- COMPLEX CONVERSIONS
- HELPER ROUTINES
- SEE ALSO
Astro::FITS::HdrTrans::ClassicCam - Magellan ClassicCam translations
use Astro::FITS::HdrTrans::ClassicCam; %gen = Astro::FITS::HdrTrans::ClassicCam->translate_from_FITS( %hdr );
This class provides a generic set of translations that are specific to Magellan ClassicCam observations.
The name of the instrument required to match (case insensitively) against the
CHIPkeyword to allow this class to translate the specified headers. Called by the default
$inst = $class->this_instrument();
Returns true if the supplied headers can be handled by this class.
$cando = $class->can_translate( \%hdrs );
For this class, in the absence of an
INSTRUMEkeyword, the method will return true if the
CHIPheader exists and matches 'C-CAM'. It is not clear how robust this is, or over what range of epochs this keyword was written.
These methods are more complicated than a simple mapping. We have to provide both from- and to-FITS conversions. All these routines are methods and the to_ routines all take a reference to a hash and return the translated value (a many-to-one mapping). The from_ methods take a reference to a generic hash and return a translated hash (sometimes these are many-to-many).
Sets a default airmass at the start of the observation if the
AIRMASSkeyword is not defined.
Converts the base declination from sexagesimal d:m:s to decimal degrees using the
DECkeyword, defaulting to 0.0.
Sets the declination scale in arcseconds per pixel. It has a fixed absolute value of 0.115 arcsec/pixel, but its sign depends on the declination. The scale increases with pixel index, i.e. has north to the top, for declinations south of -29 degrees. It is flipped north of -29 degrees. The default scale assumes north is up.
Returns the data-reduction recipe name. The selection depends on the value of the
OBJECTkeyword. The default is "QUICK_LOOK". A dark returns "REDUCE_DARK", a sky flat "SKY_FLAT_MASKED", a dome flat "SKY_FLAT", and an object's recipe is "JITTER_SELF_FLAT".
Stores the number of offsets using the UKIRT convention, i.e. adding one to the number of dither positions, and a default dither pattern of 5.
Stores the number of reads of the detector, with a default of 2, from the sum of keywords
Determines the observation type from the
OBJECTkeyword provided it is "DARK" for a dark frame, or "FLAT" for a flat-field frame. All other values of
OBJECTreturn a value of "OBJECT", i.e. of a source.
Converts the base right ascension from sexagesimal h:m:s to decimal degrees using the
RAkeyword, defaulting to 0.0.
Sets the right-ascension scale in arcseconds per pixel. It has a fixed absolute value of 0.115 arcsec/pixel, but its sign depends on the declination. The scale increases with pixel index, i.e. has east to the right, for declinations south of -29 degrees. It is flipped north of -29 degrees. The default scale assumes east is to the right.
Returns the UT date as
Time::Pieceobject. It copes with non-standard format in
Returns the UT time of the end of the observation as a
Returns the UT time of the end of the observation in HH:MM:SS format and stores it in the
Returns an estimated UT time of the start of the observation as a
Time::Pieceobject. The start time is derived from the end time, less the
EXPTIMEexposure time and some allowance for the read time.
Returns the lower bound along the X-axis of the area of the detector as a pixel index.
Specifies the X-axis reference pixel near the frame centre.
Returns the upper bound along the X-axis of the area of the detector as a pixel index.
Returns the lower bound along the Y-axis of the area of the detector as a pixel index.
Specifies the Y-axis reference pixel near the frame centre.
Returns the upper bound along the Y-axis of the area of the detector as a pixel index.
These are ClassicCam-specific helper routines.
Converts a sky angle specified in d:m:s format into decimal degrees. The argument is the sexagesimal-format angle.
Returns the detector speed in seconds. It uses the
SPEEDto derive a time in decimal seconds. The default is 0.743.
Returns the UT date in YYYYMMDD format. It parses the non-standard ddMmmyy
Returns the UT time of the end of observation in decimal hours from the
Converts a sky angle specified in h:m:s format into decimal degrees. It takes no account of latitude. The argument is the sexagesimal format angle.
Returns the detector bounds in pixels of the region of the detector used. The region will be one of the four quadrants or the full detector. We guess for the moment that keword
QUADvalues of 1, 2, 3, 4 correspond to lower-left, lower-right, upper-left, upper-right quadrants respectively, and 5 is the whole 256x256-pixel array.
$Id: ClassicCam.pm 14879 2008-02-13 21:51:31Z timj $
Malcolm J. Currie <email@example.com> Tim Jenness <firstname.lastname@example.org>.
Copyright (C) 2008 Science and Technology Facilities Council. Copyright (C) 1998-2007 Particle Physics and Astronomy Research Council. All Rights Reserved.
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