Patents by Inventor Christian Grässer

Christian Grässer has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Publication number: 20120013736
    Abstract: An apparatus for determining an azimuth of a target point is provided. The apparatus includes a support structure and an imaging device coupled to the support structure and configured to provide image data. The apparatus also includes a position measuring device coupled to the support structure and configured to determine position information and a processor in electrical communication with the imaging device and the position measuring device. The processor is configured to receive the image data from the imaging device, receive the position information from the position measuring device, determine a baseline between a first position and a second position, determine an orientation between overlapping images, and compute the azimuth of the target point relative to the baseline.
    Type: Application
    Filed: January 8, 2010
    Publication date: January 19, 2012
    Applicant: Trimble Navigation Limited
    Inventor: Christian Graesser
  • Patent number: 7930835
    Abstract: A method for aiming a surveying instrument towards a selected target is disclosed. The method includes, in at least one embodiment, capturing an image using a camera in the surveying instrument; selecting a target by identifying an object point in the image captured by the surveying instrument; calculating first horizontal and vertical rotation angles based on the object point identified in the image; rotating the surveying instrument over the first horizontal and vertical rotation angles to an intermediate line of sight; measuring a distance to a point along the intermediate line of sight; and calculating second horizontal and vertical rotation angles based on the object point in the image and on the measured distance. In at least one embodiment, the method may be implemented using computer software, hardware, firmware or a combination thereof. There is also disclosed a surveying instrument in which at least one embodiment of the method is implemented.
    Type: Grant
    Filed: January 25, 2007
    Date of Patent: April 26, 2011
    Assignee: Trimble AB
    Inventors: Set Svanholm, Christian Grässer, Michael Vogel, Nick Mein
  • Publication number: 20110043620
    Abstract: A method is disclosed for determining coordinates of a target in relation to a surveying instrument wherein a first image is captured using a first camera in a first camera position and orientation, a target is selected by identifying at least one object point in the first image, and first image coordinates of the object point in the first image are measured. In at least one embodiment, a second image is captured using a second camera in a second camera position and orientation, the object point identified in the first image is identified in the second image, and second image coordinates of the object point in the second image are measured. Target coordinates of the target in relation to the rotation center of the surveying instrument are then determined based on the first camera position and orientation, the first image coordinates, the second camera position and orientation, the second image coordinates, and first and second camera calibration data.
    Type: Application
    Filed: February 29, 2008
    Publication date: February 24, 2011
    Inventors: Set Svanholm, Michael Vogel, Christian Grässer
  • Publication number: 20110023578
    Abstract: The present invention provides a method for calibrating a geodetic instrument, an instrument and a computer program product thereof. In the method and geodetic instrument of the present invention, a value of at least one parameter affecting the measurements made by the instrument is detected and compared with a predetermined threshold. On the basis of the comparison between the detected value and the predetermined threshold, the instrument aims at a reference target and a calibration is performed using the reference target. The present invention is advantageous in that the accuracy and reliability of the measurements performed by the instrument are increased. Further, the present invention is advantageous in that the requirements on mechanical stability are reduced.
    Type: Application
    Filed: February 29, 2008
    Publication date: February 3, 2011
    Inventor: Christian Grässer
  • Publication number: 20110007154
    Abstract: A method is disclosed for determining coordinates of a target in relation to a surveying instrument wherein a first image is captured using a camera in a first camera position and orientation, a target is selected by identifying an object point in the first image, and first image coordinates of the object point in the first image are measured. The surveying instrument is then rotated around the rotation center so that the camera is moved from the first camera position and orientation to a second camera position and orientation, while retaining the rotation center of the surveying instrument in a fixed position. A second image is captured using the camera in the second camera position and orientation, the object point identified in the first image is identified in the second image, and second image coordinates of the object point in the second image are measured.
