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| P2F | CCD Photometer | EPSIM | |
| A T C | PODEX | SigSpec |
CCD Photometer
Introduction
For international observing campaigns related to the determination of eigenmode spectra of pulsating stars we want to develop a transportable, computer controlled, high precision photometer. The accuracy of individual measurements should be limited by photon noise only.
A survey of the commercial market for appropriate components led us to focus our investigations on CCD cameras. This decision is based on the very high efficiency of modern CCD chips which can be increased up to 90% with special techniques, like back illumination and antireflection coating, and by the possibility to obtain simultaneous photometry of several objects.
A detailed analysis of our needs resulted in the following system requirements:
General Requirements
- CCD-array of about 1000x1000 pixel
- pixel size of about 20x20 micrometer
- quantum efficiency larger than 70% in the visible region
- large full well capacity to ensure a high dynamic range
- 16 bit AD-converter
- dark current less than 0.5 e/pixel/sec (peltier-cooling, liquid nitrogen
is not appropriate for remote sites
- exposure time 10s to 30s
- read out time 10% (maximum 20%) of the exposure time, therefore:
- read out frequency ~1 MHz (minimum 500 kHz)
- read out noise less than 12 e/pixel
- interface to a notebook: PCI, PCMCIA (PC-Card), SCSI, ISA
- software should support FITS-format
We acquired offers from the following companies:
- AstroCam
- Gold Elettronica
- Photometrics
- PixelVision
- Spectra Source
In charge of this page is: Konstanze Zwintz