Use of survey ropes, with meter marks indicated, to guide placement of instruments during an area survey.

Area surveys are performed by subdividing a region into square or rectangular grids that usually measure from 10 x 10 m to 30 x 30 m or larger. The area is then surveyed grid-by-grid. The corners of each grid should be established off fixed baselines within a site using surveying equipment like a theodolite or EDM in order to ensure a framework for a spatially accurate geophysical survey. Each grid should also possess coordinate ranges with a cartesian space (see grids in area surveys).

Within a grid, although commercially produced meter tapes might be employed to set up traverse lines, their metallic components can produce unwanted artifacts in the data with instruments sensitive to metals (e.g., EM, magnetometry), and they are expensive. More commonly, the traverse lines of each grid are established by staking a series of ropes parallel to each other on the ground. The length of each rope is equal to the grid size and each possesses meter marks through its length. Meter marks insure that each measurement is correctly located spatially in order that identified anomalies can be accurately mapped. The stakes should be non-metallic, either of plastic or wood, because of the sensitivity of many instruments to metals. The ropes might be placed 1-2 m apart to guide the traverses of the grid. The geophysical instruments are then moved along each rope where measurements, or samples, are recorded in meter or sub-meter increments. Although guide ropes might be placed 2 m apart the traverse separation might be set at only 0.5 m. It is, nevertheless, possible to place the instrument within 5-10 cm of its intended position while acquiring data (usually regarded as sufficiently accurate in archeo-geophysical surveys) by "eye-balling" meter marks to the right or left.

After survey of a grid, another is established, often adjacent to the previous, where survey commences again.

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