Survey report 1998/99 summer season Voyage 4 Australian Antarctic Division Authors - R.Lemon / AUSLIG

Brief description

Taken from sections of the report:

Introduction
This report details the survey work carried out on Voyage 4 during November and December 1998 by LANDINFO on behalf of the Australian Antarctic Division's MAGIP Field Program. The principle aim of this work was to acquire aerial photography of penguin rookeries near Australia's three Antarctic Stations and to carry out survey work associated with the Antarctic Tide Gauge Network. A number of other tasks were also carried out. This report details each task carried out and the results achieved. The following people carried out the survey work:

Richard Lemon LANDINFO Pty Ltd
Roger Handsworth Antarctic Division Instrument Engineer

This report covers the fieldwork associated with the MAGIP Field Program. Some non survey aspects of the tide gauge work will be the subject of a separate report to be submitted by Roger Handsworth.

Time Frame
The survey party departed Hobart at 5:15pm on Thursday 29th October 1998 aboard the Aurora Australis on Voyage 4 of the 1998-99 summer season. The survey party arrived at Casey Station via helicopter from the Aurora Australis just before 12pm (UTC+8) on Saturday 7th November. After spending a period of about 25 hours at Casey the survey team returned to the Aurora Australis at about 1pm on Sunday 8th November 1998.

The Aurora Australis arrived off Davis Station on the morning of Wednesday 18th November 1998. The survey party had access to the station from about 2.30pm (UTC+7) the same day. The survey team had four full days in which to carry out its tasks at Davis. The Aurora Australis left Davis on the morning of Sunday 22nd November on route to Sansom Island. The survey party returned to the Aurora Australis by helicopter at about 7:30pm on Sunday 22nd November.

The survey party was flown to Sansom Island at about 9:30am on Monday 23rd November and returned to the Aurora Australis at about 3:30pm the same day.

Due to problems with Aurora Australis' propeller pitch control, the survey party was flown to Mawson Station by long range helicopter on Wednesday 2nd December and arrived at about 8:30am (UTC+6). The survey team had eight full days at Mawson station before departing for the Ship on Thursday 10th December at about 11am.

The Aurora Australis returned to Fremantle at about 11am Western Standard Time (UTC+8) on Monday 28th December 1998.

Project Outline
The Antarctic Division's Brief, which outlines the details of the program, is included in Appendix A. The program of work was divided into four specific sites, Casey, Davis, Mawson and Sansom Island. The work at each of the Antarctic stations was divided into two main areas of interest. These being the aerial photography of the penguin rookeries using the Linhof camera and survey work associated with the tide gauges and tide gauge bench marks. The work at Sansom Island involved the coordination of photo control points.

A list of the individual tasks and a summary of the achievements can be found at Appendix B.

Lineage

Progress Code: completed

Statement: See the report for further information.

The values provided in spatial coverage are approximate only.

AUSLIG is now known as Geoscience Australia.

Comments and Recommendations

Camera Equipment
All camera equipment should be fully checked and made operational prior to departure. Although a pre-season helicopter trial was carried out with the Zeiss camera, none was carried out with the Linhof. Several new cables had to be made or borrowed and the pilot's display needed repairing while on the voyage south. The wiring is relatively messy and complicated. A wiring harness would be less cluttered and help make the camera easier and faster to install in the helicopter.

The flight PC is dated and needs to be replaced. The backup battery in the existing PC failed prior to departure and the CMOS could no longer identify the hard drive. This rendered the PC useless for the duration of voyage 4 and LANDINFO's backup PC had to be used in its place.

Further consideration needs to be made into the suitability of the Linhof camera with the 180mm lens for penguin surveys. At a flying height of 1,000m the photo scale is about 1:5,500 and this is only barely suitable. A proposed increase in the flying height from 1,000m to 1,500m will clearly reduce the scale to a point that will render the photography useless for counting penguins. A better camera, longer lens and/or lower flying height need to be considered for future penguin surveys.

Flying Hours Available
There was some confusion within voyage management about the budget available for flying hours associated with the aerial photography of the penguin rookeries. This did cause some problems and it would be an advantage if this issue could be resolved prior to departure. Regardless of the problem however voyage management did give the aerial photography program its full support with every opportunity to fly being made available.

Locating the Tide Gauges
Many hours were wasted trying to locate the bottom mounted tide gauge moorings. Accurate coordinates or well-placed markers are required to locate the moorings. Early in the season when the ice is thick it is virtually impossible to locate the mooring unless the hole is drilled directly above the mooring. Even when found, in these conditions it would not be sensible to attempt to place a new gauge. The narrow field of view and poor light due to the thick ice makes the bottom impossible see. As a result there would be no way of knowing that the new gauge has been placed correctly in the mooring.

Once located, all mooring should be accurately located both by direct measurement and by the placement of markers on shore. If possible, the placement of new gauges or down loading of the gauges should be carried out while the ice is thick enough to safely stand on but thin enough to enable the bottom to be seen.

Tide Gauge Equipment
Due to the cold and salty environment the tide gauge PC's and interface units are starting to fail. At Mawson both interface units failed, one being repaired on station by Roger Handsworth and the other returned to Australia for repair. The PC's although adequate to the task are also beginning to fail. The battery will not hold a charge in the cold conditions and the cable connections are starting to corrode. To ensure it is possible to down load the gauges each year, the down loading equipment should be either replaced or regularly maintained.

Optical Magnetic Measurement Equipment
On a request by Bob Sutton, AGSO Geophysical Engineer, an inspection was made of the optical measurement equipment in the absolute magnetic hut. The general state of the equipment was found to be very poor and badly in need of servicing and re-calibrating.