RealSky
Hard disk Access
System Requirements
- Windows NT/2000/XP
- Windows 98/ME
- Memory 64 megabytes or more
- CD Rom drive
- Hard drive space 2 megabytes to 12 or
more
Software Requirements
The above links will take you directly to the downloads page so you can get
the most recent versions!
Background RealSky Information
The RealSky data was created using 512 byte sectors on the 18 CD-ROMs. This format was chosen to save space because there are literally a million files
spread over the 18 CD's, actually 1.3 million files to be exact. When RealSkyView
was written by Software
Bisque many years ago (~6+) to access this data large hard drives were
either non existent or cost prohibitive for most at best This of course
has now changed for the better.
Note
that the RealSky data must exist on a single drive letter (multiple drives
and/or folders cannot currently be used with the data) AND the data must exist only in the root folder
of the hard drive (subfolders cannot be used unless you are running Windows
NT/2000/XP as described below in the Windows NT/2000/XP section). For
additional background information regarding
RealSky please refer to the "realsky cd
guide" distributed with the data.
To install the RealSkyView
application that comes with the data please refer to the
"realskycd guide" that is included with the CD-Roms for setup instructions and background
information on the data. RealSkyView
users can also upgrade to CCDSoft
version 5 for a an upgrade price of $99.00 by contacting Software Bisque
directly. CCDSoft
5 is a full featured image processing and camera/filter wheel control
package with extensive scripting capability. See the web for details on CCDSoft
5.
Note: If you already have CCDSoft
installed on your system you DO NOT need to install the RealSkyView application
included with the RealSky CD's. RealSkyView is a
subset of the older version 4 CCDSoft.
The CCDSoft
manual has complete details on setting up the program to create the DSS
images. At the point where CCDSoft
can create a DSS image on its' own TheSky will then be able to create the images for
anywhere in the sky you are viewing.
CCDSoft 4 users are encouraged to upgrade to CCDSoft
5. However the CCDSoft 4 manual does have complete details on how to setup the DSS to
access the data. CCDSoft 4 can only create 1 degree square image where as CCDSoft
5 can create 2 full degrees!
Hard disk options
Because a large hard disk is now priced at about $80.00 for ~60 gigabytes
(about $1.25/gigabyte) of storage or 200 for $100.00!, so drive space is very inexpensive and very easy
to come by. A 30 to 60 gigabyte drive is more than enough to handle the 18 RealSky
CD's that occupy 10.1 gigabytes of data on the CD Roms. The
size of the hard disk to purchase for the RealSky data depends on the operating
system being used. The reasons for installing the RealSky
data onto a hard
drive are simple. First you do not have to keep track of which of the 18
CD-ROMS you need to insert for where you are in the sky, and secondly the speed
of a hard drive is much faster than even the fastest 52X CD-ROMS so access time
is minimized. The faster the hard drive the better but something like a 7200
RPM drive works very well and fields as large as 1 degree can be created in only
a few seconds. Newer and faster ATA serial drives (provided
you have the support on the mother board for them) will perform even better but
the cost difference for the performance in this case is hard to justify.
Window 98/ME
There are two limitations when using Windows 98/ME with RealSky because of
the way the data is formatted on the CD's. It is strongly recommended that
you upgrade to Windows 2000 or even better yet Windows XP to easily overcome
them. These newer
operating systems will get around these limitations and they actually perform
much better than previous versions of Windows. However, if you have older
hardware that simply cannot run Windows 2000 or XP the following has details on
what you must do for Windows 98/ME. Windows ME users are strongly
encouraged to switch to Windows 98 if at all possible!
The first issue is the size of the sectors used by the operating system when
formatting the hard drive Because you have no control over this when using
Windows 98/ME the data from the RealSky CD's will occupy much more space than
you would expect. The 18 CD ROMs require a mere 10.1 gigabytes of hard
disk space (that is 650 megabytes/CD times 18 CD's equals 11.7 gigabytes but the
discs are not all full). However, due to the large number of files each
file will require the minimum sector size the hard disk has been formatted
for. Let's look at a simple example. If the smallest sector size on
the hard disk is 1024 then the data will not occupy the expected 10.1 gigabytes
but rather 2 times that or 20.2 gigabytes. Ouch!
If you had purchased a 20 gigabyte hard disk and are running 98/ME thinking that this was plenty of room
for the RealSky data you would find to your dismay
that the Windows 98/ME formatting because of sector size will not hold all of the
RealSky
data. My first experience was using a 30 gigabyte hard disk using
Windows 98 thinking that I had more than enough room. Of course I was
shocked to see the data occupying more than twice what I thought it should.
