Frequently Asked Questions
Q: How do I get descriptions for horizontal and vertical survey control stations?
A: The Survey and Right of Way section provides survey control descriptions at the Maine Horizontal and Vertical Control Points web page with control point descriptions.
Q: Someone is pounding a big rod in the ground on the road in front of my house. What are they doing?
A: This is generally a Survey Point Control Station. Normally, these stations are pounded flush into the ground.
Q: What do I do when I find a big white "X" on my front lawn?
A: Our MaineDOT GPS Field Crew strategically places temporary cloth or pavement painted white "X's" prior to aerial photography of a region in Maine. The photography is taken by an airplane at altitudes from 2500' to 12,000'. These targets are used to orient the photographs taken in order to match the photos to actual ground coordinates. After the marks are placed, GPS equipment is placed above the point to configure the point in the Maine State Coordinate System. Once the plane has flown the area, the temporary marks are then removed by the field crew.
Attempts to contact the land owner are made prior to placing these targets. Additionally, contact information is left by the target for the land owner with a date when the target is expected to be removed.
Q: How do I get authorization to obtain copies of aerial photos?
A: The Survey and Right of Way Section provides such authorization.
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