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GORT Operator Instructions

The responsibilities of a GORT Operator

GORT Operators are responsible for starting up and shutting down GORT. Certain operators will often agree to be responsible for GORT on a particular night of the week. If it is your night to operate GORT, and if the weather is clear, you are responsible for opening up the observatory and preparing the telescope before sunset. You must then shut everything down 30 minutes before sunrise. Your observing mode will affect how you accomplish these tasks. In the event that you manually observe, or observe with ACP, you are still responsible for starting up and shutting down during the designated times.

If you do not have a special observing plan in mind for your time on GORT, you should start Skynet and leave it running throughout the night. This helps accomplish two major goals for GORT. The first is ready coverage of GRB. With Skynet running GORT will chase GRBs. The second goal that Skynet helps us accomplish is helping other people and organizations to collect data remotely with our facilities.

Click on the headings below to toggle open detailed instructions for operations of starting, running and shutting down the observatory. An additional click will close the instructions. The headings are indicated by a small arrow directly to their left.

Startup Instructions for manual or manual remote operation of GORT

expand section 1. VNC to the GORT control computer (64.42.103.91)

VNC is an application that allows you to remotely control a computer over the Internet. There are many VNC clients available for free download. You can download RealVNC Viewer, a free VNC program, by visiting http://www.realvnc.com. There are versions for Windows, Mac OS and Linux. Download and install the version for your architecture and then follow the instructions below to connect to the observtory.

Connecting to the GORT Control Computer (Lothar) with VNC from Windows:

Start > Programs > RealVNC > VNC Viewer > Run VNC Viewer

A window will open up for you to type the IP address into. Enter the address above and click OK. You will then be prompted for a password. Enter the appropriate password and click OK. You should then see a remote view of the GORT Control Computer desktop. You are ready to begin to operate the observatory.

Connecting from Mac and Linux

The RealVNC viewer for the Mac and Linux works as above. Just start it up and enter the login information when prompted.

There is a popular VNC viewer for the Mac called Chicken of the VNC. However, the software does not support encrypted connections, so it will not work to connect to Lothar.

Mac OSX versions 10.4 and higher have a remote desktop client built in. However, this software does not support encrypted connections to VNC hosts, so it cannot be used. Use the RealVNC Viewer as described already.

After you have a connection you will have to get an audio-video connection started. There are two ways to do this, one using the Justin.tv streaming service, the other using Skype. The sections below descripe how to create these connections.

Using Justin.tv to Get An A/V Feed*

Justin.tv is a social networking company that streams A/V across the Internet from computer video cameras. The GORT control computer, called Lothar, has a camera connected via USB. This camera can be used to watch the actions of the dome and telescope through a web browser. To start the feed, open up a web browser on Lothar (Not on your local computer - you do not want to stream yourself to the web as you open the observatory). Generally we use Chrome, but any browser should work. Open the browser using the pointer on the desktop, assuming it is not already open. Point the browser to http://www.justin.tv/. Click on the Sign In button at the top of the page (it is possible that you will already be signed in... You will see the inside of the dome displayed if you are). The login information is:

  • Login: gtn_pix
  • Password: SagA*

Once you log in, you will see a red box in the upper right of the screen that says, "Go Live." Click this. You will then see a button asking for permission to access the webcam on the computer. Allow access. The image from the camera should then be displayed after a delay (which can sometimes be fairly long). A large text button that says Start will appear on the screen. Click on that. The server will then start streaming the signal from the camera. Sometimes it can take quite a while for the broadcast to begin, so be patient. If it asks what you would like to call your broadcast, just click the "x" to close the window. We do not have to call the broadcast anything. Justin.tv changes their interface fairly frequently, so you might have to improvise somewhat on these instructions to get things running.

