Invention Grant
- Patent Title: System method and apparatus for optical directional determination
- Patent Title (中): 用于光学定向测定的系统方法和装置
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Application No.: US12062492Application Date: 2008-04-03
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Publication No.: US07812950B2Publication Date: 2010-10-12
- Inventor: John P. Sharpe
- Applicant: John P. Sharpe
- Applicant Address: US CA San Luis Obispo
- Assignee: California Polytechnic State University Corporation
- Current Assignee: California Polytechnic State University Corporation
- Current Assignee Address: US CA San Luis Obispo
- Agency: Martine Penilla & Gencarella, LLP
- Main IPC: G01N21/00
- IPC: G01N21/00

Abstract:
A method for measuring the direction and velocity of a target in a measurement volume in a laser Doppler velocimetry system includes selecting a discrete number of grating positions for an electrically switchable grating, placing the electrically switchable grating in a light path of a laser source. The laser source outputs a laser beam along the light path. The method further includes switching the electrically switchable grating sequentially through the discrete number of grating positions at a grating frequency to generate diffracted light beams from the laser, directing the diffracted light beams through a lens, focusing the diffracted light beams on a measurement volume, passing a target through the measurement volume in a target direction at a target velocity and receiving scattered light in a detector and calculating the power spectrum of light intensity fluctuations. The power spectrum includes a maximum peak. The maximum peak occurs at a frequency shifted from the grating frequency an amount corresponding to the target velocity and in a direction corresponding to the target direction. A laser Doppler velocimetry system for measuring the direction and velocity of a target in a measurement volume is also disclosed.
Public/Granted literature
- US20090002705A1 SYSTEM METHOD AND APPARATUS FOR OPTICAL DIRECTIONAL DETERMINATION Public/Granted day:2009-01-01
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