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SimCCD V2.1.0


Appendix A – Release Notes


This appendix describes recent changes to SimCCD and Exposure Planner

SimCCD Version 2.1.0

SimCCD can now read the FITS files that CCDStack creates.  For this to work, you must use a patched version of the fitsio library (in fits.jar) that is provided in the distribution kit.


SimCCD optionally crops the user’s source image before processing it.  This makes the program more responsive and less likely to run out of memory.  The user can choose the size of the cropped region.  By default this option is turned on.


SimCCD optionally displays a reduced resolution image of the simulation result.  This makes the program more responsive and less likely to run out of memory.  By default this option is turned on.


SimCCD will crop the source image if it is too large to fit into the available memory.  This feature is not optional, since it is needed to keep SimCCD from crashing.


SimCCD uses memory more efficiently, so it is much less likely to run out of memory.


Added Vixen VMC260L and Astro-Physics Gran Turismo telescopes to the equipment list.


When a source file is being opened, the simulation name field is now wide enough to see the whole name.


Today’s date is printed in the message window at startup time.


Some typos have been corrected in the manual.

Exposure Planner V1.2

Because of the way color cameras work, Exposure Planner cannot be expected to work with a color images, but at least it gives a more helpful error message when it encounters one.


The email button now works.


There is now a help button.


The version number is displayed.

SimCCD Version 2.0.4

SimCCD now calculates the sky brightness correctly.  In previous versions, when SimCCD displayed the brightness in units of magnitude per square arc second, the value depended too much on the filter choice.  Now the value is roughly independent of the filter.  Moreover it is in closer agreement with Unihedron’s Sky Quality Meter.


Fixed run_simCCD.command so that it works correctly on a Macintosh.


Fixed run_simCCD.command and to work correctly with folder names that contain multiple adjacent blanks.


Fixed Run_SimCCD.vbs so that it is aggressive about finding where Java is installed.  This should help solve problems people have reported getting SimCCD to work on 64-bit versions of Windows 7.


Clarified the manual to remind users to unpack the distribution zip file.


Added RCOS 1.4.5” and Astro-Physics 155 EDF telescopes.


This release includes new Exposure Planner V1.2.

Version 2.0.3

Includes Exposure Planner V1.1, which fixes a serious bug that made the plug-in almost unusable.  Previous users may need to reboot their system before the installer can replace the old version.


Added definition for Atik 383L+ camera


Fixed bug that made windows too small when two monitors were being used.

Version 2.0.2

Fixed SimCCD so it runs correctly with Java 1.7.

Version 2.0.1

Fixed the code for checking licenses.

Version 2.0.0

SimCCD has a new statistics window, which shows information about a selected region in the image.  The region can be selected by dragging the mouse over the image.  The window also gives a recommendation for how many exposures will be needed to reduce the noise to an acceptable level.


There is a new Exposure Planner plug-in for MaxIm DL.  This plug-in is much easier to use than SimCCD and gives the user a recommendation for how many exposures to take to reduce the noise to an acceptable level.


SimCCD now lets you use your own files for source data.  Users in the Southern hemisphere will no longer need to rely on SDSS data files.  This feature is especially useful for planning exposures.


The DOS console window no longer appears.  You start SimCCD using a new file Run SimCCD.vbs, which replaces Run SimCCD.bat.  If the script has trouble starting SimCCD, it will bring up a console window and that can help you figure out what went wrong.


The 2X Barlow was specified incorrectly.


Bug fixed: A zero value for the readout noise could make the control panel unusable.


SimCCD now lets you choose the sky value when the source file is opened, and then later on the fly if the wrong value was entered.


You can get help in picking the exposure time by looking at the log messages that report EXPTIME and SNAPSHOT.


You can now blink images.  You can either blink between the source and simulation data, or blink between two (or more) simulations.


Memorize window positions.


All windows must appear on screen and not be too large.


SimCCD now requires a license to operate in full-featured mode.  The license is free.


Problem: run_simccd.command doesn't work on MacOS.  This hasn’t been fixed; but if you rename the installation folder so it doesn’t have blanks and parentheses, the problem should go away.  The new distribution kit uses an acceptable name.


