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Create DSS image
M97 example
Requires
Trouble shooting Error messages
Can't find image with proper CD inserted
No Image found to extract
Unable to access the headers
path
First things first.
Before creating the DSS image
from TheSky first make
sure that CCDSoft/RealSkyView
are able to create DSS images on their own. This will verify that you
have the correct settings in the DSS Setup dialog.
CCDSoft 5
- Research | Sky Survey Digitized | Sky Survey Setup
RealSkyView - DSS | Setup
Check your CD and hard drive settings
and the Headers path
RealSkyView users must TYPE in
the proper drive letter and path. Entering the wrong headers
folder will yield the following error message! See below!
CCDSoft users can Browse the
hard disk for the Headers folder.
Invalid headers folder
specified!
Change the headers path
RealSkyView users simply
install the application using the installation Disk V. This will
install the RealSkyView application and copy the headers folder to the hard
disk for you. RealSky users with both North and South MUST
install using the CD that came with
RealSky South!
NOTE: CCDSoft
users must copy the Headers folder from the RealSky disk "V" installation
disk. The headers folder can be placed on any drive and in any folder.
Check your drive settingsCCDSoft
Use the "..." button to the right of
Headers Path
The headers folder can be
placed anywhere on any drive!
Choose the option "Low
compression (requires the 102 CD-ROM Digitized Sky Survey)" above AND
then copy the headers from the CD-ROM labeled #102 on to your hard disk.
DSS 102 CD set
Copy headers from CD-ROM #102
Make sure you are using the installation found on CD-ROM V that is
included with RealSky South.
This CD with the copyright (see below) has the newer header files that
support the entire sky.
CCDSoft users need to copy the
headers folder from the installation CD on to the hard disk and then change the above
headers path. If you have the wrong headers you
will not be able to access all of the images. The message No Image
found to extract will result. Also make sure you have the latest
update to
RealSkyView and or
CCDSoft as
well.
For those wanting to copy all
of the CD's to the hard disk (102 Palomar set or RealSky 18) please see
knowledge base
article 1044 for complete details.
In
CCDSoft use Research |
Digitized Sky Survey | Target List and open the Messier target list provided
with CCDSoft/RealSkyView.
Open the Messier.LST file
and find M97
Press the View button
You must have a CD-ROM from
RealSky in the drive BEFORE attempting to create the image. CCDSoft
does not know which CD it will need until then (cart before the horse)! This is why
installing all the
CD's to the hard disk is best whenever possible. If you have the
data on the hard disk or the proper CD-ROM in the drive CD#2 for RealSky or
CD #70 for the 102 CD version you will never be prompted and the images are
created almost instantaneously!
NOTE: 200 gig hard drives are
now as low as $98.00!
TheSky6 prompting for CD
M97 found on RealSky CD#2
NOTE: Note the north
angle for the DSS image of M97 is not 0.00 degrees! This is indicated by the
North/East indicator on the image above in the upper left. The north
angle is actually 3.4 degrees.
In
CCDSoft use Research |
Digitized Sky Survey | Orientation. In RealSkyView use DSS |
Orientation to enable the North/East indicator plotted on the DSS image.
Note: The position
angle will change with the DSS images! The following example image of
the Trifid nebula in TheSky demonstrates this. This north angle is
nearly 0 degrees at 0.31 degrees.
When you can successfully create DSS images using
CCDSoft/RealSkyView
you can then find an object in TheSky and have an embedded DSS image created
for you.
After centering the object of interest (Edit | Find M97 in the example) use
Tools | Image Link | Create Digitized Sky Survey Image as shown below.
Tools | Image Link |
Create Digitized Survey Image
CCDSoft/RealSkyView will create image
You can also use the Image Link Tool bar to create DSS images from a single
button. See below. Enable the tool bar using View | Tool Bars |
then Setup.
Image Link
Tool Bar
The following animated GIF
shows what happens when the Create DSS option is used in TheSky.
Example TheSky before creating
DSS
image
Default Owl Nebula Thumbnail image not displayed for clarity!
And after,
note the position angle will change!
RealSky/DSS data
copyright
North Angle shown for M97
by TheSky
Image Link Tool bar Create DSS image
RealSky/DSS data
copyright
Regardless of TheSky's current
position angle (91.54 degrees above) AFTER creating the DSS image TheSky's
position angle will automatically be adjusted to match the image north
angle. To see this enable the handy Rotate tool BEFORE
creating the DSS image in TheSky.
