30 Nov - 20 Dec - Getting Ready to Roll
30 November: The team arrived at Rothera by BAS Dash-7 aircraft from the Falkland Islands.
2 December 2000: The aerial photography and global positioning survey (GPS) survey equipment arrived at Rothera on board the RRS James Clark Ross.
2-10 December: The early part of December was spent checking equipment and undertaking pre-deployment training.
Training developed skills needed for effective living and working in Antarctica, such as HF radio communications, skidoo maintenance and familiarisation with the medical equipment supplied to field parties. Preparation for overland travel included practising travelling as a roped skidoo and sledge unit, camp-craft using the BAS pyramid tents and extensive safety training. Safe travel in the field as a working pair of scientist and GA (field assistant and guide) requires competence in basic mountaineering and crevasse rescue techniques and these are practised in the Rothera local area prior to deep-field deployment.
11- 15 December: After completion of the pre-deployment training and a period of poor weather, the first field project was a ground survey in support of a new map of McCallum Pass, about 25 km from Rothera. The McCallum Pass glacier is the only route through the mountains from Rothera to the main part of Adelaide Island, but has many crevasses (cracks in the glacier surface, sometimes many metres wide and often snow covered) which make travel difficult. MAGIC will be producing a large-scale topographic map of the area, with an aerial photographic backdrop to show the positions of the crevasses, as an aid to safer travel. The position of the crevasses changes over time with flow of the glacier, but once the initial survey is in place the map can be updated with new aerial photography acquired in future years.
GPS surveying, where satellites are used to calculate the position of a receiver to an accuracy of a few centimetres, was used to calculate the geographic positions of either conspicuous rock outcrops, or locations where high-visibility targets will be laid on the snow prior to the aerial photography sortie. These surveyed points can then be used to tie the aerial photographs to their ground positions. Aerial photography for the project will be acquired later in the field season when the crevasses are more clearly visible from the air.
16-17 December: Finalising flight plans for the aerial photography programme.
Aerial photography is required for both future topographic mapping work and in support of current BAS science projects. BAS field scientists, particularly geologists and terrestrial biologists, use aerial photography as a reconnaissance tool for selecting sites for future field visits, planning safe access routes and even assessing the geology of inaccessible areas. Aerial photography targets this season stretch from Brabant Island (64°15'S) to the Behrendt mountains in Ellsworth Land (75°30'S).
18-20 December: Installing and testing the aerial photography equipment.
The equipment consists of:
- A motorised mounting ring which keeps the camera level independently of the attitude of the aircraft and corrects for any side-drift in the flight track.
- The camera body and lens cone.
- A film magazine which holds 80 m of 23 cm wide aerial photography film.
- A navigation telescope which looks forwards and down and allows the operator to give the pilot instructions to follow the required path, expose the camera at the correct interval between photographs and control the drift correction applied by the mounting ring.
The equipment weighs about 135 kg in total. The navigation sight is mounted at the front of the aircraft, just behind the cockpit and the camera points vertically down from a well in the aircraft floor near the rear doors.
The scale of the aerial photography is related to the flying height of the aircraft. Most projects require flying at the maximum practical height of 15,000 feet, for a photo-scale of 1;30,000. This means that absolutely cloudless weather conditions are required - a rare occurrence on the Antarctic Peninsula! Rothera receives meteorological satellite imagery daily and this is invaluable for identifying cloud-free target areas. Nevertheless, spells of waiting for suitable aerial photography weather are inevitable.
A short test flight was completed on 19 December and the team are now waiting for good weather to be able to continue.