software and documentation provided during the cruise. Revisions, corrections, criticisms and suggestions are welcome and will improve future efforts to help other vessels in this regard.
Though the EM710 has yet to undergo a sea acceptance trial, preliminary data indicate that it is functioning as expected without any issues or problems being immediately apparent in data from the system. The larger issue that dominated most of the cruise was that the EM122 system was clearly underperforming. Examining the water column data, it is clear that noise is a limiting factor in the ability of the system to track beyond 1x water depth. Based on the noise level measurements made during the transit, however, it is not likely to be due to high acoustic noise levels. The nature of the observed noise is markedly different from that of the Healy and points to perhaps problems inherent to the EM122 system itself and not the ship. This conclusion is further supported by the fact that increased coverage was obtained when operating in 1°x4° mode where parts of the signal processing chain are removed.
|2012 Kilo Moana QAT Final Report (.pdf)||12.41 MB|
|Kilo Moana 2012-03-12 EM122.tgz System Configuration (.tgz)||27.33 MB|
|Kilo Moana 2012-03-12 EM710.tgz System Configuration (.tgz)||17.52 MB|
|Kilo Moana 2012-03-12 POSMV System Configuration (.tgz)||1.13 MB|