Remote location determination system

• US 10,006,770 B2
• Filed: 01/30/2017
• Issued: 06/26/2018
• Est. Priority Date: 10/15/2012
• Status: Expired due to Fees

• Current Assignee: the united states of america as represented by the secretary of the navy
• Original Assignee: the united states of america as represented by the secretary of the navy
• Inventors: Hamilton, John
• Primary Examiner(s): Jeanglaude, Gertrude Arthur
• Application Number:
  US15/419,392
• Publication Number:
  US 20170138738A1
• Time in Patent Office: 512 Days
• Field of Search: 701 3, 701408, 701120, 701469
• CPC Class Codes: G01C 21/1652 with ranging devices, e.g. LIDAR or RADAR
• CPC Class Codes: G01S 19/14 specially adapted for specific applications
• CPC Class Codes: G01S 19/53 Determining attitude

Abstract

A remote geolocation system is provided including an inertial navigation unit (INU) having orthogonally disposed three axis accelerometers/gyroscopes in a strap down configuration in a case, a laser range finder (LRF) aligned with one INU axis, a GPS, and machine instructions that create a virtual INU (VINU) used to determine orientation of the case at an activation point (AP) when the LRF is pointed at a target, take sequences of global positioning satellites (GPS) location data and inertial measuring unit (IMU) orientation measurements from a starting location to the AP, draw a line between the starting location and the AP, identify a longitude line (LL) passing through the line, align one VINU axis with the LL, align another VINU axis with INU detected gravity, and align a remaining VINU axis with the LRF'"'"'s output at the AP.

Claims

1. A remote geolocation system, comprising:

a case comprising an inertial navigation unit (INU) having orthogonally disposed three axis accelerometers/gyroscopes in a strap down configuration in the case;

a laser range finder (LRF) aligned with one INU axis;

a global positioning satellite (GPS);

a display;

a processor configured to execute a plurality of Non-Transitory Machine Readable Instructions (NTMRI);

a storage medium storing the plurality of NTMRI that create a virtual INU (VINU) used to determine orientation of the case at an activation point (AP) when the LRF is pointed at a target, take a sequence of GPS location data and inertial measuring unit (IMU) orientation measurements from a starting location to the AP, draw a line between the starting location and the AP, identify a longitude line (LL) passing through the line, aligns one VINU axis with the LL, aligns another VINU axis with INU detected gravity, and aligns a remaining VINU axis with the LRF'"'"'s output at the AP, wherein the aligned VINU axis, GPS location at the AP, and LRF range data for the target is used to determine latitude, longitude, and elevation of the target.

2. A remote geolocation system, comprising an apparatus comprising a case that comprises an INU comprising an inertial navigation system (INS) or an IMU comprising three axis accelerometers and three axis gyroscopes in a strapped-down configuration in the case with one INU axis aligned with a laser output of the laser range finder and the three INU axis are disposed orthogonal with each other, the case further includes a GPS, a control system, and a machine readable recording medium storing a plurality of non-transitory machine readable instructions adapted to generate a VINU, determines an orientation of the IMU at a selected point with respect to the Earth based on position determinations using the GPS and IMU orientation data acquired at each said position determination along a displaced path which are used to determine true north data that is used to align one axis of a virtual IMU (VIMU), another VIMU axis is aligned with gravity based on IMU outputs, and another VIMU axis is aligned with the laser rangefinder when pointed at a target and activated, the plurality of non-transitory machine readable instructions further determine position of the target comprising latitude, longitude, and elevation when the laser range finder is activated based on the VIMU, the plurality of machine readable instructions further comprise an error determination module which determines an error value of the position of the target.

3. A system as in claim 2, wherein the location includes elevation of the apparatus at each point of the sequence of measurements.

4. A system as in claim 2, wherein the selected orientation of the apparatus at a desired point comprises a first point at which a predetermined accurate orientation value is determined.

5. A system as in claim 4, wherein the desired orientation is true north and the predetermined accuracy is less than five angular mil degrees accuracy.

6. A system as in claim 2, wherein the sequence of measurements can include at least two measurements along a path of travel which is not purely vertical in elevation.

7. A remote geolocation system comprising:

a case formed with a pointing alignment structure;

a laser range finder coupled with the case aligned with the pointing alignment structure;

a display disposed into the case that displays a plurality of graphical user interfaces;

an INU including an IMU placed into a strap down configuration within the case comprising three axis accelerometers, three axis gyroscopes, with an x-axis of the accelerometer and gyroscope axis aligned with the alignment structure and the laser range finder'"'"'s pointing axis;

a machine readable storage medium that stores a plurality of machine readable instructions;

a processor coupled within the case in communication with the INU and laser range finder (LRF) which is configured to read the plurality of machine readable instructions and data structures stored in the machine readable recording medium;

a control section including a trigger or control that receives an activation input from a user which activates the laser range finder to determine distance to a target when the user points the alignment structure at a target; and

a plurality of machine readable instructions comprising a first plurality of machine readable instructions that operates the INU, IMU and GPS;

a second plurality of machine readable instructions configured to generate a virtual INU including a three axis x, y, and z data model;

a third plurality of machine readable instructions that creates a three dimensional georeferenced map model comprising latitude and longitude information overlaid over terrain that the case is traversed over;

a fourth plurality of machine readable instructions that selectively starts recording latitude and longitude data of the case at a plurality of stored location points starting at an initial location point selected by the user using the control section or the graphical user interface along a displacement path that the user carrying the case passes over ending in a final location point;

a fifth plurality of machine readable instructions that receives a remote georeferenced determination activation from the control section or one of the graphical user interfaces which activates the laser rangefinder to obtain a target distance measurement between the case and the target at the final location point and determines a path line between the initial location point and the final location point then selects and stores a line of longitude from the map model which passes through the path line as a selected line of longitude data;

a sixth plurality of machine readable instructions that rotates the VINU via a rotational matrix so that it rotates the VINU axis data to rotate/align the VINU'"'"'s z axis based on inputs from the INU including z axis INU sensor output detecting gravity to rotate the VIMU'"'"'s x, y, and z to co-align respective z-axis;

a seventh plurality of machine readable instructions that rotates or aligns the VINU y axis with the with the selected line of longitude data;

an eighth plurality of machine readable instructions that aligns the x axis of the VINU with the laser range finder axis as it points at the target at the final location point;

a ninth plurality of machine readable instructions that remotely determines the target'"'"'s latitude, longitude and elevation based on target distance measurement, the final location point, and the virtual IMU'"'"'s three axis that has been aligned with detected gravity, the selected line of longitude, and the laser range finder'"'"'s axis that was pointing at the target at the final location point; and

an error determination module which determines an error value of the position of the target.