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Title: Evaluation of Laser Based Alignment Algorithms Under Additive Random and Diffraction Noise

Conference ·
DOI:https://doi.org/10.1117/12.563804· OSTI ID:15014699

The purpose of the automatic alignment algorithm at the National Ignition Facility (NIF) is to determine the position of a laser beam based on the position of beam features from video images. The position information obtained is used to command motors and attenuators to adjust the beam lines to the desired position, which facilitates the alignment of all 192 beams. One of the goals of the algorithm development effort is to ascertain the performance, reliability, and uncertainty of the position measurement. This paper describes a method of evaluating the performance of algorithms using Monte Carlo simulation. In particular we show the application of this technique to the LM1{_}LM3 algorithm, which determines the position of a series of two beam light sources. The performance of the algorithm was evaluated for an ensemble of over 900 simulated images with varying image intensities and noise counts, as well as varying diffraction noise amplitude and frequency. The performance of the algorithm on the image data set had a tolerance well beneath the 0.5-pixel system requirement.

Research Organization:
Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
Sponsoring Organization:
USDOE
DOE Contract Number:
W-7405-ENG-48
OSTI ID:
15014699
Report Number(s):
UCRL-CONF-207003; TRN: US200807%%739
Resource Relation:
Journal Volume: 5556; Conference: Presented at: SPIE, Annual Meeting 2004, Denver, CO, United States, Aug 02 - Aug 05, 2004
Country of Publication:
United States
Language:
English