To ensure practical use, the relationship between a topographical map and the real world must be clear and accurate. For this reason, information such as scale, orientation and height must be known w.r.t standard reference points. A Survey Control determines the position (latitude, longitude and height) of features that can be seen on the map.
Modern maps are mostly developed from overlapped images taken from aircrafts (aerial photography) or digital images obtained from satellites (satellite imagery). A Survey Control not only scales and orients these maps, but also removes any distortions retained in the imagery.
Marvel offers the following Control Surveys for your geospatial needs:
- Horizontal Corridor Control Surveys
- Horizontal Project Control Surveys
- Vertical Project Control Surveys
- Supplemental Control