What is BACK SIGHT and FORESIGHT?

Back Sight(BS): The first staff reading taken by the surveyor after the levelling instrument is set up and levelled. B.S is generally taken on the point of known reduced level as on the benchmark or a change point. Fore sight (FS): The last staff reading taken before changing the instrument to the other position.#surveying #survey #totalstation #engineering #construction #civilengineering #landsurvey #civil #surveyengineering #sight #backsight #foresight #benchmark #leveling #BDA #IEA #COA #aecearth #swifterzacademy #swifterz