Pole (surveying)

A surveying pole, also commonly referred to as a surveyor's pole, leveling rod, range pole, or sight pole, is a straight rod or staff, typically made of wood, metal, or fiberglass, used in surveying and land measurement. Its primary purpose is to establish a vertical line of sight and to mark specific points on the ground.

Surveying poles are often painted with alternating bands of bright colors, such as red and white or black and white, to enhance their visibility, particularly over long distances or in conditions with poor lighting. These color bands are usually measured in consistent increments, such as feet or meters, which can aid in estimating distances or heights.

These poles are employed in a variety of surveying tasks, including:

• Establishing lines: Poles are set up at key points to define a straight line between two locations. Surveyors use instruments like transits or total stations to sight along the pole to ensure accuracy.

• Measuring distances: While not a direct measurement tool, the consistent banding allows for rough distance estimations, particularly when used in conjunction with other instruments.

• Determining elevations: When used as a leveling rod in conjunction with a level (instrument), a surveying pole allows the surveyor to determine the difference in elevation between two points. Special leveling rods, which are designed for precise height measurements, are more common for leveling work than simple range poles.

• Marking locations: A surveying pole can be used to permanently or temporarily mark a specific point on the ground.

• Guiding construction activities: In construction, surveying poles can be used to guide the placement of structures or utilities along a pre-determined alignment.

The height of a surveying pole varies depending on the application and the terrain. Common lengths range from 6 to 12 feet (approximately 2 to 4 meters). Heavier-duty poles may incorporate a pointed metal tip for easy insertion into the ground, while others have a flat base for stability on hard surfaces. Modern surveyor's poles often feature screw-together sections for ease of transport and storage.