SYNCALIB

Name

syncalib

Purpose

Create a synthetic suite of calibration images: biases, darks and flats.

Description

Creates a set of randomly generated bias, dark and flat images
as FITS files suitable for input to mkcalib. The number of
images of each type may be selected.

Calling Sequence

syncalib, root,nbias,ndark,nflat,seed

Inputs

root - prefix of file names for calibration, typically YYMMDD- a
'.' is automatically postpended to this name.
nbias - number of bias frames to make.
ndark - number of dark frames to make.
nflat - number of flat frames to make.
seed - random generator seed (which is passed transparently).

Optional Input Parameters

Keyword Parameters

OVERSCAN - integer, number of columns for the explicit overscan area.
if <= 0, there is no overscan area generated
and dimensions of the output images match the base images.
DDIR - String, name of directory where files are to be written.
BIASSTARTFRAME - first fits file number for created biases. File names
are of the form root.FFF where FFF is the file number.
If not specified, file numbers start after the maximum
file number of the current population of DDIR.
DARKSTARTFRAME - first fits file number for created darks. File names
are of the form root.FFF where FF is the file number.
If not specified, file numbers start after the maximum
file number of the current population of DDIR.
FLATSTARTFRAME - first fits file number for created flats. File names
are of the form root.FFF where FF is the file number.
If not specified, file numbers start after the maximum
file number of the current population of DDIR.
DARKEXP - Adopted exposure time in seconds for dark frames- the
default is 600 secs.
FITSTAG - Optional tag to add to files names (commonly .fits). The
default is to NOT add such a tag.
FLATMINEXP - minimum exposure in seconds for flats- for each flat, an
exposure time is adopted as a uniform draw between
FLATMINEXP and FLATMAXEXP. The default for
FLATMINEXP is 3 secs.
FLATMAXEXP - maximum exposure in seconds for flats- for each flat, an
exposure time is adopted as a uniform draw between
FLATMINEXP and FLATMAXEXP. The default for
FLATMAXEXP is 25 secs.
FLATSIGMIN - minimum sky level in photons for flats- for each flat, a
signal level is adopted as a uniform draw between
FLATSIGMIN and FLATSIGMAX. The default for
FLATSIGMIN is 8000 photons.
FLATSIGMAX - maximum sky level in photons for flats- for each flat, a
sky level is adopted as a uniform draw between
FLATSIGMIN and FLATSIGMAX. The default for
FLATSIGMAX is 26000 photons.
GAIN - gain used for darks and flats. Default is
2.0 photons or electrons per D/N.
RDNOISE - Read noise for biases, darks and flats. Default is
10 electrons per pixel.
BIASLEVEL - Bias (overscan) level for biases, darks, flats and
overscan (in D/N).
BIASBASE - Name of FITS file holding the idealized bias image. The
default is syn.bias
DARKBASE - Name of FITS file holding the idealized dark image. The
default is syn.dark. If this does not exist AND
ndark is 0 AND DARKEXP is at a default value, a
pattern of all zeros is generated on the fly.
FLATBASE - Name of FITS file holding the idealized flat image. The
default is syn.flat
CLEANDATA - Flag, if set, there will be no external blemishes added to
the calibration files. Otherwise, stars are added to
flats and cosmic rays to all images except overscan areas.
COSMICCOUNT - Mean number of cosmic ray striks added to images.
STARCOUNT - Mean number of stars added to flat images,
VERBOSE - Flag, if set, will enable 1 line summary for each frame.

Outputs

All output is confined to files. Images are int arrays with a minimum
FITS header including EXPTIME for darks and flats.

Common Blocks

Side Effects

Restrictions

All frame numbers must be in the range 000-999.

Procedure

Modification History

2006/07/10, Written by Peter L. Collins, Lowell Observatory
2006/07/13, PLC, add VERBOSE and fix docunent header.
2006/07/14, MWB, added FITSTAG keyword and added to library.