Most surveys start with research at the county courthouse to find records of plans and deeds associated with the area being surveyed, including surrounding properties. This provides a legal history of ownership and easements for who can use a property. The documented descriptions are later compared with the physical evidence found in the real world, such as iron pins, concrete monuments, stone walls, buildings and fences.
Local surveying begins by finding or setting known points to make it possible to relate the real world to the data collected, and to return to exactly the same place on a future day. Modern surveying then uses sophisticated “total station” and/or GPS equipment to measure points of interest. Each point of interest is given a unique number and a description of what is at that point. When the survey equipment “looks” at the point it internally knows the horizontal and vertical location of that point.
The points of interest are then downloaded to a computer and the surveyor creates a drawing that is a representation of what was seen in the real world. This drawing is like a map to a specific scale. Depending on what the drawing is used for, it will have varying amounts of detail. For a simple boundary survey it might only have a few points. For detailed topographic local surveying to design a roadway it might have many thousands of points that are then connected by lines and interpolated to create contours to represent elevations.