Method for the simulation of LADAR sensor range data

• US 9,361,412 B1
• Filed: 05/02/2013
• Issued: 06/07/2016
• Est. Priority Date: 03/26/2012
• Status: Active Grant

• 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 Agriculture
• Inventors: Hilde, Jeffrey J.
• Primary Examiner(s): Rivas, Omar Fernandez
• Assistant Examiner(s): Khan, Iftekhar
• Application Number:
  US13/886,060
• Time in Patent Office: 1,132 Days
• Field of Search: 703/2
• US Class Current: 1/1
• CPC Class Codes: G01S 17/89 for mapping or imaging
• CPC Class Codes: G06F 30/20 Design optimisation, verification or simulation optimisation, verification or simulation of circuit designs G06F30/30

Abstract

A method for simulating sensor range data includes providing a pulse model configured to generate a sequence of discrete energy pulses. A sequences of flashes associated with the pulse model are electronically generated. Each flash in the sequence of flashes has at least one range value. A sequence of scans is electronically generated from the sequence of flashes. Each scan in the sequence of scans has at least one flash. The sequences of scans is a simulation of sensor range data. The simulation of sensor range data is output in a tangible medium.

Claims

1. A method for simulating sensor range data using a non-transitory computer-readable medium, comprising:

providing an actual sensor associated with a navigation unit, and a virtual sensor associated with a graphics processing unit, wherein said actual sensor is defined in an actual three-dimensional space frame of reference;

receiving a pulse model configuration with said virtual sensor, wherein said pulse model configuration defines the parameters for said virtual sensor, wherein said pulse model is defined in three-dimensional space frame of reference;

electronically initializing said pulse model configuration by generating an initial discrete energy pulse at time t, according to the parameters for said virtual sensor, wherein the energy transmitted by said pulse model configuration is in the same direction as said actual sensor'"'"'s transmitted pulse defined in three-dimensional space frame of reference;

receiving a scene model configuration with said virtual sensor, and electronically initializing said scene model configuration using the three-dimensional space frame of reference of said pulse model configuration, wherein said scene model configuration is defined by a set of points, lines connecting said set of points, said lines forming a collection of triangles;

receiving an actual pulse from said actual sensor with said navigation unit, wherein said actual pulse is defined by a time, location, and orientation in a three-dimensional x, y, z, space frame of reference of said scene model configuration;

receiving scene location and orientation of land, sea, air, and objects composing said scene model, including the pose of the scene target model in the scene coordinate frame of reference;

electronically generating a hidden surface removal z-buffer using said scene model associated with time t from said scene model and said pulse position and orientation at time t from said pulse energy model, and initializing said hidden surface removal z-buffer to an initial value; and

electronically transforming said hidden surface removal z-buffer data into range data values defining a simulated range image.

2. The method according to claim 1, wherein said electronically transforming said hidden surface removal z-buffer data task, comprises:

receiving pulse intensity (P_r,c(t)) as a function of time (t) and view angle (r,c), where t=0 for the leading edge of the pulse as it leaves the sensor and where the view angle is for each hidden surface removal z-buffer element row (r) and column (c);

receiving an energy focusing optics (O_i,r,c) scaling factor as a function of view angle (r,c) for each sensor detector timing element (i);

computing the time (T_r,c) for the leading edge of the laser energy pulse to travel from the sensor, arrive at the Scene surface and return to the sensor for each hidden surface removal z-buffer row (r) and column (c) element;

generating a pulse energy scaling factor based on scene reflection, energy divergence with distance and atmospheric attenuation (S_r,c) for each row (r) and column (c) element of the scene;

computing a pulse energy wave form W_i(t) impinging on each sensor detector timing element (i) as a function of time (t), wherein

3. The method according to claim 1, further comprising outputting said simulated range image in a tangible medium.

4. The method according to claim 3, wherein said tangible medium is a visual display screen.

5. A non-transitory computer readable medium having stored thereon a plurality of computer executable instructions for simulating sensor range data using an actual sensor associated with a navigation unit and a virtual sensor associated with a graphics processing unit, wherein said actual sensor is defined in an actual three-dimensional space frame of reference, that, when executed by a computer including said graphics processing unit, causes the computer to:

receive a pulse model configuration with said virtual sensor, wherein said pulse model configuration defines the parameters for said virtual sensor, wherein said pulse model is defined in three-dimensional space frame of reference;

initialize said pulse model configuration by generating an initial discrete energy pulse at time t, according to the parameters for said virtual sensor, wherein the energy transmitted by said pulse model configuration is in the same direction as said actual sensor'"'"'s transmitted pulse defined in three-dimensional space frame of reference;

receive a scene model configuration with said virtual sensor, and electronically initialize said scene model configuration using the three-dimensional space frame of reference of said pulse model configuration, wherein said scene model configuration is defined by a set of points, lines connecting said set of points, said lines forming a collection of triangles;

receive an actual pulse from said actual sensor with said navigation unit, wherein said actual pulse is defined in an x, y, z, location and orientation in the three-dimensional space frame of reference of said scene model configuration;

receive scene location and orientation of land, sea, air, and objects composing said scene model, including the pose of the scene target model in the scene coordinate frame of reference;

generate a hidden surface removal z-buffer using said scene model associated with time t from said scene model and said pulse position and orientation at time t from said pulse energy model, and initializing said hidden surface removal z-buffer to an initial value; and

transform said hidden surface removal z-buffer data into range data values defining a simulated range image.

6. The non-transitory computer-readable medium according to claim 5, wherein said electronically transforming said hidden surface removal z-buffer data task, comprises:

receiving pulse intensity (P_r,c(t)) as a function of time (t) and view angle (r,c), where t=0 for the leading edge of the pulse as it leaves the sensor and where the view angle is for each Hidden surface removal z-buffer element row (r) and column (c);

receiving an energy focusing optics (O_i,r,c) scaling factor as a function of view angle (r,c) for each sensor detector timing element (i);

computing the time (T_r,c) for the leading edge of the laser energy pulse to travel from the sensor, arrive at the Scene surface and return to the sensor for each Hidden surface removal z-buffer row (r) and column (c) depth element, by taking two times the depth divided by the pulse velocity;

generating a pulse energy scaling factor based on scene reflection, energy divergence with distance and atmospheric attenuation (S_r,c) for each row (r) and column (c) element of the scene;

computing a pulse energy wave form W_i(t) impinging on each sensor detector timing element (i) as a function of time (t), wherein

7. The non-transitory computer readable medium according to claim 5, further comprising outputting said simulated range image in a tangible medium.

8. The non-transitory computer readable medium according to claim 7, wherein said tangible medium is a visual display screen.