After your broadcast begins you will be able to view it from your local machine. Open a web browser (now it must be on your local machine) and point it to http://www.justin.tv/gtn_pix. You should see and hear the inside of the dome. Sometimes the sound will not come up. This generally only happens when the network traffic is heavy. Stopping and restarting the broadcast from Lothar will usually fix the problem. During the hours when we operate the observatory heavy traffic is rare. You should not see this problem occur frequently.

In rare cases restarting the broadcast will not fix the sound. You will have to reboot Lothar before the sound is restored. Before you reboot, be sure to shut down all the running applications, otherwise, the computer will pause during the shutdown process and ask if you would really like to shut them down. Unfortunately, this pause happens after network connections, and thus your VNC connection, have been terminated. As a result, you will not be able to reply to the query, and the computer will sit there forever waiting for you to do so. If this happens, despair not. You can reboot the computer by cycling power using the SecureLinx Power Manager. Just turn the computer outlet off, wait about five seconds, then turn it back on. The computer will reboot when power is restored. You will then be able to reconnect as soon as the boot process completes.

Using Skype to Get An A/V Feed

If you would prefer, you can use Skype to monitor the telescope and dome. This requires the gtn Skype user to be among your Skype contacts. Start the Skype program on Lothar (icon is on the desktop). Also start a session on your local machine and initiate a Skype connection from there to global telenetwork by clicking on the button with the green telephone icon on it (see below if you do not have Skype installed). When you see the call come in on the Lothar screen, answer it (you can call from Lothar to your local machine if you prefer). You must have speakers on your local machine so that you can hear the sound over the Skype connection. You should also be able to see video from inside the dome.

Once you have opened the AV connection using either Jultin.tv or Skype and you have sound (and hopefully video) you are ready to move on to the next steps. However, and this is very important, YOU MUST BE ABLE TO HEAR WHAT IS GOING ON INSIDE THE DOME BEFORE YOU ATTEMPT TO OPEN THE SHUTTER. IF YOU CANNOT HEAR SOUNDS FROM INSIDE THE DOME DO NOT ATTEMPT TO OPEN UP.

Installing Skype

If you do not have Skype installed, you should download and install it. Skype is Voice over Internet software available for all common computer platforms (Linux, Mac OSX, Windows). It was originally designed to make phone calls over the Internet from one computer to another. It is ideal for creating a monitoring connection to GORT. After you have installed Skype you will be able to "call" the GORT control computer and monitor vital operations like opening and closing the dome. When you first install Skype, you have to create an account and at at least one contact... The GORT control computer. To do this, start up the program and select the Contacts > Add A Contact menu item (the location of the menus will depend on which OS you are running). You will get a dialog box in which you can enter names to search for on the Skype network. Enter Global Telenetwork (case does not matter). It will appear after a moment in the text box below. Select it and click the Add to Contacts button. You can now make a call to the GORT control computer, as described above.

One additional point about Skype: Be sure to edit your privacy preferences so that you can be seen and contacted only by people in your contact list. If you do not do this you might find yourself being contacted by complete strangers who wish to start up a conversation. This can be annoying. If you restrict your visibility, people can still send you a message requesting they be added to your contacts, but you have the ability to refuse.

expand section 2. Turn on the telescope equipment

Power for all the telescope equipment is controlled by a remote power relay system that can be used to turn on and off different components of GORT. The power on/off switches are controlled via a web interface. The web address is https://64.42.103.92. This will connect you to the Secure Linx power manager. You will be asked to log in. Upon successful login you will see a listing of systems in the observatory (on the left) and their current power states (on the right). The table will look something like the following:

Image of SecureLinx SLP Power Manager Webpage

There is a global power control at the very bottom of the table, but you should ignore that.

