Horizontal control station marks indicate what information is determined?

Horizontal control station marks indicate what information is determined?

• A. Latitude and longitude have been determined
• B. Elevation only
• C. Depth of water
• D. Magnetic declination

Answer: (B)

Horizontal control marks define where a point sits on the surface in terms of its planimetric position. They establish precise coordinates on the map, usually latitude and longitude or a planar x,y system, so the point’s horizontal location is fixed. Elevation, the height above a reference level, is determined by vertical control marks rather than horizontal ones. So a horizontal control mark tells you that the horizontal coordinates have been determined, not the height. That’s why these marks are about where things are on the surface, while elevation, depth, and magnetic declination relate to vertical position or separate measurements.