The telescope as well as the rotation of the dome allow for remote computerize control. Information about the operational process used to control the observatory remotely is detailed here. For the most part the standard mode of operation of the dome rotation and main telescope are operated under remote computer control. The local PC that actually controls the dome rotation, telescope positioning, CCD imaging as well as the Flat Fielder light box is a Medion 2.4 Ghz Celeron running Windows XP Pro.
The observatory PC uses a Belkin USB to Serial converter and 3 pure RS-232 ports. These are used to control the dome, the Paramaunt ME, power strip, and the Flat Fielder light box. Two of the three RS-232 ports are a ByteRunner dual port PCI card which were added to the PC. There is also a 4 port USB hub connected to the PC that is used to interface the Canon 10D DSLR, as well as the Starlight Express MX7C CCD, Meade Deep Space Imager (DSI) and the SBIG ST-2000XM. (When the Canon 10D is used and exposures longer than 30 seconds are required the Canon 10D must also be interfaced via the parallel port in addition to the USB port.) A system interconnection diagram shows the layout. A simplified version is also available. The dome's shutters are also computer controlled via a wireless link, which can to set to open or close at user specified times. The PC that controls the shutters is the Weather Station which is also on the network.
The observatory computer resides on the local network in which any computer that has access to the network can connect to it and completely control operations This includes remote access from the Internet. The system supports Ethernet, 802.11a, 802.11b, 802.11g, Bluetooth and Home RF. Access to the observatory's PC from the local network is achieved by Microsoft's Remote Desktop server software or VNC software.
(Both the Remote Desktop server and client side software are available with Windows XP-Pro and XP-Media. Only the client side software comes with Windows XP-Home. You can download the client free for Windows 95, 98 and 98SE here. The is also a web based version of Remote Desktop that allows you control the system over the internet. The client software Remote Desktop Web Connection is a free download from Microsoft. In order to access your system via the web you will also need to have Internet Information Services (IIS) running on the host machine.)
If a user wishes remote access to the system and does not have Windows XP-Pro a program called Real VNC can also be used. The nice thing about about Real VNC is there is a version for just about every platform, Windows, Unix etc. The main draw back of VNC it is slow (compared to the Windows Remote Desktop system). But it does work well over the Internet and no client side application is needed if you use a browser that has JAVA enabled. VNC is also useful when the user is behind a firewall in which the System Administrator has block access on certain ports. It is much easier to change the access ports associated with VNC than it is with Remote Desktop Web.
The option used for remote access over the internet (and sometimes local access) is the Log Me In (LogMeIn) remote service. The package is a bit different as it use a server on the internet to provide IP address of your remote PC. This is important if the PC you wish to access has a dynamic IP address. There is a free and pro version. The pro version has a bit more features, but the free version work fine for most cases.
(No matter which one of the above programs are used, if you are going to setup a system for remote access over the Internet I strongly suggest you change the default ports used by both VNC and Remote Desktop Web. f you don't want to access your system over the Internet then you should as a minimum block the programs' default ports in your routing table.) I also suggest you use a Strong Password. This will help prevent hackers from finding their way into your system. For the LogMeIn service I suggest you not use a common email address that others have access to. I
The connection the observatory uses for Internet access is DSL. In order to connect to the observatory computer from a remote location using the internet the user must know the observatory' Wide Area Network (WAN) IP address. Since this IP address (which is assigned and controlled by the DSL provider) changes, a way was needed for a user at a remote location to know what that IP address was. This problem is solved by a program called WallWatcher. WallWatcher runs on the weather station computer and monitors the TCP/IP traffic to and from the internet gateway as well as the Local Area Network (LAN) it is attached to. It does this by accessing the router's log file. One of the features that can be enabled within WallWatcher is to report the router's status via periodic emails to a user specified email address. Contained within that status is the current WAN IP address the router is using to access the Internet. The observatory is configured to report the IP address once every hour. It will also immediately email a report if the IP address changes or the router is rebooted. This means an authorized user need only access the special email account in order to retrieve the current IP address for the observatory.
Computer control of the domes' rotation is achieved via an ASCOM compatible RS-232 hardware interface. The Sirius Dome Controller software was graciously supplied by Diffraction Limited. This control software was designed for the original Autodome board (used by the observatory) but never publicly released. (Autodome is now a discontinued product and it has been replaced by the manufacturer with Maxdome). The software allows the dome to be synchronized with the movement of the computerized telescope which insures that the dome's aperture is always in the correct location during an observation session.
(The Software Bisque's Automadome software was used at the observatory. It was replaced with the Diffraction Limited Sirius Dome Controller which uses less system resources than the Automadome software. One reason is the external wscript.exe program is not required the make the dome track the telescope. Wscript is a resource hog. While the Autodome software remains on the observatory computer it is almost never used.)
The computer connection to the Paramount ME German Equatorial Mount (GEM) is via the RS-232 port on it's base. While computer control is the primary mode of operation for the telescope, the scope can also be controlled locally by a joy equipped hand controller .