To change the status of one of the outlets, use the Control Action pull-down menu (far right). To turn on an outlet, make the action On. Do this now for the Paramount, CCD Camera and Filter Wheel and Focuser. When you have changed the Action Control for all of these to On, hit one of the Apply buttons inside the table (bottom or top of column 1). This will provide power to all those outlets, causing the corresponding equipment to power up. The table will reload and show the new state in the Outlet Status column. If some of the status boxes that you changed do not say On, hit one of the Refresh links (bottom or top of column 3) to reload the page. The changed status boxes should now show On. If they do not, repeat the procedure; it could be that not all the Action Control settings were correct the first time.

UNDER NO CIRCUMSTANCES SHOULD YOU TURN OFF THE POWER FOR THE NETWORK. IF YOU DO, YOU WILL LOSE CONTACT WITH THE OBSERVATORY AND WILL NOT BE ABLE TO RESTORE IT. SOMEONE WILL HAVE TO PHYSICALLY GO UP THERE TO RESTORE CONNECTIVITY. On the other hand, sometimes the IP addresses of the camera or computer are lost. REBOOTING the network hub using the power controller can sometimes restore the IP address. You should cycle power on the errant piece of hardware first though, as cutting power to the network hub runs the risk of completely losing your connection to the observatory. If power to the network does go down and cannot be brought back up, call the observatory director immediately: 707-540-5495.

expand section 3. Connect to the camera and filter wheel

MaximDL CCD

The camera and filter wheel are controlled with the MaxImDL/CCD image processing and CCD control application. We use a Johnson/Cousins five filter wheel system. Our filters include blue (B), green (V), Cousins red (Rc), Cousins infrared (Ic), and clear (Clear). To connect to the filter wheel open MaxIm by clicking on Start > MaxIm DL. Type Ctrl-W to open the CCD Control Window, or use the menu button in the main menu of the MaxIm DL window. Once open, select Connect under the Setup Tab.

expand section 4. Turn the Camera Cooler On

Our CCD imaging camera is equipped with a 2 stage thermoelectric cooler. The cooler serves many purposes but the most important is to minimize the amount of free electrons on the CCD imaging plane. Free electrons can become trapped in the quantum wells that represent the pixels of the image read out by the camera. These trapped electrons show up as *salt* and *pepper* sprinkled on the image and must be removed by performing a dark frame calibration after the images have been taken.

The camera has a set point which is the target temperature to be reached by using the TE cooler. Our camera is generally set at -20C, but the cooler is capable of bringing the CCD to 40C below ambient, whatever that may be; if you want to change the set point, you can do so using the Setups tab in the CCD Control Window. You can image when the camera is not at the target set point, but you should not collect scientific data before the camera has reached its target set point.

MaximDL Cooler On

To turn on the TE cooler under MaxIm click the Setup tab of the CCD Control Window. Click Cooler On to turn on the thermoelectric cooler.

expand section 5. Connect to the Paramount from TheSky

Connecting the Sky to the Paramount

The telescope mount (Paramount) is controlled using TheSky astronomy software. TheSky allows us to connect to the mount and control the telescope motion. Open TheSky by clicking on Start > TheSky6. Under TheSky on the Telescope menu select Link > Establish. The application will connect to the telescope and send it to its home position at an hour angle of -2 hours and 0 degrees declination. If the telescope does not automatically home you must do so by selecting on the Telescope menu Options > Find Home.

Once again, sound is key here. When the telescope has successfully found its home position you will hear six tones. Three are for the RA axis and three are for the DEC axis. The tones vary slightly in pitch. Sometimes they overlap, but other times there can be several seconds of delay between the first three tones and the second three.

expand section 6. Connect to the Paramount with MaxIm (Optional)

TheSky has a control language that allows other applications such as MaxIm to control the telescope. This control language is often referred to as ActiveX, COM, or more generically hooks. To access these hooks TheSky must be running and the telescope must be connected to TheSky; once this is done you can connect to TheSky with Maxim DL/CCD. To connect to TheSky with Maxim, bring Maxim into the foreground and type Ctrl-T. The Telescope Control Window will open up (again, you can use the main menu item if you wish). In the Telescope Control Window click the Setup tab > [Telescope] Connect. If the connection is successful you may then click the Telescope tab and see the current RA and Dec of the telescope. At this point the telescope is connected to Maxim.

