Expedition 395: North Atlantic Mantle Convection and Climate

Technician: Mark Higley

PDR

After attempting to use the new iRIS PDR calculator, a discrepancy between the excel worksheet and the IRIS calculator was noticed. The issue seems to arise when the corrected depth to transducer is calculated so only the uncorrected depth (from the bathy) and the Mathews Tables are involve at this point. Upon inspecting the labview code, the math involved was different from how the PDR corrections are done in the excel spreadsheet. The labview code was modified so that the math matches what is done in the excel spreadsheet and the application was installed on the big screen in the LO office. The values in the excel speadsheet and the iRIS application now match.The updated PDR iRIS app was installed on the big screen computer in the LO office.

Open

Echosounder

The 12 kHz single-beam echosounder was used for all transits and worked very well including occasionally picking out sub bottom features.

MRU

No issues with the MRU but it is still not set up to transmit to the bathy computer.

Gyroscope

The gyroscope continues to transmit empty packets occasionally but the number of emptry packets never increased sufficiently to put helmsmen into a critical (red) state. This may be due to the fact that navipac had to be restarted many times during the expedition in order to change the  UTM zone. so the counters were reset during this process.