Please note that the Marine Gravitymeter System can only be operated upon request. Request operations with the Marine Gravitymeter System to AWI-Logistics in sufficient time prior to the cruise.

Summary

A gravimeter is used to measure the gravitational field of the earth. The gravimeter on board of Polarstern is situated on a gyro-stabilized platform to compensate for the ships movement. It is a spring and mass system with magnetic compensation, the length of the spring being proportional to the gravitation.


Manufacturer Bodensee Gravitymeter Geosystem GmbH (BGGS)
Model KSS 32 M
Serial No. n/a
Type gravimeter
SENSOR-Link ↪


Contacts

Name Institution Role
Thorsten Eggers Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research Engineer In Charge
Alfred Wegener Institute for Polar and Marine Research Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research Owner
Graeme Eagles Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research Principal Investigator, Data Scientist


Components

The Marine Gravitymeter System consits of the Gravitymeter KSS 32-M and the operator-laptop in the Gravitymeter Room on board. The Gravitymeter control system and data acquisition software BGGS DACQS is installed on the laptop.

Position

Infoxyz-position from Alignment Survey Report RV Polarstern (June 2016), located in F632
X56.99 m
(X-0 is at the center of der rudder (ref. design drawing of the vessel), positive X-axis is forward and along vessel centerline)
Y0.147 m
(Y-0 at centerline, positive Y-axis is portside)
Z11.81 m
(Z-0 is set to the lowest point of the keel, positive Z-axis is upwards)


Data logging, storage and archiving

Logged parameters

Parameter Sensor Output Type Unit
acceleration acceleration m/s2
Gravity gravity mGal


Central geographical ship's position and time standard

Time stamp from DShip NMEA telegram.
A gyro-stabilized platform accounts for compensation of the ship's movements. Navigation data from DShip NMEA telegram.

Rawdata storage on board 

Data storage in DShip system. Rawdata backup to operator-laptop is possible.

Dship

Uncorrected measurement data.


|| Device name | gravimeter || 
|| Parameters | GRAVIMETER.PBGGGD.1.datafield3; GRAVIMETER.PBGGGD.1.datafield4; GRAVIMETER.PBGGGD.2.datafield1; GRAVIMETER.PBGGGD.2.datafield2; GRAVIMETER.PBGGGD.2.datafield3; GRAVIMETER.PBGGGD.2.datafield4 ||

Data archiving on land 

After the cruise the DShip data set can be extracted from https://dship.awi.de/.


|| File format(s) | stored in DShip system || 
|| Calibration certificates | stored in Gravitimeter Room F632 ||

Documentation

The manuals are located in the Gravitymeter Room on board.