You can use the Telescope Control window to slew the telescope to different objects. Using the telescope tab you can type in the desired target coordinates in the form of "hh mm ss.sss" and "+/-dd mm ss.sss". Remember that all coordinates must be entered in J2000 epoch. While Maxim is connected to TheSky the coordinates of the object being imaged will be written to the FITS header of the image. This is extremely important to other people who might want know what objects were imaged during data collection.

You can also use MaximDL to "nudge" the telescope by small increments. Use the buttons labeled N, S, E, W, NW, NE, etc. You can set the amount of movement in the text box, and you can set the units to degrees, minutes or seconds of arc using the pull down menu. The telescope is generally set to take a 1 second image following each nudge, so you will be able to see the results of the motion. One thing to keep in mind is that when the telescope is pointing west of the meridian you should use the movement button which is the same as the movement you desire. So, for instance, if you want an object in the field to move to the left, use the W (leftmost) button. If you want an object to move up, use the N (topmost) button. When the telescope is pointed to the east of the meridian, these directions reverse. The field of view of the telescope is about 12 arcminutes. Also, the movements can be different from what you expect when you point close to the pole, so some practice with this method is generally helpful.

expand section 7. Open the dome

STOP!! Only move the dome if you have a visual connection through the webcam. Seeing the dome move is a vital check to make sure that everything is working as expected. Generally we do not have problems with our Astrohaven dome, but it is better to be sure; don’t just assume that what the computer display is telling you is accurate.

Open the Logitek Webcam Software. The software is generally running and on th Task Bar. If it isn’t there you will have to start it from the Programs menu item. Look for the Logitek menus. Once the software has openned you can get a view from the webcam by clicking on the second icon from the top. It looks like camera film. That will open a window with a live feed from the webcam.

To open the dome you must currently use a terminal process. There is a dedicated terminal process located on the Destop. It is a ared telephone icon called Dome.ht. Open the process by double-clicking the icon. In the terminal type the letter "a" repeatedly. You should see one half of the dome shell begin to open. Continue to type "a" a return code of "x" is displayed on the terminal line. That indicates that half of the dome is fully open. Then type "b" repeatedly until a "y" is displayed. You should see the other half of the dome shell opening, and the appearance of "y" will indicate that it has fully opened.

Once both sides of the dome are open you can close the terminal process and close the camera display. Generally we leave the Logitek software running but minimized. Just be sure the camera display window is completely shut down, as the video feed requires a lot of bandwidth.

The Dome is now open and ready for the night’s observing. If you wish, you may pre-position the telescope to Alt=70, Azim=90 for the acquisition of twilight sky flats.

expand section 8. Take calibration images

If you will be observing manually, now is when you should make your calibration files (Skynet takes its own calibration images, so if you are openning for a Skynet session you can skip this section). You will need darks, biases and flats. The Darks and biases can be done at any time after the camera is cool. The same is true for dome flats. For twilight flats you will obviously have to wait for twilight. See the section at the bottom of the page on taking calibration images.

expand section 9. Focus the telescope

This section will describe how to focus the camera and then set up the temperature compensation so that the camera remains in focus as the telescope contracts through the night in response to decreasing temperatures.

If you plan on taking dusk flats as outlined in the section labeled "Acquisition of Calibration Images with GORT", below, you will have to proceed to that section and complete dusk flat acquisition before focusing. Focusing should be done when the sun is between about 10 and 18 degrees below the horizon. Dusk flats should be started when the sun is 3 degrees below the horizon. They will end when the sky becomes too dark, when the sun is around 7 degrees down. Ergo dusk flats should be done before focusing.

