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RealSky Hard Disk AccessSystem Requirements
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. RealSkyView UsersTo 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. CCDSoft UsersNote: 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 optionsBecause 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/METhere 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/VistaFortunately Windows NT/2000/XP/Vista do not impose the same limitations when using the RealSky data that Windows 98/ME do. 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 Creating a Partition NT/2000/XP/VistaWarning: 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 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 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 driveUsing 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/XPNext "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 "Share this folder" as shown 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 Mapping a drive letter to a folder NT/2000/XPTo "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" 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 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 Note: RealSkyView does have the ... Browse button shown above. See below, Type in the drive and path of the Headers folder 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! 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 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 NGC 103 from the list! 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 TheSkyAlso see the following step-by-step example How exactly do I use the RealSky data and TheSkyTheSky 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 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 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 Pluto located on the DSS dataCan 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 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 No Image Found to ExtractIf 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! Can't Find Image with Proper CD InsertedIf 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. |
