---

In short, yes. There are some simple steps required to do so and a few important caveats associated with upgrading the imager, all of which are described in this FAQ.

When a CIAO release is being prepared, the most recent version of ds9 available is used in testing and then packaged with the software. Since updates to ds9 are released on a much shorter timescale than CIAO, users may wish to upgrade independently of CIAO to take advantage of new features and bug fixes. The ds9 version 3.0 release notes list all the changes made between versions.

To use a different version of ds9:

1. Start CIAO

2. Change the ASCDS_IMAGER_PATH variable to point to the location of the newer imager on your system:

   unix% setenv ASCDS_IMAGER_PATH /your/ds9/path
   
   unix% ls $ASCDS_IMAGER_PATH/ds9
   /your/ds9/path/ds9
   

3. Edit the PATH variable so that the new imager directory appears before the CIAO OTS directory:

   unix% setenv PATH "/your/ds9/path:$PATH"
   
   unix% $PATH
   /your/ds9/path:/soft/ciao/ots/saord:/soft/ciao/bin:/soft/ciao/contrib/bin:/opt/SUNWspro/bin:/usr/ccs/bin:/usr/ucb:...
   

   This step is optional, but recommended.

Following these steps will make the new imager available to CIAO, including imaging plots created by Sherpa.

Caveats

• We do not guarantee that CIAO will work flawlessly with a newer release of ds9! The software team only tests the version of ds9 included with CIAO; it is possible that subsequent changes to the imager may cause unexpected problems in the CIAO software. Users who experience problems may contact the CXC HelpDesk, and we will do our best to assist you.

• The preferences set in ds9 are stored in a file called $HOME/.ds9.prf. A preferences file created for an older or newer version of ds9 may cause problems with the ds9 packaged in CIAO. To avoid a possible conflict, delete or rename this file. The Preferences section of the ds9 manual contains more information on avoiding this problem when supporting multiple versions of ds9.

For more general information on how to use ds9, refer to the Using SAOImage ds9 thread.

---