Focus of a telescope varies with temperature because the telescope contracts and expands as the temperature falls and rises. If the temperature of the scope changes appreciably between observations the focus will change. If the focuser has not been set up to compensate for the thermal expansion and contraction of the telescope, it will cause the seeing disk of the stars to increase. Extended sources will appear out of focus. A change in temperature of 5 degrees can cause the seeing disks in our images to increase by more than 50%. Because of this we have to focus the telescope each night to create pinpoint stars. Furthermore, it will be necessary to compensate for the temperature changes through the night.

GORT uses an application named FocusMAX to focus the system. On the back of GORT between the telescope tube assembly (the big round tube) and the filter wheel is a Cray style autofocusing tool. It works by moving the camera forward and backward relative to the telescope optics. This allows the camera to be moved into the focal plane of the telescope.

FocusMAX Window

Focus the Telescope
Open FocusMAX by clicking Start > FocusMax. You should manually point the telescope to a star of between 5th and 6th magnitude. By default TheSky is usually set to only display stars between 5th and 6th magnitude. Sometimes this setting gets changed, but if not you can select any convenient star in the display of TheSky. Be sure that the exposure time (on the Exposure tab of MaximDL) is set to about 0.6 seconds and the filter is either V, Ic or Rc, then hit the Focus button on the FocusMax window. Alternatively, press the Acquire Star button. FocusMax will then automatically choose a suitable star and focus the telescope. Be sure that the star was not saturted during the focus session - in the Inspect tab of MaximDL saturted stars have a flat top. If the star does saturte, decraese the exposure time slightly and try to focus again. Once focus is obtained, turn on temperature compensation to maintain it, as described next.

TCF-S Window

Turn on Temperature Compensation
You should turn on the temperature compensation as soon as you can after performing a focus because until you do any temperature change will degrade focus.

Shut down FocusMAX and start up the TCF-S temperature compensation program: Start > TCF-S.exe. A window will appear asking you to choose a COM port. Click "ok" and then when the main TCF-S window opens go to the Setup menu and choose COM port 11: Setup > Select COM Port > COM11. Then connect the temperature compensation to the focuser: File > Connect. In the Mode window in the bottom center of the window, choose Auto-B. You should now minimize the window. The TCF-S software will keep the camera in focus as the telescope responds to temperature changes through the night.

I usually open up the TCF-S window before starting FocusMAX to save a little time. I select the COM port but do not connect to it (TCF-S and FocusMAX cannot both be connected to the focuser at the same time). Then after I focus I have only to shut down FocusMAX, connect TCF-S and set it to Auto-B. Since the temperature does not generally change extremely rapidly, this method is not absolutely necessary, it is just how I do it.

expand section Startup complete

At this point you have successfully completed the startup of GORT for manual remote operation. You can begin your observing program.

Startup of GORT as a Skynet Node

Skynet currently does not support automated control of GORT dome. Because of this GORT operators must perform some of the tasks that terminator normally takes care of. These tasks include opening and closing the dome at the appropriate time as well as have the equipment properly connected and terminator running at the appropriate time. It you are unable to perform these tasks at there designated time you must manually collect the required calibration images.

Skynet incorporates in it the ability to capture its own calibration files. However, for this to work the equipment has to be ready to go at the right time.

expand section 1. Perform steps 1 - 6 in the section titled "Startup Instructions for manual or manual remote operation of GORT".

This step should be completed before the sun reaches and altitude of +10 degrees. Use your favorite software package to determine when the sun will be at an altitude of +10.

Do not perform steps 4, 9, and 11 in the section titled "Startup Instructions for manual or manual remote operation of GORT".

DO NOT OPEN THE DOME AS INSTRUCTED IN STEP 7.

DO NOT SLAVE THE DOME TO THE TELESCOPE IN STEP 8.

