Remote wind turbulence sensing

Patent metadata

Field	Value
Publication number	US-10114035-B2
Application number	US-201514978934-A
Country	US
Kind code	B2
Filing date	Dec 22, 2015
Priority date	Jan 8, 2015
Publication date	Oct 30, 2018
Grant date	Oct 30, 2018

Abstract

Systems and methods for detection of atmospheric conditions using optical orbital angular momentum (OAM)-based spectroscopy include applying OAM states to a light beam to generate an OAM spectrum, transmitting OAM light beams into an atmosphere, and determining degradation of the generated OAM light beams passing through atmospheric turbulence. A rotation rate of aerosols in the atmosphere is determined by analyzing different frequency shifts in OAM states of OAM light beams. A reflected OAM spectrum including a plurality of OAM light beams associated with the aerosols in the atmosphere may be received, and Doppler frequency shifts caused by reflection off the aerosols in the atmosphere may be measured. Laguerre-Gaussian (LG) modes of the received light beams may be detected and sorted based on the OAM states of the LG modes, and wind turbulence values are predicted by analyzing a difference in the Doppler frequency shifts for the received OAM light beams.

First claim

What is claimed is:

1. A transmitter using optical orbital angular momentum (OAM)-based spectroscopy for detection of atmospheric conditions, comprising:
at least one OAM generator configured to apply at least one OAM state on a light beam to generate an optical OAM spectrum including a plurality of OAM states;
a transmitting device configured to send one or more generated OAM light beams into an atmosphere; and
one or more measurement devices configured to:
determine degradation of the generated OAM light beams when passing through atmospheric turbulence; and
determine a rotation rate of aerosols in the atmosphere by analyzing different frequency shifts in the plurality of OAM states.

2. The transmitter as recited in claim 1 , wherein the OAM spectrum is generated by crossing a spiral phase plate with the light beam.

3. The transmitter as recited in claim 1 , wherein the light beam is a Light Detection and Ranging (LIDAR) beam.

4. The transmitter as recited in claim 1 , further comprising an OAM multiplexer configured distinguish between a plurality of different orthogonal signals based on an orbital angular momentum of the OAM spectrum.

5. The transmitter as recited in claim 1 , wherein the OAM light beams are vortex beams with helical phase-fronts.

6. The transmitter as recited in claim 1 , wherein the at least one OAM generator is further configured to measure a set of OAM modes associated with a reflected optical OAM spectrum of the remote object.

7. A receiver using optical orbital angular momentum (OAM)-based spectroscopy for detection of atmospheric conditions, comprising:
a measurement device for determining Doppler frequency shifts caused by reflection off aerosols in an atmosphere for a plurality of received light beams with OAM states;
an OAM sorter to detect and sort a plurality of orthogonally decoded Laguerre-Gaussian (LG) modes of the plurality of received light beams based on the OAM states of the LG modes;
an analysis device for generating predictions of three-dimensional wind turbulence values by analyzing a difference in the Doppler frequency shifts for the plurality of received light beams with OAM states.

8. The receiver as recited in claim 7 , wherein the plurality of received light beams are Light Detection and Ranging (LIDAR) beams.

9. The receiver as recited in claim 7 , wherein the predicted three-dimensional wind turbulence values are employed to predict wind shear, down burst, and clear air turbulence.

10. The receiver as recited in claim 7 , further comprising determining a spatial profile change of the received light beams caused by wind turbulence to remotely sense a transverse velocity of the aerosols.

11. The receiver as recited in claim 7 , wherein the receiver is a heterodyne receiver.

12. The receiver as recited in claim 7 , wherein the Doppler frequency shifts are directly proportional to a line-of-sight velocity of wind.

13. The receiver as recited in claim 7 , wherein the receiver is further configured to distinguish single scattering from multiple scattering in turbid environments utilizing different OAM states by spatial coherency filtering of background light.

14. A method for using optical orbital angular momentum (OAM)-based spectroscopy for detection of atmospheric conditions, comprising:
applying at least one OAM state on a light beam to generate an optical OAM spectrum;
transmitting one or more generated OAM light beams into an atmosphere;
determining degradation of the generated OAM light beams when passing through atmospheric turbulence;
determining a rotation rate of aerosols in the atmosphere by analyzing different frequency shifts in a plurality of OAM states of the generated OAM light beams;
receiving a reflected OAM spectrum including a plurality of OAM light beams associated with the aerosols in the atmosphere;
measuring Doppler frequency shifts caused by reflection off the aerosols in the atmosphere for each of the generated OAM light beams in the OAM spectrum;
detecting and sorting a plurality of orthogonally decoded Laguerre-Gaussian (LG) modes of a plurality of received light beams based on the OAM states of the LG modes; and
predicting three-dimensional wind turbulence values by analyzing a difference in the Doppler frequency shifts for the plurality of received OAM light beams.

15. The method as recited in claim 14 , wherein the plurality of received light beams are Light Detection and Ranging (LIDAR) beams.

16. The method as recited in claim 14 , further comprising determining a spatial profile change of the plurality of received light beams caused by wind turbulence to remotely sense a transverse velocity of the aerosols.

17. The method as recited in claim 14 , wherein the optical OAM spectrum is generated by crossing a spiral phase plate with the light beam.

18. The method as recited in claim 14 , further comprising distinguishing between a plurality of different orthogonal signals based on an orbital angular momentum of the optical OAM spectrum.

19. The method as recited in claim 14 , wherein the plurality of OAM light beams are vortex beams with helical phase-fronts.

20. The method as recited in claim 14 , further comprising predicting wind shear, down burst, and clear air turbulence using the predicted three-dimensional wind turbulence values.

Assignees

• Nec Lab America Inc
• Nec Corp

Inventors

• Wang Ting
• Weng Yi

Classifications

• G01W1/10

  Devices for predicting weather conditions (computers per se G06; display devices G09) · CPC title

• B64D45/00

  Aircraft indicators or protectors not otherwise provided for · CPC title

• B64D2045/007

  Indicators or signs in the cabin, e.g. exit signs or seat numbering · CPC title

• G01S17/95 Primary

  for meteorological use · CPC title

• G01S7/4802

  using analysis of echo signal for target characterisation; Target signature; Target cross-section · CPC title