The software used for computer control of the telescope is the Software Bisque's TheSky6 Professional Edtion. TheSky6 creates a computer generated display of the viewable sky based on the user's longitude, latitude and time of day. This assists in locating stars, planets, nebulas, variable stars and other deep space objects. Once the object of interest has been selected the software issues commands to slew the telescope to the object's coordinates.
In addition TheSky6 can be switched from the computer generated display to the Digital Sky Survey, which can display single color (one pass-band) images of the entire northern hemisphere down to -15 degrees, and the entire sky south of the celestial equator. The northern images were provided by the Palomar Observatory and the southern images were obtained by the Royal Edinburgh Observatory/Anglo-Australian Observatory. Coupled with data provided by the U.S. Naval Observatory over 1/2 billion star positions can be calculated, displayed and tracked by the telescope.
For automated control of the scope and integrated automated imaging, a program called CCDsoft is used. The only cameras in use at the observatory that CCDsoft can control are the SBIG ST-2000XM, the SBIG ST-402ME, and the SBIG AllSky Meteor Cam. CCDsoft integrates with TheSky6 and Orchestrate.
Orchestrate is scripting program that can control TheSky as well as CCDsoft. It is this scripting system that allows the complete automated control of the observatory. Another scripting control program was added to the observatory, MPO Connections. MPO Connections was designed to allow automated asteroid astrometry. It also integrates with TheSky and CCDsoft and is a much more powerful program in terms of scripting and automated control, then Orchestrate. It is also easier to use. It has the ability to generate scripts that can slew the telescope to any object, like planets, stars, nebulas, galaxies, and of course asteroids. It can correct the telescope's pointing, take an image, save the image and then move to the next target. It can even be setup to wait for an object to clear the horizon, trees or my neighbor's house. At the end of the session it can park the scope and shut down the camera. Many amateur astronomers use MPO Connections for automated Super Nova searches.
The telescope can also be controlled via a HP IPAQ Pocket PC using TheSky PE. TheSky PE is a special version of TheSky software which only runs on a Pocket PC. It does not have as many feature as the desktop version, but does a good job of controlling the telescope. A Promi-SD202 Bluetooth serial adapter is used for communication between the Pocket PC and the telescope. 5 volt DC power to the adapter is supplied via one of the USB port on the USB hub. In order for the telescope to be recognized by TheSky PE software, the adapter must be programmed with no hardware, 9600 baud, and no parity.
Sometimes, two or more programs may need to access the virtual serial port used to control the shutters, dome power or focuser switchbox. The serial port used for control from the observatory was created with the Fabula Tech Network Serial Port Kit . An example of this situation occurs when the shutters need to be controlled from a scripting program resident on the observatory PC, while the observatory control GUI is open. In order for there not to be a conflict between the two pieces of software the control GUI was rewritten so it closes the com port after each operation. But the software still needs to send commands to the shutter control box which is actually attached to a physical serial port on the Weather Station PC. In order to prevent a conflict on this PC the FabulaTech Serial Port Splitter software is used. This program allows the physical serial port on the Weather PC to be shared with multiple applications able to access the port at the same time, such as when the scheduler program is running. This program opens the shutters about an hour or so before dark to allow cool down of the observatory during the summer months.
During the remote computerized operation, the telescope and dome position are monitored by three 12 volt DC powered GE SmartHome black & white video cameras. The camera's output is routed to a selector box by means of a 2.4 GHz wireless link. The selector box will accept up to 4 cameras. The selector box allows the user to manually control which camera's output is displayed, or the unit can be set to scan all of the cameras in sequence with delay interval variable from 1 to 30 seconds. The cameras feature a night vision mode in which built in LEDs are used for illumination. This allows the cameras to "see" in total darkness. This 7 meg AVI clip to shows the output of two of the cameras during a daytime 180 degree slew of the telescope.
Observatory Control GUI was written to provide remote manual control of the dome
power, dome rotation, shutters, remote controllable 120 volt AC power strip. The
power strip allows control of the Paramount ME, SBIG ST-2000XM and ST-402ME CCD
cameras, the focuser switchbox, dew heater dehumidifier and auxiliary outlet.
The Start-Up button with automatically perform the following sequence:
* Dehumidifier is turned off.
* Shutters are opened.
* The dome's rotation power is turned ON and remote dome control is enabled.
* Paramount ME (GEM) is switched on.
* ST-2000XM CCD camera is switched on.
* ST-402ME CCD camera is switched on.
* Dew Heaters are switched on.
To safeguard the telescope during remote operations it is extremely important to have a way to shut down the scope in case of an emergency. This was accomplished by clicking the "All Power OFF" on the Observatory Control GUI. There is also an emergency remote wall mounted shut down button the will instantly cut power to telescope as well as most other devices in the observatory except the lights and the 1200 watt inverter.
The Observatory PC and the Weather
Station computer are also connected to a Ethernet controller boxes. The
controller boxes (N-RRC)
are connected to relay boxes called Intelligent Auto Push Boards (I-APB).
The I-APBs are wired into the front panel power switch of the PCs. This allows the PCs
to be remotely shut down, power up or re-booted via the internet should the system hang for some reason.
Go to the JATObservatory Home page
Updated 01/19/2008 - Please report broken links email@example.com