### F Changes

F.1 Release 2.0

F.3 Release 2.1
F.4 Release 2.2

F.10 Release 3.0-1
F.11 Release 3.1-0
F.12 Release 3.1-1
F.13 Release 4.0-10
F.14 Release 4.0-11
F.15 Release 4.0-12
F.16 Release 4.0-14
F.17 Release 4.0-15
F.18 Release 4.0-16
F.19 Release 4.0-17
F.20 Release 4.0-18
F.21 Release 4.0-19
F.22 Release 4.0-20

#### F.1 Release 2.0

CCDPACK has changed a great deal in this release, the more important features are listed here:

• Automated reduction is now supported. This introduces the commands:

The XREDUCE command is a X based GUI for performing reductions. This has been specifically designed to help novice and infrequent reducers of CCD data, but is expected to be of some use for more experienced astronomers too.

• All reduction programs now perform extra checking to make sure that the requested analyses make sense (so you cannot flatfield before debiassing your data).
• The documentation has been updated and improved. In particular more examples have been added, the new applications have been documented and advice for IR data reducers has been added. A hypertext form of this document is also available and can be viewed from the XREDUCE help system, or by using the command ‘ccdwww’.
• The DEBIAS routine now uses the official ARD release (rather than a prototype implementation). This means that the format of ARD files has changed. ARD keywords now require that their arguments are surrounded by parentheses and are separated by commas. See the ARD description in this document for more about the ARD format.

There have also been many low-level changes to the package, any bugs reported during 1994/1995 should be fixed.

#### F.2 Release 2.0-2

CCDPACK has been updated to fix several outstanding problems.

• The USECOMP parameter of FINDOFF was mispelt as USECOM in the documentation.
• The FINDOBJ application failed with an error message about not being able to allocate less than 1 element of memory when all the pixels lay above the detection threshold. This now correctly describes the problem.
• In the description of the import control table format in the routine IMPORT a reference compared the value of the FITS-keyword OBSTYPE to “FLAT” when it should really have been to “FF”.
• The C-shell CCDALIGN command failed when attempting to work out the global transformations between images. This has been fixed.
• An error that occurred in the XREDUCE GUI when reading in import control tables has been fixed.

#### F.3 Release 2.1

CCDPACK is now available under Linux. Four bug fixes and a minor feature change have also been made:

• The logic of the flag that controls how saturated pixels are marked in the XREDUCE GUI was reversed. This is now works as described.
• The control of window stacking in xreduce has been improved. Menus should appear much faster than before.
• A bug in the memory handling in FINDOFF has been fixed. This resulted in the occasional crash or peculiar behaviour.
• A bug in CCDEDIT related to the classification of type 2 linear transforms has been corrected. This was causing a crash when TR(6) was set to zero.
• A new parameter CLEAN has been added to the MAKEFLAT routine. Setting this flag to FALSE disables the phase that attempts to detect spurious pixels. The default for this parameter is TRUE.
• All NAG source code has been eliminated. This was necessary for CCDPACK to appear on Linux based systems. This effects the following routines: MAKEBIAS, MAKECAL, MAKEFLAT, MAKEMOS, DEBIAS, FINDOFF, REGISTER and CCDGENERATE.

The most significant changes have been made to the MAKEMOS routine. Consequently the old routine is still available, for now, and can be executed by using the command:

nagmakemos

#### F.4 Release 2.2

In this release CCDPACK can now access foreign data files. This makes it possible to wildcard lists of IRAF and FITS files, i.e.:

makemos in=*.fit out=mosaic.imh

CCDPACK can now also be used from the IRAF/CL command interpreter.

More minor changes include:

• A new data combination method has been added. This is a sigma clipped median (“clipmed”).
• An error in calculating the variances when median stacking 2 images has been corrected (previous values where an underestimate).
• The restoration output from CCDSETUP is fixed to work correctly when just recording two bias strip bounds.
• The PAIRNDF application has been improved to give better control of reserved pens.
• The FINDOFF application now reports when any input files have less than 2 positions.
• The IMPORT application now works on Linux.
• The IMPORT application has been extended to allow the concatenation of FITS character strings.
• The SCHEDULE application now uses the correct comment delimeter on Linux.
• The REGISTER application FITTYPE parameter now works when set to 3 (shift of origin and magnification).
• HDS files with an object called DATA_ARRAY which are not NDFs are now correctly ignored.

#### F.5 Release 2.2-1

The applications FINDOFF and REGISTER have been modified to open up to 100 input and 100 output files. Previously these programs where limited to 40 files in total.

The propagation of QUALITY in the MAKEBIAS, MAKECAL, MAKEFLAT and MAKEMOS applications has been suppressed. A bug in TRANNDF when propagating QUALITY has been corrected.

#### F.6 Release 2.3-0

A minor update to CCDPACK.

