Definition - What does Directional Survey mean?
A directional survey, in the context of Horizontal Directional Drilling, can be defined as a method of survey used to map out underground utilities such as sewer pipelines, water pipelines, gas pipelines and cables for planning purposes. Directional surveys map the planned underground route, taking into consideration soil type and any obstructions, for drilling using trenchless technology.
Trenchlesspedia explains Directional Survey
A directional survey is carried out with the aid of directional survey stations and GPS capabilities using mounted video cameras that enable viewing below the surface of the earth while taking coordinates to assist the drilling process. A surveying system is also located on the drill head that is controlled by an operator with a computer. The pilot drill bores a hole along the planned route while transmitting data back to the computer regarding its surroundings. Based on this data, the operator is able to control the speed and direction in which the drill bit advances. The use of surveying tools enables carrying out trenchless construction with minimum disturbance to surface conditions like traffic and natural habitats. A directional survey is essential as it helps map out the location for future reference and helps to reduce accidents, such as cross boring, that can prove to be dangerous.