DO NOT ATTEMP TO FOCUS THE TELESCOPE. Focusing the telescope with the sun up and the dome closed is unlikely to produce favorable results. ;-)

expand section 2. Point the Telescope due East

With the dome closed select a spot in TheSky with azimuth 90 and altitude 70. To make this easier, turn on the red grid for the Alt-Az coordinate system by clicking on the small red grid button in the control panel of TheSky - the blue grid button turns on the Celestial coordinate system (RA, DEC) which is definitely not what you want here. When the Alt-Az grid appears, click on the appropriate coordinates and then slew the telescope there by clicking the green telescope icon in the Object Information window. The purpose of this is to allow you to open the dome while the sun is still above the horizon. In addition, this is the point where Terminator will move the telescope when taking twilight flats, and by pre-slewing the telescope you save a little time at twilight. Once you have moved the telescope use the button on the control panel to toggle the grid display off.

expand section 3. Open the dome

See Step 7 in the Startup Instructions for manual or remote manual operation, then return here when completed.

expand section4. Startup Terminator to begin calibration image acquisition

On the Start menu select Terminator. Terminator is the program that connects to the Skynet telescope networking system and receives requests for observations by GORT.

expand section5. Confirm that Terminator is Properly Connected to the camera, the telescope, and Skynet

Digital Dome Works Window

Confirm that Terminator reports the following under the Status tab; Mount State should read IDLE not ERROR, Camera State should read READY not ERROR, and Skynet Connected and Site Permission (bottom of box on right hand side) should both be "illuminated," as shown in the image. Note that Cooler on and Cooler at setpoint are not illuminated in the image. They turn on when the cooler is turned on and after the camera reaches its set point, respectively.

If any of these items reports an error, close Terminator and restart it. To close Terminator you have to click the small "x" in the upper right corner of the Terminator window. A small window will appear asking if you would like to close the dome. The box to do so will be selected: de-select it, then say "OK." This will put the Terminator program into a suspended mode, but the window will not go away the program is not stopped. Click the "x" again to close the window and shut down the program.

Shutting down Terminator might not fix the problem. If not, close Terminator and reinitialize the system that reports the error, then restart both. For instance, if you have a problem with the mount, close Terminator, home the mount (sometimes you might even have to cycle the power to the mount, but usually not), then restart Terminator. If the problem is with the camera, close Terminator, shut off the camera, then restart the camera and Terminator (in that order). If asked to turn off the camera cooler select no because it takes approximately 20 minutes for the cooling process to cycle.

If these steps do not bring the sytem up without errors, contact the observatory director at 707-540-5495

expand section6. Grant Access to Skynet to make requests on GORT

Visit https://skynet.unc.edu/ and login using your username and password. If you do not have a username and password contact the observatory director. Select site manager on the menu at the top of the page. Change the permission field from Denied to Granted. Click the Change button.

At this point GORT should function as a Skynet node. You can make observation requests on GORT or any other telescope in the Skynet network on the SkyNet website at UNC

expand section7. Wait for Terminator to finish collecting darks, biases, and dusk flats

Terminator will collect biases and darks while the sun is still above the horizon. Once the sun reaches and altitude of -3.5 degrees it will begin collecting flats. This will continue until the sky becomes too dark to collect flats, or all the required flats are captured. In either case Terminator will appear idle for several minutes. This is your indicator that flats have been acquired.

expand section8. Close Terminator.

To shutdown Terminator click the red and white X in the upper right corner of the Terminator window. Deselect the option to shut the dome or turn off the camera cooler. Click Ok. Terminator will not close it will simply stop operating. Click the close button one more time to exit the application.

expand section9. Focus the telescope

Terminator turns tracking off while not imaging. To focus you must turn tracking back on. Under TheSky select Telescope > More Options > Tracking so that tracking is checked.

Focus the telescope as described in Section 9 of the Startup Instructions for manual or manual remote operations, above. Return to this flow to complete the Skynet startup after you complete the focus procedure.

expand section10. Restart Terminator, Confirm that It is Properly Connected

Digital Dome Works Window

Confirm that Terminator reports the following under the Status tab:

  1. Mount State should read IDLE not ERROR
  2. Camera State should read READY not ERROR
  3. Skynet Connect light should be green.
  4. Site Permission light should be green.