The second issue with Windows 98/ME is the fact that the data must all be in
the root folder of the hard drive being used. This is not the case with Windows
NT/2000/XP because you can "MAP" a folder to a single drive letter
getting around the issue. Again upgrading to XP or Windows 2000 is highly
recommended to get around this. Mapping a drive letter to a folder simply cannot be done with Windows 98/ME which means that you must copy all of the files into the root folder of the hard
disk being used to hold the data. This is a bit messy because there are so many
folders with so many files that anytime that you are accessing this
drive it will take considerable amount of time to create the folders list. This is very
annoying especially when Windows has to refresh the drive information when using something
like "My Computer" to access your drives. Again, the solution is to use Windows 2000
or XP whereby you can put all the data in a sub folder and then map the folder to a single drive
letter. This is very simple to do and explained in the Windows NT/2000/XP
section below.
For Windows 98/ME users a 40 gigabyte hard disk or larger is the minimum
recommended. Better yet something like a 60 to 80 gigabyte drive is even
better. External USB 2.0 or Firewire drives are also a very good solution
although they are a bit more expensive than buying an internal drive and they
are less convenient. For laptops users that do not have enough hard disk
space available this is usually the
only real solution.
Windows NT/2000/XP
Fortunately Windows NT/2000/XP do not impose the same limitations when
using the RealSky data that Windows 98/ME does. An administrator or
user with administrative privileges can format the hard drive(s) anyway they
like including partitions, size of partitions, and even the file system along
with the sector size to use. Secondly they will also allow you to "map"
a SUB FOLDER on the hard disk to a single drive letter. First you must
share the folder then simply Map the shared folder of data to a single drive
letter. This way you can place
all of the RealSky files in a sub folder rather than placing them all inconveniently
into the root folder of the drive.
The following shows a folder created using Windows XP named
RealSky that has
all of the 18 CD-ROMS of data copied to it. From this you can see that
10.1 gigabytes of free space is not enough to hold all of it. You would
need at least 12.5 gigabytes.
Size of Data using Windows XP
Note number of files and folders
Creating a Partition NT/2000/XP
Warning: If the hard disk to be used to hold the
RealSky data already has data
existing on it (i.e. it is currently already in use) you cannot create a
new partition without loosing everything by formatting it and starting over!
In this case
it is best to add another second new drive for the data if possible or just make
sure you have at least 12.5 gigabytes of hard space free on drive you are
wanting to use. For laptops consider a USB 2.0 or Firewire external hard drive to hold the data if necessary.
Because Windows NT/2000/XP can format the hard drive using the NTFS file
system using 512 byte sectors just like the CD's the 18 CD ROMs of RealSky data will require a
partition size of about 10.1 gigabytes. However I recommend giving
yourself some room even when creating a dedicated partition, more like 13 to 15
gigabytes. Even a smaller, by today's standards, 20
gigabyte hard disk (~$40.00) could be used for the data.
When a hard drive gets "near" full Windows will (annoyingly) continue to warn you
about the hard drive being out of space. So if you have only 12 gigabytes in the
partition there isn't much over head. Again, shoot for 13 to 15 gigabytes
in the partition. Of course the same holds true for the primary hard disk
as well. Keep in mind that filling up a primary hard disk that has the
operating system installed and is booted from on it is a big "no
no".
If the hard drive is brand new and needs to be formatted from scratch you can
create a single smaller dedicated partition for the RealSky data using 512 byte sectors to
optimally hold the RealSky data in the native 10.1 gigabytes of space. Note: You must be an administrator or user with administrative privileges to format
the hard drive and/or create partitions.
Example creating a new 20 gigabyte partition
Use the Administrator Disk Management tools
After the partition has been created you can then format it for
the native 512 byte sectors used by
RealSky. See Below.
Change Allocation unit size to 512
And use the NTFS file system
If adding an additional drive to your system is not an option or your drive
is already formatted make sure you have at least 12.5 gigabytes of free hard drive space to hold the
data. Aovid using the boot hard drive with the operating system installed
if at all possible.
Copying the data to the hard drive
Using Windows Explorer first make a new folder, something like "RealSky Data" on
the hard disk, then patiently copy all of the files and folders on the 18 CD-ROMs of data to the newly
created folder. Select all the folders on each of
the individual CD's and Edit | Copy them and then Edit | Paste them into this
newly created folder. The Copyright file found on all 18 CD's in the root folder
of each CD need not be included! It is the only file in the root folder
and it can be removed from the other selected files. If you copy the file
from each CD you will be prompted with the message to Over Write the Existing
file? That requires you to be there and answer the question.
Sharing the RealSky folder NT/2000/XP
Next "Share" the folder that holds the RealSky data by right mouse
clicking on it and selecting the option "Sharing and Security" from
the menu. Once the folder has
been properly shared it can then be "mapped" to a single drive letter. The
Windows Help will explain how to share a folder as well as map a folder to
a hard drive! See below for details.
At the point where the data is completely copied on to the hard drive and the folder has been
mapped to a single drive letter you can then use the DSS Setup dialog to access the
data. The Setup for RealSkyView is found in the "realskycd guide"
included with the RealSky data. CCDSoft users will find the information
for accessing the DSS data in the
CCDSoft manual.
