FIELD CAMPAIGN
Multi-beam sonar survey with autonomous under water vechicle
Team: Peter Wadhams, Martin Doble, Jeremy Wilkinson, 2 GAVIA techs
Aims
This is the first sea ice misson for Gavia. Hence our first goal is to ensure safe and efficient opporation of the AUV under sea ice.
Estimate ice draft distribution within 1km range of camp. With particular emphasis on estimating ridged ice contribution to the distribution.
Perform a collocated EM-bird, AUV transect, to investiage the utility of both istruments in estimating ice thickness distribution.
Should the AUV pass tests of opperation under sea ice with efficient recovery, we will perform a survey at the ridge study site. Aim of this survey will be to determine shape and volume of the keel, and to estimate the distribution of block sizes incorporated in the ridge.
Performance Tests
The first AUV deployments will be within 200m of the deployment hole, and in the direction of level ice. The runway would be the ideal location for these tests.
Before the AUV will be allowed to roam further, it must be demonstrated that:
- the AUV returns to within 10m of the deployment hole
- the AUV can be recovered efficiently
- the search and recovery methods work
AUV survey goals
In order of priority:
- 1 calibration transect (North line)
- "Lawn mower" pattern of overlapping transects for 100m square
- Ridge transect
It is likely a survey will be performed in a grid pattern, with overlapping sonar swaths. The area covered will depend on time avialable and performance of the search and recovery.
