The velocity sensitivity of resonant scattering spectrometers employing a piezoelastic modulator
Abstract
The resonant scattering spectrometers of the IRIS ground-based network for measuring whole-disc solar velocity oscillations make use of a piezoelastic modulator. The velocity noise generated by this optical component is analysed with particular emphasis on the required stability of the amplitude of oscillation, a. The product of the absolute stability ¦ a − am¦/amand the relative stability δar.m.s./am may not be larger than 10 −4 to 10 −5 (depending on specific wishes), where amis the optimum amplitude. The velocity noise due to photon statistics is slightly enhanced, but other instrumental sources of velocity noise remain unaffected.
- Publication:
-
Solar Physics
- Pub Date:
- May 1991
- DOI:
- 10.1007/BF00149821
- Bibcode:
- 1991SoPh..133...43H
- Keywords:
-
- Piezoelectric Transducers;
- Resonance Scattering;
- Solar Oscillations;
- Spectrometers;
- Velocity Measurement;
- Background Noise;
- Doppler Effect;
- Solar Instruments;
- Sound Waves;
- Standing Waves;
- Instrumentation and Photography;
- Relative Stability;
- Optical Component;
- Absolute Stability;
- Photon Statistic;
- Velocity Oscillation