SYSTEM AND METHOD FOR MONITORING OPTICAL SUBSYSTEM PERFORMANCE IN CLOUD LIDAR SYSTEMS

• US 20160025842A1
• Filed: 07/24/2014
• Published: 01/28/2016
• Est. Priority Date: 07/24/2014
• Status: Active Grant

• Current Assignee: Rosemount Aerospace, Inc. (Rtx Corporation)
• Original Assignee: Rosemount Aerospace, Inc. (Rtx Corporation)
• Inventors: Anderson, Kaare J., Ray, Mark D.
• Granted Patent: US 9,476,968 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G01M 11/00 Testing of optical apparatus; Testing structures by optical methods not otherwise provided for
• CPC Class Codes: G01S 17/95 for meteorological use
• CPC Class Codes: G01S 2007/4975 of sensor obstruction by, e.g. dirt- or ice-coating, e.g. by reflection measurement on front-screen
• CPC Class Codes: G01S 7/497 Means for monitoring or calibrating
• CPC Class Codes: G01S 7/4972 Alignment of sensor
• CPC Class Codes: Y02A 90/10 Information and communication technologies [ICT] supporting adaptation to climate change, e.g. for weather forecasting or climate simulation

Abstract

A method of detecting optical subsystem failures includes emitting a pulsed light beam from a laser through a window. A reflection signal indicative of a portion of the beam reflected by the window is compared to an expected signal to monitor for degradation of an optical component.

Claims

1. A method of detecting optical subsystem failures, comprising:

emitting a pulsed light beam from a laser through a window; and

comparing a reflection signal indicative of a portion of the beam reflected by the window to an expected signal to monitor for degradation of an optical component.

2. The method of claim 1, wherein emitting includes emitting the light beam at a predetermined frequency.

3. The method of claim 1, wherein comparing includes detecting laser degradation by comparing amplitude, pulse width and pulse frequency of a reflection signal received by a trigger photo diode to amplitude, pulse width and pulse frequency of the expected signal.

4. The method of claim 1, wherein comparing includes detecting transmitter optic misalignment by comparing amplitude of a reflection signal received by a trigger photo diode with amplitude of a reflection signal received by a photodetector measuring reflection off the window.

5. The method of claim 1, wherein comparing includes detecting transmitter optic misalignment by comparing amplitude of a reflection signal received by a trigger photo diode with amplitude of a reflection signal received by a receiver photodetector.

6. The method of claim 1, wherein comparing includes detecting window contamination by comparing amplitude of a reflection signal received by a photodetector measuring reflection off the window with amplitude of the expected signal.

7. The method of claim 1, wherein comparing includes detecting window contamination by comparing amplitude of a reflection signal received by a photodetector measuring reflection off the window with amplitude of a reflection signal received by a trigger photo diode.

8. The method of claim 1, wherein comparing includes detecting receiver optics misalignment and photodetector degradation by comparing amplitude of a reflection signal received by a receiver photodetector with amplitude of a reflection signal received by a trigger photo diode.

9. The method of claim 1, wherein the step of comparing includes detecting receiver optics misalignment and photodetector degradation by comparing amplitude of a reflection signal received by a receiver photodetector with amplitude of a reflection signal received by a photodetector measuring reflection off the window.

10. The method of claim 1, wherein the optical component is selected from the group consisting of transmitter optics, receiver optics, lasers and photodetectors.

11. A system comprising:

a laser;

a plurality of optical components; and

a processor operatively connected to a memory, wherein the memory includes instructions recorded thereon that, when read by the processor, cause the processor to;

compare a reflection signal indicative of a portion of a light beam emitted by the laser and reflected by a window to an expected signal to monitor for degradation of at least one optical component.

12. The system as recited in claim 11, wherein the memory includes instructions recorded thereon that, when read by the processor, cause the processor to:

detect laser degradation by comparing amplitude, pulse width and pulse frequency of a reflection signal received by a trigger photo diode to amplitude, pulse width and pulse frequency of the expected signal.

13. The system as recited in claim 11, wherein the memory includes instructions recorded thereon that, when read by the processor, cause the processor to:

detect transmitter optic misalignment by comparing amplitude of a reflection signal received by a trigger photo diode with amplitude of a reflection signal received by a photodetector measuring reflection off the window.

14. The system as recited in claim 11, wherein the memory includes instructions recorded thereon that, when read by the processor, cause the processor to:

detect receiver optics misalignment and photodetector degradation by comparing amplitude of a reflection signal received by a receiver photodetector with amplitude of a reflection signal received by a photodetector measuring reflection off the window.

15. The system as recited in claim 11, wherein the memory includes instructions recorded thereon that, when read by the processor, cause the processor to:

detect receiver optics misalignment and photodetector degradation by comparing amplitude of a reflection signal received by a receiver photodetector with amplitude of a reflection signal received by a trigger photo diode.