If any of these items reports and error shutdown Terminator and restart it. If that does not fix the problem, shut down Terminator and the offending system and restart both. For instance, if the problem is with the camera, make sure both the camera and filter wheel are on. If they are, restart them and then restart Terminator. Ditto for problems wth the mount. If asked to turn off the camera cooler when restarting the camera select no because it takes approximately 20 minutes for the cooling process to cycle. If none of these steps fix the problem, call the observatory director at 707-540-5495.

expand section11. Startup Checklist

The system should now be ready for robotic observing. As one last check, be sure that each of the following is true:
  1. Camera is focused and temperature calibration is turned on.
  2. Camera is at setpoint, -20C.
  3. Telescope is at Home position, or pre-positioned for sky flats.
  4. Dome is open.
  5. Terminator is turned on (after Homing and slaving), no errors are indicated and site permission is granted.
  6. Light in the dome is turned off.

If all these items check out okay, the observatory should be fine on its own for a night of observing.

Shutdown of GORT as a Skynet Node.

expand section1. Close Terminator.

If calibration sequences are complete you can shut down Terminator. Click the red and white X in the upper right corner of the Terminator window. Deselect the option to shut the dome or turn off the camera cooler. Click Ok. Terminator will not close it will simply stop operating. Click the close button one more time to exit the program. Be sure to wait until Terminator has completed its calibration sequences (biases and darks) before closing it.

expand section2. Proceed to Step 1 in the section entitled Shutdown Instructions for GORT.

Shutdown Instructions for GORT

expand section 1. Close the dome

STOP!! Only move the dome if you have a visual connection through the webcam. Seeing the dome move is a vital check to make sure that everything is working as expected. Generally we do not have problems with our Astrohaven dome, but it is better to be sure; don’t just assume that what the computer display is telling you is accurate.

To close the dome, use the same terminal process you used to open it - the red telephone icon on the Destop labeled "Dome.ht." Open the process and type "A" repeatedly until the terminal displays an "X." You should one side of the the the dome swing closed. Repeat the same steps, but type "B" until you see a "Y" return value displayed. The other side of the dome will swing closed. Confirm that the dome is closed in the webcam display.

Sometimes the terminal will indicate that the dome had closed, but you can see that it hasn’t. If this happens, type "a" or "b" as appropriate to fully open the misbehaving side of the dome. Then close as described above. Usually, opening the troubled side of the dome in this way will allow it to close properly.

expand section  2. If ACP is connected to the telescope, dome, and camera, disconnect.

If ACP is connected to the telescope, dome, and camera, we have to disconnect it. Using VNC to view the GORT control computer terminal, bring ACP to the foreground. Under ACP click Telescope > Disconnect and Camera > Disconnect. Proceed to step number 4.

expand section  3. If Skynet is connected to the Telescope, disconnect

If Skynet is connected to the telescope and camera we have to disconnect it. Using VNC to view the GORT control computer terminal, click on the "x" in the upper right of the Skynet window frame. When the dialog pops up asking about closing the dome, etc., make sure that both boxes are deselected, then click "OK." This will put Skynet to sleep, but will not stop it. Wait a few seconds for the program to go to sleep. When the process is complete the window will reposition itself slightly to the upper right. Click the "x" again to close the window and kill the program. Proceed to step number 4.

expand section 4. Turn the dome illumination light back on (Optional)

Bring up the web interface for the Secure Linx power manager. If you have previously logged out or shut down your browser since opening up, log on to the power manager. If it is dark out, use the power manager to turn the light on by setting the Control Action for the Light to On. Hit the Apply button.

expand section 5. Start warming up the camera

MaximDL Warm Up

Under MaxImDL open the CCD Control Window (Ctrl-W). Select the Setup tab and click Warm Up.

