This section refers to the procedure involving the instrument, cables, power, and rosette. Basically, it is the part of the procedure you carry out in association with deployment and recovery of the rosette.
When approaching a station to do a CTD cast, you need to have the instrument pinging and disconnected from power and communications (with cable ends properly dummied and secured) before the rosette is ready to deploy. Depending on your comfort level with all the steps and the status of the rosette, this could be as little as 5 minutes before “on station”. However, we (the LADCP people) DO NOT want to be responsible for any delay in deploment. Often the instrument is made to ping more like 10-15 minutes before arrival on station. The longer the instrument pings on deck, the greater the file size to download, and the longer the battery will have to recharge. But, we do not want to get in the way or cause any kind of delay. At the beginning of a cruise, err on the side being “ready to deploy” with time to spare, and later in the cruise trim that time down as the situation allows.
The LADCP operator may also help deploy the rosette.
15-20 minutes before “on station”:
Start a new acquisition logsheet (See this example logsheet)
Start data recording (see Section Prepare for data recording) and write down time when the instrument starts pinging
The LADCP instrument is ready to go.
The rosette is brought on board. People are milling about, anxious to start sampling. The LADCP person should be standing by (or maybe that person helped with the recovery), and as soon as the rosette is officially “secured”, before sampling starts, the LADCP person should connect the cables for power and communication.
The LADCP person may participate in drawing water for salts or other rosette sampling, as long as they are able to monitor the download and charging process, assess the quality of the data (pass/fail) and perform any necessary troubleshooting. Helping with the sampling is up to the workload and interest of the LADCP operator: it is not one of our requirements.
1. Output from the power supply or charger should be OFF. This is a safety precaution for persons and equipment. Double-check if in doubt.
In the wet lab, toggle power on (lower right-hand button on the Amrel power supply, or turn on power strip) to charge the SOB.
Download and check the data (see Section Recover the data).
Once the battery is charged (drawing 0.5A/channel or green light is on) toggle off power.