| Zugriffsnummer | 22041 |
| Dokumenttyp | Zeitschriftenartikel |
| Sprache | Englisch |
| Titel | Measurement uncertainty and temporal resolution of Doppler global velocimetry using laser frequency modulation |
| Autor(in); Institution |
Fischer, Andreas; Dresden University of Technology, Chair of Laser Metrology, Dresden, GERMANY
Büttner, Lars; Dresden University of Technology, Chair of Laser Metrology, Dresden, GERMANY
Czarske, Jürgen; Dresden University of Technology, Chair of Laser Metrology, Dresden, GERMANY
Eggert, Michael; 1.4, Gase, PTB-Braunschweig
Müller, Harald; 1.4, Gase, PTB-Braunschweig
|
| Quelle/Jahr | Applied Optics: 47 (2008), 21, 3941 - 3953 |
| ISSN | 0003-6935 |
| DOI | |
| URL | |
| Verlag | Washington, DC: OSA |
| Klassifikationscode | OCIS: 120.0120 ; OCIS: 120.7250 ; OCIS: 280.7060 ; OCIS: 280.2490 |
| Freie Schlagworte | Doppler global velocimetry (DGV) ; frequency modulation ; avalanche photo diode array ; time resolution ; measurement uncertainty |
| Zusammenfassung | A Doppler global velocimetry (DGV) measurement technique with a sinusoidal laser frequency modulation is presented for measuring velocity fields in fluid flows. A cesium absorption cell is used for the conversion of the Doppler shift frequency into a change in light intensity, which can be measured by a fiber coupled avalanche photo diode array. Because of a harmonic analysis of the detector element signals, no errors due to detector offset drifts occur and no reference detector array is necessary for measuring the scattered light power. Hence, large errors such as image misalignment errors and beam split errors are eliminated. Furthermore, the measurement system is also capable of achieving high measurement rates up to the modulation frequency (100 kHz) and thus opens new perspectives to multiple point investigations of instationary flows, e.g., for turbulence analysis. A fundamental measurement uncertainty analysis based on the theory of Cramér and Rao is given and validated by experimental results. The current relation between time resolution and measurement uncertainty, as well as further optimization strategies, are discussed. |