TheSky's View | Reference
Lines
The North and East directions are now
displayed
North/East indicator
visible
North angle nearly 0 degrees
RealSky/DSS data
copyright
Problematic images -
Near the north and south celestial pole
NOTE: The closer you
get to the north celestial pole the worse the distortion. Meaning that
the images in TheSky will not exactly match the DSS image.
6 degrees from the North
Celestial Pole
Note Red markers are stars from TheSky
RealSky/DSS data
copyright
Here you can see the error.
The red stars from TheSky do not match the DSS stars. The smaller the
field of view the smaller the distortion. This is normal.
The above example EXE file was
made using Microsoft Camcorder. Be patient. The image delay is
the time it takes to create an image from the CD-ROMS. Accessing the
data on the hard drive is nearly instantaneous!
M51 DSS image created by TheSky & RealSkyView
One mouse click creates the DSS image
RealSky/DSS data copyright
The north angle found for M51 is
2.26 degrees.
NOTE: If you are not at
2 degrees or less when using TheSky version 6 and CCDSoft 5 TheSky will default to a
1 degree 25 arc minute field BEFORE
creating the DSS image. TheSky5 version will set a default field of 30 arc
minutes if you are outside of 1 degree. TheSky version 5 is limited to only a 1 degree field
as well as CCDSoft 4 and RealSkyView. CCDSoft 4 and RealSkyView users can
upgrade to CCDSoft 5 for only $99.00. Software Bisque Support Corner
for upgrades.
FAQ's (Frequently Asked Questions)
How can I find the planets on the plates?
Most if not all of the brighter planets were intentionally avoided when the
data was created. The data is used by the Hubble telescope for positioning
so the goal was to reach all faint stars for reference. Pluto can easily
be found on the plates using TheSky because it does not move very fast. I
suspect that Uranus and Neptune are also imaged but have not found them myself.
The following web page shows exactly how to identify Pluto on the data using
TheSky
Minor Planets on the other hand CAN be found.
Provided you have orbital elements close to the date the plate was taken.
Using current orbital elements for the minor planets may or not work depending
on stable the minor planet orbit is.
Can I load only the Northern or Southern Hemisphere for my latitude to save
some space?
Yes. Keep in mind the cut off declination for the North is about the
declination of the star Sirius so you won't get any images below that if you
only use the Northern set. Using TheSky you can plot the CD-ROM numbers
that cover the area of sky for you latitude then only copy those CD ROM numbered
discs that are visible using both North and South data to fill in the gap. Remember that you will loose any
other objects not visible from your location if you do so. Because hard
drive space is incredibly cheap now the easiest and best solution is simply to
install 18 CD-ROMS.
CD Rom numbers for both North and South at 39.5 degree
latitude
Note the higher numbered CD's 11-15 from the South set
How can I see what CD-ROM number is needed for
the area of the sky I am looking at?
There are Sky database files
(SDB files) included with TheSky that contain the CD-ROM numbers for plotting over TheSky
display. There is one for the North "RealSky North.SDB", one for the South,
"RealSky South.SDB" and one for both RealSky "North & South.SDB" The plate number and date/time can also be plotted if you like.
This way you can see what areas of sky are covered by what CD-ROM numbers.
The following page has details on how to activate the SDB files.
The SDB files are found in the
\TheSky6\User\SDB's folder.
There are 4 SDB's. The POSS.SDB is the entire
sky using the 102 CD-ROM set, RealSky North, RealSky South and RealSky North &
South. Following is the folder showing these.
Add the ones you want
Double mouse click or press Add
These SDB's are of object type
Reference Point. Make sure that Reference Point is set to visible or they will
not show! Click here for complete details on
the use of SDB files.
RealSky North distribution using RealSky North SDB
Northern data cut-off at ~15 degrees declination
Please contact the
Software Bisque Support Corner
for questions.
If you have only the Northern hemisphere version
of RealSky CD's 1-8 and try to access objects below the -15 degree cut-off (see
above) you will receive the error message No Image found to extract. And
the same is true for having only the Southern version when trying access objects
above -15 degrees south. RealSky North and South users need not be
concerned.
However you MUST use the
headers from the RealSky Disk V
that is included with the south or you will see the above error message when
trying to access the North!
If you have the correct CD placed in the drive
and yet you still are prompted to insert the same CD-ROM the CD-ROM drive letter
in the DSS setup is not correct or you have inserted
the CD-ROM into the wrong CD drive. See error below.
Wrong CD in the drive OR 
wrong CD drive letter specified in the
DSS | Setup
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