    Type: Application
    Filed: February 12, 2008
    Publication date: January 13, 2011
    Inventors: Michael Vogel, Set Svanholm, Christian Grässer
  • Publication number: 20100088910
    Abstract: A method for aiming a surveying instrument towards a selected target is disclosed. The method includes, in at least one embodiment, capturing an image using a camera in the surveying instrument; selecting a target by identifying an object point in the image captured by the surveying instrument; calculating first horizontal and vertical rotation angles based on the object point identified in the image; rotating the surveying instrument over the first horizontal and vertical rotation angles to an intermediate line of sight; measuring a distance to a point along the intermediate line of sight; and calculating second horizontal and vertical rotation angles based on the object point in the image and on the measured distance. In at least one embodiment, the method may be implemented using computer software, hardware, firmware or a combination thereof. There is also disclosed a surveying instrument in which at least one embodiment of the method is implemented.
    Type: Application
    Filed: January 25, 2007
    Publication date: April 15, 2010
    Inventors: Set Svanholm, Christian Grässer, Michael Vogel, Nick Mein
  • Publication number: 20090220144
    Abstract: A method for determining, in relation to a surveying instrument, target coordinates of a point of interest, or target, identified in two images captured by a camera in the surveying instrument. The method comprises determining coordinates of the surveying instrument, capturing a first image using the camera in the first camera position; identifying, in the first image, an object point associated with the target; measuring first image coordinates of the object point in the first image; rotating the surveying instrument around the horizontal axis and the vertical axis in order to position the camera in a second camera position; capturing a second image using the camera in the second camera position; identifying, in the second image, the object point identified in the first image; measuring second image coordinates of the object point in the second image; and determining the coordinates of the target in relation to the surveying instrument.
    Type: Application
    Filed: January 30, 2009
    Publication date: September 3, 2009
    Applicant: Trimble AB
    Inventors: Nick Mein, Set Svanholm, Christian Graesser, Michael Vogel
  • Patent number: 7382444
    Abstract: The invention relates to an electronic distance measuring apparatus for surveying, e.g. for measuring the distance from the apparatus to an object. The apparatus comprises: a) an objective lens (101), defining an optical axis (OA), b) at least two sources (111, 112) of structured light for transmitting beams (?1, ?2) of separate wavelengths towards said object, said beams on reflection from said object received by the objective lens (101), (c) at least two receivers (141, 142) arranged outside a beam path (109) as defined by the objective lens (101), and adapted to receive said received beams (?1, ?2) of structured light.
    Type: Grant
    Filed: June 18, 2003
    Date of Patent: June 3, 2008
    Assignee: Trimble AB
    Inventors: Leif Andersson, Mikael Herzman, Christian Grässer, Rolf Richter
  • Patent number: 6657734
    Abstract: A setting out device comprises a rod which can be supported at a target point in the area surrounding a point to be set out, a reflector which is arranged on the rod for tachymetric detection of the target point, a unit provided at the rod for transmitting information to and receiving information from a tachymeter, and an auxiliary setting out device which is arranged or can be arranged in a definite position in relation to the reflector for converting position correction information with respect to the point to be set out that was transmitted to the transmitting and receiving unit into a mark in the terrain representing the point to be set out. In this way, it is possible to set out possible projected points in the terrain within a short period of time and with great accuracy.
    Type: Grant
    Filed: August 31, 2001
    Date of Patent: December 2, 2003
    Assignee: ZSP Geodaetische Systeme GbmH
    Inventors: Ludwin-Heinz Monz, Bernd Donath, Wieland Feist, Christian Graesser, Steffen Laabs
  • Patent number: 6411372
    Abstract: A geodetic instrument is disclosed which is set up over a ground point by a tripod and whose telescope is swivelable about a tilt axis and a rotational axis and which is outfitted with a laser arrangement for centering the rotational axis over the ground point and for determining the height h of the intersection point of the tilt axis and rotational axis over the ground point. In an instrument of the type mentioned above, a first, preferably collimated, laser beam extending in the rotational axis and at least one further laser beam path which extends divergent to the first laser beam are provided and, together, enclose an angle &ggr;, and wherein there is further provided a measuring device for determining the distance a between the two laser beam paths at the height of the ground point and an evaluating device for calculating the height h of the intersection point over the ground point from the relationship h˜a.
    Type: Grant
    Filed: August 28, 2000
    Date of Patent: June 25, 2002
    Assignee: ZSP Geodaetische Systeme GmbH
    Inventors: Bernd Donath, Wieland Feist, Christian Graesser, Ludwin-Heinz Monz