There are 2 components to the Standard Calibrations (see next section for more details):

• Instrumental Calibration
• 10 biases
• 3 dome flats in each of the standard filters
• 3 twilight flats in each of the standard filters
• Photometric Calibration
• 3-4 Landolt standard star fields taken throughout the night

If the Service program uses the standard filters, the standard instrumental calibration will be performed automatically (i.e. there is no need to request it in the README file). If the Service program requires PHO or CLR conditions, it is possible to request standard photometric calibration. If you wish to have photometric standards observed for your program, please indicate this clearly in your README file. Note: it does not make sense to request standard photometric calibrations if your program requests THN conditions.

If the program contains filters other than these, you MUST create your own calibration OBs for skyflats (max. 3 per filter), domeflats and standard stars (biases will be taken for you regardless). If these specific calibration OBs are not included, no calibration in these filters will be undertaken by the 2p2team. Users requiring such calibrations are charged the time taken to execute them, with an upper limit being 10% of the awarded time. These calibrations are not a part of our Standard Calibration Plan but are executed where necessary. Repeat calibrations (on different days) must be specified individually, unless prior arrangements have been made with USG and the 2p2team.

More Specifics:


The following table shows the components of the Standard Calibration in more detail:

Component	Exposure Time/Level	Scope	Notes
Landolt Fields	60 s and 120 s per field for U 10 s and 30 s per field for BVRI	Two exposures per field; 3 - 4 fields per night	The Landolt Fields are chosen from the following list: SA92, SA95, SA98, SA101, SA104, SA107, SA110, SA113; Neither dithering nor guide stars are used; Minimum airmass is 1.2, maximum is approximately 1.8; Only a few stars occupy each CCD in the mosaic
Sky Flats	approximately 20000 ADU	At least three per filter used the previous night, (provided the conditions permit)	In extreme cases it may not be possible to obtain this many sky flats for each filter in a single night. The demands of non-standard calibrations will have a bearing on this and will similarly vary from night to night
Dome Flats	approximately 20000 ADU	Three for each filter used the previous night	Taken with the flatfield lamp	--
Bias Frames	0 s each frame	Ten each day following a Service Mode night	Taken irrespective of whether Standard Calibrations were done the night before

A tar file containing the Standard Calibration Plan OBs can be downloaded for perusal. Untar the file and use the Import function of P2PP to load the OBs for viewing.

Any further questions please email the 2p2team. This account is checked daily.

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Send comments to <2p2team@eso.org> Last update: Nov 22, 2001