Topographical Surveys This service quickly collects detailed and accurate topographical data. The use of topographical surveys within archaeology are an effective method of recording the extent and shape of archaeological features. The technique accurately records earthen monuments by record, where the topography, if appreciable, can be mapped, often prior to excavation. This record aids landscape understanding and future archaeological interpretations. Discrete, potentially unrecorded features, with a low topographical profile can also be revealed. By taking a series of closely spaced measurements, over a defined area, a detailed topographical map can illustrate minute variations in the ground surface. For example, where a low topographical profile monument, such as a barrow, lies beneath a masking cover of vegetation, topographical surveys in effect can strip off the vegetation to reveal the underlying monument and previously unseen detail or elements associated with it. These changes can highlight the location of buried archaeological remains and reveal changes in elevation that could affect archaeological use or future construction plans. Earthsound offers differential Global Positioning System survey (DGPS) and total station surveys. These allow us to undertake topographical surveys in a range of different circumstances and locations facilitating all archaeological needs. Datasets such as aerial photographs, construction and excavation layouts can be overlaid on the topographical data, aiding understanding of the landscape. Geophysical and Geochemical data can also be overlaid with topographical data, providing an interactive element between topographical and geophysical anomalies. Topographical data can be displayed in a variety of graphical formats including a Digital Elevation Model (DEM) and a Digital Terrain Model (DTM). The DEM of a fulachta fiadh presents data in a 3-dimensional wire mesh, x, y and z coordinates are displayed as national grid easting, northing and elevation above sea level. The viewing angle of the DEM can be altered in a horizontal or vertical plane to highlight different elements/features.   The DTM of the same fulachta fiadh combines two graphical display options; a colourscale plot and a 3-D wire mesh (DEM). The colourscale plot presents data as pixels on a linear colour shaded scale. By combining the two plotting styles, the topographical data can be viewed as a digital terrain model, adding a colour reference to emphasise the data. The presence of an artificial light source can also vary the perception of data, creating shadows in depressions for example. Topographical Data Collection Two different types of topographical data collection methodologies can be used; coarse sample interval surveys and high resolution detailed survey. Coarse Sample Survey A coarse sample interval will provide data indicating broad topographical trends of a particular site or number of sites. Generally used for large-scale topographical surveys using a wide survey interval, this type of assessment enables the contours of an area to be mapped, aiding construction plans and viability surveys. High Resolution Survey or Micro-Topography A detailed survey methodology captures data at regular closely spaced sampling intervals, providing high resolution of earthworks, archaeological sites and local site topography. Survey Requirements If you would like to contact us to discuss your requirements so that we can develop a project plan and quotation, it would be useful to have the following information: Size and shape of survey area Purpose of survey Survey location Ground conditions - pasture, crop etc Other useful information includes map of the site, the location of any structures or field boundaries in the survey area Contact Details Earthsound Archaeological Geophysics Prospect House Drumagh Claremorris County Mayo Ireland Tel: +353 (0) 94 936 2228 | Archaeological Geophysics & Geochemistry | Geological Surveys | Environmental Surveys | Topographical Surveys | GPS Setting Out | Waterborne Surveys | Cultural Resource Management | Digital Graphics | Research & Development | Publications & Presentations | Education & Training | Project Management |