• A new median stacking method “FASTMED” has been introduced. When used on stacks of 50 images this is typically about 60-70% faster than the existing weighted median. This is very fast as it also usually lies within 10% of the time taken to calculate the mean.
• The CCDALIGN application has been changed so that images of different sizes are displayed at different scales.
• The FLATCOR application has been changed to trap divide by zero on Linux and OSF/1.
• The FINDOBJ application has been changed so that the error resulting from not detecting objects on an image may be overriden.
• There was a problem, under Linux, with the DEBIAS application not accepting a saturation value. This is now fixed.

#### F.7 Release 2.3-1

A minor update to CCDPACK.

• The applications MAKEMOS and MAKEFLAT have been modified to generate output variances based on the scatter of the input images.
• A parameter OVERRIDE has been added to FINDOFF. This now stops the program if a partial solution to the registration is found.

#### F.8 Release 2.4-0

This is a minor update to CCDPACK. It corrects several bugs and introduces a small amount of new functionality.

• The applications MAKEMOS and MAKEFLAT have been modified to generate output variances based on the scatter of the input images.
• A parameter OVERRIDE has been added to FINDOFF. This now stops the program if a partial solution to the registration is found.
• The applications FINDCENT, CCDALIGN and PAIRNDF have been improved to work more effectively with large images. Previously the centroiding technique they used failed because typical X window displays are not capable of showing images at sufficient resolution to obtain a good starting position.
• A bug in the image display part of XREDUCE has been fixed. This was caused by an incompatibility introduced in a release of KAPPA.
• The parameter files for the IRAF version of CCDPACK should now be synchronised (several where missing some new parameters). The "use_globals" command now works as described.

#### F.9 Release 3.0-0

This is a major update to CCDPACK.

• CCDPACK has been revised to be aware of, and use, the World Coordinate System (WCS) components of NDFs - see SUN/95 and SUN/210. This has had the following effects on the package:
• Some new applications have been introduced:
• ASTEXP – Exports AST frameset information from NDFs to file
• ASTIMP – Imports AST frameset information from file to NDFs
• WCSEDIT – Adds, removes, makes current frames in WCS component
• WCSREG – Aligns NDFs using multiple WCS component frames
• A new test script is available:
• WCSEXERCISE – test WCS-related functionality (not IRAF)
• Coordinate transformations are now stored using AST coordinate frames in the WCS components of NDFs, rather than using TRANSFORM structures stored in the .MORE.CCDPACK extension. For backward compatibility however all applications retain their old ability to read TRANFORM structures.

The position list coordinates dealt with by FINDOFF and REGISTER are now by default converted from pixel coordinates to the Current coordinate system before use (USEWCS parameter). In addition FINDOFF can optionally restrict attempted object matches to regions expected to overlap (RESTRICT parameter).

• FINDOFF – new parameters maxdisp, restrict, usewcs
• REGISTER – new parameters outdomain, simpfi, simpif, usewcs, wcsfile
• TRANLIST – new parameters framein, epochin, frameout, epochout, wcsfile
• TRANNDF – new parameter usewcs
• MAKEMOS – new parameters correct, writesz

The following script is affected:

• CCDEXERCISE
• All applications now propagate WCS components where appropriate. This affects, in addition to those mentioned above, the following applications:
• The package now requires AST 1.4 to build.
• A new application, DRIZZLE, has been introduced. This resamples and combines images in one step, optionally normalising them at the same time. It uses the variable-pixel linear reconstruction, or “drizzling” algorithm, which is well suited for combination of multiple dithered undersampled images.
• FINDOFF will now deal with position lists having as few as one object in common. This capability will principally be of use in conjunction with the new WCS awareness of the package.
• The package will no longer attempt to make use of NAG routines where present. The following routine is withdrawn:
• NAGMAKEMOSMAKEMOS should be used instead.
• There are other some minor changes in behaviour:
• Some routines fail differently when objects cannot be matched:
• FINDOFF erases the associated position list of NDFs which cannot be matched instead of leaving the previously associated list.
• REGISTER ignores NDFs without associated position lists instead of exiting.
• REGISTER: output to screen has changed slightly for readability.

#### F.10 Release 3.0-1

Release 3.0-1 makes a few non-user-visible code modifications and minor documentation bugfixes to the beta test release 3.0-0b. The WRITESZ parameter of MAKEMOS is also withdrawn and the defaults of the CORRECT parameters in MAKEMOS and DRIZZLE correspondingly modified.

#### F.11 Release 3.1-0

This is a minor update of CCDPACK, and incorporates the following changes:

• As of this release, the handling of group parameters is done using the GRP and NDG libraries as in some other Starlink packages, notably KAPPA. For most purposes behaviour will be unchanged, but now when specifying a list of images, the name of an HDS container file holding several NDFs may be given, and each of the contained NDFs will be processed as a separate image. This affects almost all the CCDPACK tasks.
• DRIZZLE has been substantially speeded up and some bugs removed.
• The percentile location algorithm in FINDOBJ has been improved to deal better with images containing a few rogue pixels with far outlying values.
• The IMPORT task has been improved so that it can use hierarchical FITS header keywords, and values in FITS headers of the form ’[X1:X2,Y1:Y2]’.
• The behaviour of IDICURS and PAIRNDF and on TrueColor visuals (typically newer Linux X displays) has been improved; they now signal an error rather than just crashing. In a future release these applications will be replaced by ones which run properly on these visuals.
• An improved version of the AST file INT-WFC.ast, for astrometry of frames from the WFC mosaic camera on the Isaac Newton Telescope, has been included in the distribution.

