Filter induced errors in laser anemometer measurements using counter processors
Abstract
Simulations of laser Doppler anemometer (LDA) systems have focused primarily on noise studies or biasing errors. Another possible source of error is the choice of filter types and filter cutoff frequencies. Before it is applied to the counter portion of the signal processor, a Doppler burst is filtered to remove the pedestal and to reduce noise in the frequency bands outside the region in which the signal occurs. Filtering, however, introduces errors into the measurement of the frequency of the input signal which leads to inaccurate results. Errors caused by signal filtering in an LDA counter-processor data acquisition system are evaluated and filters for a specific application which will reduce these errors are chosen.
- Publication:
-
NASA STI/Recon Technical Report N
- Pub Date:
- May 1985
- Bibcode:
- 1985STIN...8530288O
- Keywords:
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- Doppler Effect;
- Errors;
- Laser Anemometers;
- Optical Filters;
- Data Processing Equipment;
- Error Analysis;
- Measuring Instruments;
- Noise Reduction;
- Instrumentation and Photography