Patent ID: 6384902
Filing Date: 2002-05-07
Classification: G01C

Abstract:
A surveying apparatus comprising a reflector, a theodolite and a height determination device for determining the vertical distance between a reference point on the ground and the theodolite positioned vertically above the reference point, the reflector is arranged at the reference point having a greater reflectivity in an upward direction than the environment of the reflector, the theodolite comprising:a telescope, rotatable about a horizontal axis of the theodolite by a tilt angle; a distance measuring device attached to the telescope for measuring the distance between the telescope and the reflector by emitting a light beam in a direction corresponding to the tilt angle and by receiving light reflected by the reflector; and an angle-of-tilt encoder for measuring the tilt angle; the height determination device comprising: optical means for deflecting the emitted light beam in a downward direction towards the reflector and for expanding the divergence of the light beam at least in a direction perpendicular to the horizontal axis; and a front attachment for removably positioning the optical means at a predetermined distance in front of the telescope; the theodolite further comprising a processor-assisted evaluation device attached to the angle-of-tilt-encoder and the distance measuring device for determining the vertical distance.