Location and generation of high accuracy survey control marks using

Abstract

A method for accurately determining the location of a pre-selected survey or construction mark, or for accurately identifying the survey position for a new mark with pre-selected location coordinates. A Satellite Positioning System (SPS), such as GPS or GLONASS, with at least two SPS stations (antennas and receiver/processors) is used to receive and analyze SPS signals from four or more SPS signal satellites. An SPS signal reference station is placed at a position with known location coordinates, which can be stationary or be known functions of time. An SPS signal roving station receives the location coordinates of the reference station and determines its own location coordinates relative to the reference station, using SPS differential positioning. The roving station is then moved to a pre-selected survey mark or position, either to locate that survey mark or to identify (by marking) a new survey position from pre-selected location coordinates. The reference station analyzes the satellite signals received and transmits this measurement information and the reference station location to the roving station. The roving station independently makes similar measurements using satellites signals it receives. The roving station can contain a data-base of pre-selected positions that are to be located, which may or may not have corresponding physical marks. A handheld survey controller incorporating a visual or audible display is attached to the roving station, which guides the user to one or more of the pre-determined positions. Suitable radio communication apparatus is provided to allow the reference receiver to broadcast information to the roving receiver, even if the roving receiver is not directly visible from the reference receiver.