Patent ID: 6369755
Filing Date: 2002-04-09
Classification: G01C,G01S

Abstract:
Apparatus for improved accuracy in measuring survey parameters, the apparatus comprising:a first station comprising: a first Satellite Positioning System (SATPS) antenna and first SATPS receiver/processor, connected together, for receiving SATPS signals from two or more in-view SATPS satellites, for measuring at least one of a pseudorange value and a carrier phase value of the first station relative to each of the in-view satellites from the SATPS signals received from each selected in-view satellite, and for determining location of the first station from the SATPS signals received; and an electronic distance meter, whose spatial orientation can be varied arbitrarily, connected to the first SATPS receiver/processor, for transmitting electromagnetic waves having at least one selected wavelength and for determining the distance from the first station to a selected object that is spaced apart from the first station by receipt of a return electromagnetic signal from the object, for determining the elevation difference between the first station and the object, and for determining an angular displacement between a line extending between the first station and the object and a selected reference line lying in a plane containing the first station; and a second station, spaced apart from the first station and comprising: a second SATPS antenna and second SATPS receiver/processor, connected together, for receiving SATPS signals from the in-view satellites, and for measuring at least one of a pseudorange value and a carrier phase value of the second station relative to each selected satellite; and an electronic distance meter responder with at least one electromagnetic wave retro-reflector that receives an incident electromagnetic wave from the first station and returns a return electromagnetic wave toward the first station in a direction approximately parallel to the direction from which the incident wave was received from the first station; where at least one of the first station and the second station has a vertical axis sensing mechanism for sensing the direction of a substantially locally vertical axis, to assist in determining the elevation difference; where at least one of the first station and the second station has a supplementary communications mechanism for transmitting the at least one pseudorange value or carrier phase value measured at the first station or at the second station, respectively; and a third station, acting as a reference measurement unit for the survey, where the third station is provided with at least one of a known pseudorange value and a known carrier phase value of the third station relative to each in-view satellite, the third station comprising: a third SATPS antenna and third SATPS receiver/processor, connected together, for receiving SATPS signals from the in-view SATPS satellites, for measuring at least one of a pseudorange value and a carrier phase value of the third station relative to each in-view satellite, and for computing at least one of (1) a pseudorange difference between the measured pseudorange value and the known pseudorange value for each selected satellite and (2) a carrier phase difference between the measured carrier phase value and the known carrier phase value for each selected satellite; and a third station communications mechanism, connected to the third SATPS receiver/processor, for receiving the at least one of the pseudorange value and the carrier phase value transmitted by the at least one of the first station and the second station, and for using the received at least one pseudorange value and carrier phase value, together with the at least one pseudorange difference and carrier phase difference for a corresponding selected satellite, to compute at least one of a corrected pseudorange value and a corrected carrier phase value for the at least one of the first station and the second station, wherein said third station and at least one of said first station and said second station have at least two in-view SATPS satellites in common, and said third station determines at least one of a corrected first station location and a corrected second station location, using said at least one of pseudorange value and carrier phase value received from at least one of said first station and said second station.