OCELOT is an Andor iXon+888 EMCDD camera mainly mounted on the RCC telescope. For the operating instructions, see the article Usage of OCELOT on the RCC. It can also be mounted on the 50 cm Cassegrain telescope. Furthermore, it is vital to consult the article Ocelot.
To use the EMCCD we first need to stop the spectrograph:
acectrl --stop. This ensures that the mirror within the telescope tube directs the light in the EMCCD instead of the spectrograph.
On the 1 m RCC telescope:
On the 50 cm Cassegrain telescope:
|Readout||Preamp gain||EM gain||Effective gain (ADU/electrons)|
|16bit/1Mhz||5.1||10||6.58 +/- 0.06|
|16bit/1Mhz||5.1||20||13.40 +/- 0.10|
|16bit/1Mhz||5.1||40||27.67 +/- 0.39|
Note: the usual definition for gains is in the units of electrons/ADU (e.g. as it is used in the widely accepted GAIN keyword in FITS files), hence it is the reciprocal of the above values. For instance, the argument
--gain of the
fiphot tasks of FITSH also expects gain values in electrons/ADU units. However, in the case of a detector electronmultiplying output, the units of ADU/electrons are more closery related to the EMCCD hardware characteristics (see above, the gain in ADU/electrons is quite proportional to the set value of EMgain).