Accurate frequency measurements of noise-added Doppler signals by means of transient recorders and LDA counters using a laser diode simulator
Abstract
An experimental program is conducted to obtain detailed data on the SNR values desirable in laser Doppler anemometer (LDA) signals, as well as the sample points/cycle required in performing precise frequency measurements with transient recorders. It is noted that a systematic error can be introduced by incorrect hardware design. Comparisons between a commercially available LDA counter and a transient recorder demonstrate that a counter cannot be applied for uncertainties smaller than 0.1 percent.
- Publication:
-
2nd International Symposium on Applications of Laser Anemometry to Fluid Mechanics
- Pub Date:
- 1985
- Bibcode:
- 1985alaf.sympQ...4D
- Keywords:
-
- Frequency Measurement;
- Gas Flow;
- Laser Doppler Velocimeters;
- Nozzle Flow;
- Signal Processing;
- Signal To Noise Ratios;
- Diodes;
- Instrument Errors;
- Fluid Mechanics and Heat Transfer