Surveyors prepare maps of sites before new construction, or improvements, are designed and built. This type of map is referred to as a topographic survey and is vital for the design professionals to know where to place the improvements for maximum benefit and proper water runoff. A topographic survey requires the collection of field data by electronic laser measurement and/or GPS technology. The data is converted to coordinates so that each measurement, or shot, has an exact horizontal and vertical location. The coordinates are processed, usually with a CAD (computer-aided drafting) program, to create an accurate visual and digital representation of the site. The use of CAD has made the sharing of information between design professionals (surveyors, architects, and engineers) very easy.