| Summary: | Progress Code: completed Statement: Routine Trawls were approximately every second CTD station. The target trawls were conducted when an interesting trace was seen on the echo sounders. The RMT CTD calibration was completed prior to departure. The quality of the sensor data are as reported in the referenced calibration reports. The net open time is not 100% accurate as there were times when the net was jerked open, but these times were not noted. There is no way that this time can be corrected. The CTD data were acquired when the RMT instrument was in the water. Data Acquisition: There is a FSI CTD sensor housed in a fibreglass box that is attached to the top bar of the RMT. The RMT software running in the aft control room establishes a Telnet connection to the aft control terminal server which connects to the CTD sensor using various hardware connections. Included are the calibration data for the CTD sensor that were used for the duration of the voyage. The RMT software receives packet of CTD data and every second the most recent CTD data are written out to a data file. Additional information about the motor is also logged with the CTD data. Data are only written to the data file when the net is in the water. The net in and out of water status is determined by the conductivity value. The net is deemed to be in the water when the conductivity averaged over a 10 second period is greater than 0. When the average value is less than 0 the net is deemed to be out of the water. New data files were automatically created for each trawl. Data Processing: 1. Adjustment of the net open time. If the net did not open when first attempted then the net was 'jerked' open. This meant the winch operator adjusted the winch control so that it was at maximum speed and then turned it on for a very short time. This had the effect of dropping the net a short distance very quickly. This dislodges the net hook from its cradle and the net opens. The scientist responsible for the trawl would have noted the time in the trawl log book ...
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