Lidar system

• US 8,896,818 B2
• Filed: 04/19/2010
• Issued: 11/25/2014
• Est. Priority Date: 09/22/2006
• Status: Active Grant

• Current Assignee: Leica Geosystems AG (Hexagon AB)
• Original Assignee: Leica Geosystems AG (Hexagon AB)
• Inventors: Walsh, Gregory C., Aindow, Alan
• Primary Examiner(s): RATCLIFFE, LUKE D
• Application Number:
  US12/763,123
• Publication Number:
  US 20110102764A1
• Time in Patent Office: 1,681 Days
• Field of Search: 356 301- 315, 356 401- 41, 356 501- 515, 356 6- 22, 356/28, 356/28.5, 35613901-1391
• US Class Current: 356/4.01
• CPC Class Codes: G01C 3/08 Use of electric radiation detectors
• CPC Class Codes: G01S 17/10 using transmission of interrupted, pulse-modulated waves determination of distance by phase measurements G01S17/32
• CPC Class Codes: G01S 17/87 Combinations of systems using electromagnetic waves other than radio waves
• CPC Class Codes: G01S 17/89 for mapping or imaging
• CPC Class Codes: G01S 7/4818 using optical fibres
• CPC Class Codes: G01S 7/483 Details of pulse systems
• CPC Class Codes: G01S 7/4865 Time delay measurement, e.g. time-of-flight measurement, time of arrival measurement or determining the exact position of a peak peak detection in noise, signal conditioning G01S7/487
• CPC Class Codes: G01S 7/497 Means for monitoring or calibrating

Abstract

Methods and systems for using spectrally separated light pulses to collect more LIDAR information are presented. In one embodiment, a monochromatic pulse is transmitted to collect range information and a white pulse is transmitted a short time afterwards to collect spectral responsivity information or color of the target. In another embodiment, the white light pulse is used to collect both range and spectral responsivity information of the target. In another embodiment, the spectral separated laser is spatially spread in order to collect range information over more than one point at a time.

Claims

1. A method of obtaining location information regarding an object, the method comprising:

generating a laser pulse;

dividing the laser pulse into a plurality of wavelength separated laser pulse portions;

simultaneously directing each of the wavelength separated laser pulse portions to the object at a different angular direction and detecting a corresponding plurality of reflected wavelength separated laser pulse portions; and

resolving the plurality of reflected wavelength separated laser pulse portions to generate location information regarding the object.

2. The method of claim 1, wherein the resolving step comprises providing the plurality of reflected wavelength separated laser pulse portions to separate detector channels, each detector channel being connected to corresponding timing circuitry for generating the location information.

3. The method of claim 1, wherein the resolving step comprises providing the plurality of wavelength separated laser pulse portions to separate detector channels and time multiplexing each channel using optical delay lines of different length, the optical delay lines being connected to timing circuitry for generating the location information.

4. A system for generating both location and spectral information for a plurality of points on an object, the system comprising:

a laser that emits pulses of light;

means for splitting each pulse of light into a plurality of pulse components of a respective plurality of wavelengths;

means for detecting the plurality of pulse components; and

means for resolving the plurality of pulse components that are associated with a single point on the object, wherein the means for resolving corresponds the pulse components to each other based upon a known time delay for each pulse component.

5. The system of claim 4, wherein the plurality of pulse components of a respective plurality of wavelengths are simultaneously directed to the object.

6. The system of claim 5, wherein each of the plurality of pulse components of a respective plurality of wavelengths simultaneously directed to the object at a different angular direction.

7. The system of claim 4, wherein the means for splitting each pulse of light into a plurality of pulse components comprises a beam splitter.

8. The system of claim 4, wherein the means for detecting the plurality of pulse components comprises a plurality of detector channels wherein each of the plurality of detector channels is configured to receive one of the plurality of pulse components.

9. The system of claim 8, wherein the means for resolving the plurality of pulse components comprises a multiple trigger timing electronic device configured to:

receive each of the plurality of pulse components from each of the plurality of detector channels, and

time-multiplexing the plurality of pulse components received from each of the plurality of detector channels using optical delay lines of different length, wherein the optical delay lines are connected to timing circuitry for generating the location information.