Sewer investigation vehicle has marker frame in camera field of view with marker heads creating laser light markings on wall for video imaging of deformations

摘要

A sewer (1) investigation vehicle (2) has a marker frame (19) in the camera (6) view (7) with two marker heads (12, 13) in a plane perpendicular to the sewer with marking laser creating point or strip markings on the wall for video investigation of the wall by imaging the projected markings (14-16).