#### F.12 Release 3.1-1

This is a bugfix update of CCDPACK, and incorporates the following change:

• There has been a bugfix which affects median stacking in MAKEBIAS MAKECAL, MAKEFLAT and MAKEMOS. Previously when METHOD=MEDIAN and variances were not being used, some pixels received the wrong weighting. This has now been fixed.

#### F.13 Release 4.0-10

This is a major update of CCDPACK; major new facilities have been added in these areas:

CCDPACK Sets (mosaic cameras):

CCDPACK now offers the concept of a Set of image files, which will typically be a group of frames taken from the different CCDs on the same mosaic camera during the same observation. This makes the data reduction and registration much more straightforward when processing this type of data. Two new applications have been added for explicit handling of Set header information:
• MAKESET – Writes Set header information to images
• SHOWSET – Outputs image Set header information

The existing CCDPACK applications have been modified to be aware of this Set information, but will behave as previously on data which has not had Set headers explicitly added. A new test script has been added to show off the new capabilities:

• SETEXERCISE – Tests CCDPACK Set functionality
Interactive registration programs:

The following programs have been completely rewritten:
• IDICURS – Views and writes position lists interactively
• PAIRNDF – Aligns images graphically by drag and drop
• CCDALIGN – Aligns images graphically by interactive object selection

They now feature a much more intuitive, powerful and easy to use graphical interface than in their previous incarnations. They will also work on all X displays, rather than requiring a PseudoColor visual as previously. Although these programs offer basically the same facilities as they did in previous versions of CCDPACK, parameter usage has in some cases changed considerably.

New display application:

The following new program has been added for viewing images and their alignment:
• DRAWNDF – Draws aligned images or outlines on a graphics display

It will plot the outline, or the pixels, or both of one or more images on a display device. This makes it quick and easy to preview the positioning of images in their Current coordinate system, and to see how they are aligned with each other, for instance prior to resampling and generating a mosaic.

Other items:

The following minor changes have also been made since v3.1-1.
• Some bugs in FINDOFF, including one which caused failure when NDFNAMES=false, have been fixed.
• FINDOFF will now propagate values in trailing columns from the input to output position lists.
• PLOTLIST has been modified to interact with the AGI database in a more KAPPA-compatible way, so that alignment with KAPPA graphical output should be improved.
• There have been some improvements and bug fixes to the percentile location routine used by FINDOBJ.
• The MODIFIED parameter of WCSEDIT has been withdrawn and replaced by the NAMELIST parameter.
• TRANNDF will now (sensibly) refuse to resample into a SkyFrame.
• There is improved crossreferencing in SUN/139 from “See also” sections in the task descriptions Appendix back to the main text.
• Programs which deal with attached position lists will now normally use a position list file with no entries rather than not using an attached position list at all.

#### F.14 Release 4.0-11

FINDOFF bug:

A bug which caused problems with OVERRIDE=TRUE in FINDOFF has been fixed. This is only likely to have caused problems to ORAC-DR users.

#### F.15 Release 4.0-12

REGISTER FITTYPE=6 bug:

A long-standing bug which prevented REGISTER from working with FITTYPE=6 has been fixed.

#### F.16 Release 4.0-14

TRANNDF modification:

In TRANNDF a copy of the pre-transformation PIXEL coordinate system will be preserved, under the name CCD_OLDPIXEL, in the World Coordinate System component of the transformed image.
Bugfixes

• A bug in which TRANNDF with linear interpolation failed to apply flux conservation has been fixed.
• An improvement to the histogram determination routine used by FINDOBJ and DRAWNDF has been made.

#### F.17 Release 4.0-15

Bugfixes

• When REGISTER is used with NDFNAMES=FALSE and PLACEIN=SINGLE, a new NDF will be created using the WCSFILE parameter if one does not already exist.
• In TRANNDF a bug in which flux conservation was lost when using flipped images has been fixed.

#### F.18 Release 4.0-16

Bugfixes

• A MAKEMOS bug has been fixed.

#### F.19 Release 4.0-17

Limit changes

• Some of the file number restrictions have been loosened. You can now execute most tasks with up to 1000 files (up from 100) and you can perform FINDOFF matching with up to 400 (up from 100).

#### F.20 Release 4.0-18

Limit changes

• Modified for use in 64-bit environments (CNF_PVALs added).

#### F.21 Release 4.0-19

DRIZZLE

• A new parameter GENVAR has been added, so that the variance array does not need to be written in the output.
• Extensions are now propagated from the first input NDF to the output one.

#### F.22 Release 4.0-20

The Tcl/Tk/Itcl core that CCDPACK uses has been updated. Extensive minor changes to the XREDUCE application.