When you have created a folder that contains all the DSS data it must be
shared first before it can be mapped. Right mouse click the folder using
Windows Explorer then choose the menu option "Sharing and Security" as
shown below.
Share the RealSky data folder
Select Sharing and Security
Select "Share this folder" as shown
Enter comments if you like and press Apply
WARNING!
Because there are so many folders and files
1.2 million files the sharing process
will take a considerable amount of time. Be patient!! Depending on
the drive this could take as long as 10 to 15 minutes to share the million
files! Do not interrupt
the process.
When the RealSky Data folder has been successfully shared there
will be a hand underneath the folder name indicating this as shown below,
Hand Appears on Shared Folder
Now you can Map this folder to a single letter
Mapping a drive letter to a folder NT/2000/XP
To "Map" the RealSky Data folder to a single
drive letter as needed to access the data use Windows
Explorer's menu item Tools | "Map Network Drive..." as shown
below. Highlight the folder to be mapped first!
Choose Windows Explorer's "Tools"
Map the Network Drive
The folder named RealSky Data in this example is now going to be
mapped to a single drive letter "R". You can use any free drive letter
available it make no difference. Here I chose the letter "R" for
RealSky. Click Browse and find the shared folder named "RealSky
Data" under your computer Network settings. This is a shared folder
so it will be located under the Network settings like a shared computer.
Choose any available driver letter here
Any drive letter like "R" in the example will work!
Once the shared folder is mapped to a drive your "My Computer" will have another drive listed as
"R". The drive is actually the sub folder named "RealSky
Data" containing all the RealSky data. Now, using the Digitized Sky Survey
Setup dialog you enter this mapped drive letter, "R" in the
example, in the CD-ROM drive letter box as shown.
Select the "mapped" drive letter here
Browse the computer for the location of the "Headers" folder (CCDSoft
only)
Note: RealSkyView does have the ... Browse button
shown above. See below,
Type in the drive and path of the Headers folder
Select Best Plate
The Headers folder must be copied from the RealSky South CD
labeled V. That is "V" as in Victor, the one that has the
"Copyright 1997" on the front.
IMPORTANT: The North version in the blue box disc V does not have the
correct headers for the whole night sky, only the Northern Hemisphere!
102 CD-Rom Palomar Sky Survey users
Choose the option "Low
compression (requires the 102 CD-ROM Digitized Sky Survey)". See below.
102 CD-ROM users!
Place check mark here
AND
also copy the low compression "headers" from the CD-ROM labeled #102 on to your hard disk
and set the headers path accordingly.
DSS - 102 CD-ROM set
Copy headers from CD-ROM #102
When you have specified the drive letter and location of the
headers folder you are done. At this point make sure that CCDSoft or
RealSkyView can create a DSS image on its' own before attempting to use
TheSky. This can be done easily by using the Target Lists distributed with
RealSkyView or CCDSoft.
For example Target list "Disk1.LST" has all the NGC and IC objects
found on CD Rom #1. Just use the Digitized Sky Survey | Target List option
to "View" any of the objects in list. Because all
of the RealSky data is on the hard disk you will not have to be concerned with
the CD-ROM numbers. Select target and choose "View". If
your dialog differs from the one below use the "Advanced" option to
show the additional features.
Press View
Make sure you can create the image
Next load the Target List from one of the Southern CD's like
Target list #18. This way you know that you have the proper headers from
the Southern install disc V. If you cannot create images from the Southern
CD's 9-18 you do not have the correct Headers folder from the Southern CD.
Make sure you have copied the Headers folder found on the Disc V with the "Copyright 1997" notice on
the face of the disc it as described above.
How to Create DSS images in TheSky
Also see the following step-by-step example
TheSky manual has details on how to create the
DSS images and the CCDSoft manual as details on the DSS setup. Provided CCDSoft
or RealSkyView is already able to create the images on their own then in TheSky you can create the
DSS
image by using Tools | Image Link | Create Digitizes Sky Survey Image. Or
just use the Image Link Tool Bar. If the tool bar is not visible it can be
shown using View | Tool Bars | Image Link. Note the tool bar is the
handiest way to easily create the images from the RealSky Data in TheSky.
Image Link Tool Bar
Press the Camera Icon
Just press the camera icon highlighted above on the Image Link
Tool Bar to create a DSS image for anywhere in the sky. The DSS image can
be toggled on/off or even edited using the tool bar buttons.
M51 DSS image created by TheSky & RealSkyView
One mouse click creates the DSS image
RealSky/DSS data
copyright
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. contact the Software Bisque Support Corner for
upgrades.
FAQ's:
How can I find the planets in the images
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
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 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.
RealSky North distribution using RealSky North SDB
Northern data cut-off at ~15 degrees declination
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!
Please contact the
Software Bisque Support Corner
if you have questions.
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