7.2. Method

In brief, a typical day involved working from camp about 20 to 25 km in either direction on successive days making measurements, then returning to camp. This removed the need to continually go through the time consuming process of setting up and pulling down camp every day. It also allowed us to travel lightly whilst making measurements; we only carried the science equipment and emergency survival equipment that included 2 Dome tents. A more detailed account of method is contained in the Immediate Science Report for the event

It is worth mentioning here the method used to navigate the traverse line. We used GPS equipment loaned from Alex Pyne (Victoria University). A Trimble Pathfinder Basic Plus unit was mounted onto a skidoo cowling with its antenna attached to the back railing (see Section 5). Navigation with such a set-up is accurate to around ±100m. Such accuracy seemed adequate for our navigation purposes, since we had no difficulties finding fuel depots deployed earlier by the Twin Otter. For scientific reasons, more accurate positioning was required at measurement sites and this was achieved using additional Trimble Pathfinder equipment set recording for approximately 15 minutes at each site, eventually to be differentially corrected to a continuously logging base station GPS back at camp. The base station data will in turn be differentially corrected with data provided by USGS surveyors at McMurdo. With this method, we should be able to determine measurement positions to within about a metre.

Whilst GPS is a convenient and relatively simple means of navigation and position finding, we found that discussions and advice from Dosli surveyor Perry Gilbert invaluable. In this sense, we believe that whilst it may appear GPS removes the need to supply survey assistance to science events, the need to have access to someone familiar with surveying techniques (both conventional and GPS) is still vital.