Pegging out
Ahead of the data acquisition, surveyors accompanied by an ecologist and an agricultural liaison officer walk the survey area to determine the precise placement of receivers and energy sources. Walking the land gives us an accurate record of the condition of the land to ensure it is restored appropriately once operations are finished. It also identifies stand-off distances from buildings, buried utilities, hedges, trees, nesting birds, environmental and other restrictions, and determines whether the energy source at each location should be created by a group of up to three vibroseis machines (each about the size of a bin lorry) or in a small number of cases, by setting off a small charge buried up to ten metres below ground.