Photogrammetric methods can now be used to produce survey maps that meet the standards of the American Land Title Association (ALTA). An example of such a service that Sidwell performed is Scott Air Force Base in Southern Illinois. As part of a plan to privatize the military housing there, Sidwell was contracted to secure aerial photography and collect planimetric data for an ALTA survey of the subject property immediately following construction of new housing units. Sidwell continues to utilize this technology to assist surveying of properties and other features on the earth’s surface.
Photo Control Surveys
On a given project Sidwell will use a licensed surveyor to collect ground control using photo identifiable location (ie sidewalk intersections off of an existing photo) or targets predetermined to view on the photograph. Usually out of plastic panels or even out of concrete.