We have added a close command, which leaves SimCCD running.


Console messages can't be seen.  Fixed by redirecting them to the log message window.


SimCCD uses too much memory.  Several fixes have reduced the memory footprint considerably.  Most users will no longer need to adjust Java’s Xmx and Xmn parameters.


The “about box” now gives more information, and provides a direct link to the SDSS site, which should make it much easier to find source data.


There is a new “check for updates” menu item


Definitions have been added for ten new cameras.


A button bar was added to make it easier to zoom.


Zooming now keeps the image centered.


You can now clear the log or add a message to it by right clicking in the log window.


Version 1.0.1

Read compressed FITS files (files with names like xxx.fits.gz).


Read FITS files from many sources, including files that contain color data.  If a file contains more than one image, the user is asked which one to use.


When a simulation is deleted, make sure the control panel is switched so that it controls the new top-most simulation frame.  (Before this change was made, the control panel tried to update the simulation that had been deleted, so nothing changed.  That made it seem like SimCCD wasn’t respecting your changes.)


Use latest version 1.04.0 of the fitsio library.  Also rename the library from to fits.jar to conform to the customary convention.  Note that this means all batch startup files had to be changed to use the new name.


The manual gives more detailed descriptions on how to obtain FITS files from sites besides the SDSS site.  In particular, it gives more information on how to obtain images from the Hubble Space Telescope.


Version 1.0.1b3

The three control panels have been merged into a single window.


A menu bar has been added to every window.


The method for entering the sky brightness has changed.  In previous versions the value was entered as ADU/pixel/second, while the new version uses ADU/pixel.  This is a convenience to the user, who no longer has to divide the measured value by the exposure time.


The BASH shell script script has been improved.  It is now a proper UNIX file, so it will no longer complain about a bad interpreter.  The script has also been modified to ensure that the working directory is correct, which will prevent a “class not found” exception.  Finally the script allocates enough memory to ensure that SimCCD can start properly on most systems.


A command file run_simccd.command has been added that will let users start SimCCD on the Macintosh. It has the same fixes as


Some camera names have been changed to conform to convention.


Added definitions for Starlight Xpress SXVR-H9 camera, PlaneWave 12.5” telescope, and Celestron 11” EdgeHD telescope to SimCCD equipment.xml.


Added a button on the contrast tab that lets you choose between showing the sky as black, which makes it easier to see the target, and showing it at its correct intensity, which gives a more accurate rendition of how bright the sky is compared to the target.


Bug fixed to make it less likely that SimCCD will run out of memory with extremely large images.


Bug fixed to make sure the simulation window doesn’t go off screen for extremely large images.


Bug fixed where new equipment definitions didn’t show up until SimCCD was restarted.


This version of SimCCD should be regarded as a tentative release candidate for V1.0.1, which will be the first official release of SimCCD.

Version 1.0.1b2


A BASH shell script has been added, which should let you run SimCCD on a Macintosh or Unix system.


The memory settings in Run SimCCD.bat have been changed to make it more likely that SimCCD will run on small memory systems.  For people with larger memory systems, a new file Run SimCCD.bat 1.5GB has been added, which uses the old memory paramters in the original batch file.


The contrast controls now work more intuitively and are more sensitive to finer adjustments.  In addition, the automatic contrast control algorithm now shows both the source and simulation images using similar settings, which makes it easier to compare them.


The contrast control sliders now move in bigger increments when you use the arrow keys.


Added definitions for three cameras based on the Kodak KAF-8300 chip: the QSI 583, the Apogee Alta U8300, and the SBIG 8300M.


Added definition for the Takahashi Mewlon 250.  It has been suggested that I also add a definition for the Takahashi FSQ-106 “New Q”, but this scope was actually already part of the initial release.


Added a new equipment definition file named SimCCD equipment.xml.  This file should be kept wherever SimCCD.jar is located.  The file will be updated whenever new equipment definitions are available.


Added new Import and Export commands.  They can be used to transfer equipment definitions from one computer to another.  You can also submit these definitions to our web site to have them included in the next release of SimCCD.