Do not disconnect the camera or turn off power to the camera until the Cooler indicates the cooler power is at 0%. FAILING TO WARM UP THE CAMERA PROPERLY WILL DAMAGE IT.

expand section 6. Park the telescope

In TheSky, click Telescope > Options > Park. Be sure to watch the telescope progress back to the park position in which you found it. When the telescope is parked it should point due-South right at the horizon. TheSky has crashed once or twice during the park maneuver, though this is rare. If the telescope starts to point below horizontal quickly click the Abort button in TheSky. Reestablish a connection with the telescope, send the telescope home, and then attempt to repark the scope. In the event that the telescope hits the ground contact the observatory director at (707) 540-5495.

Parking is not absolutely critical, so if you have trouble parking the scope (short of running it into the ground), just close the dome and send an email to the observatory diretor about the problem.

expand section 7. Disconnect from the camera in MaxIm

MaximDL Warm Up

WARNING!!! Do not disconnect the camera or shut off power to it until it has completed its warmup cycle (Step 5). Failure to warm the camera properly can damage it.

Bring MaxIm to the foreground. If the camera has completed its warmup cycle (cooler power is at 0%), click the Cooler Off button and then the Disconnect button from the CCD Control Window Setup tab. Exit MaxIm. (File > Exit)

expand section 8. Turn off the TCF-S Temperature Compensation (Optional)

This step is optional. If you leave the program running and the focuser powered up then the focus will be maintained from night to night. This saves time. However, sometimes it is necessary to shut down the focuser for some reason, for instance, if the temperature will be very hot during the day. Follow these steps if you need to shut down.

Bring the TCF-S window to the foreground. Switch the mode to Manual. Click File > Quit. When prompted whether or not to exit click YES.

expand section 9. Power off the equipment

Use the Secure Linx power manager to shut off power to the Telescope, Camera and Filter Wheel/Focuser (shutting down the focuuser will cause it to lose focus, so if you want the TCF-S software to be able to maintain focus you must leave the focuser powered up). If the light in the dome is on, turn it off as well. See Step 3 in Startup Instructions for manual or manual remote operation of GORT for instructions on using the power manager. The table should look as depicted there. UNDER NO CIRCUMSTANCES SHOULD YOU TURN OFF THE POWER TO THE NETWORK OR THE CONTROL COMPUTER.

expand section 10. Shutdown complete

At this point the system is powered down and also in the exact state in which you found it. There should be three applications running: Weather Capture, Boltwood Cloud Sensor and Clarity. If any of these are not running (they could be minimized, so look for them on the Task Bar), open them as necessary.

Acquisition of Calibration Images with GORT

There are three types of calibration images that must be acquired each night GORT is used to collect scientific data. These three types of images are bias, dark, and flat images. Maxim Sequences have been set up to make collection of calibration images as simple and standard as possible.

expand section1. Specify "calibration_" as the Autosave Filename

With the telescope and imaging equipment on, and with the camera cooled, select the Sequence tab from the CCD Control Window. Type "calibration_" in the Autosave Filename text field. Maxim DL will prepend each image file name with this string when it saves the images to disk.

expand section2. Load the appropriate calibration sequence.

Click the options button and select Setup Sequence. Click the Options button in the Setup Sequence window and select "Load Sequence...". There are two sequences that can be used. One is designed to for collecting dusk sky flats. The other is designed for collecting dome flats. To collect dome flats specify "C:\Documents and Settings\gtn\My Documents\Sequences\flat_field_calibration.seq" as the sequence file. To collect sky flats specify "C:\Documents and Settings\gtn\My Documents\Sequences\sky_flat_sun_minus_3_degree.seq" as the sequence file.

expand section3. Activate the Group by Slot option

Under the Options button click and check the Group by Slot option. This will collect all the images of a particular type in a row as opposed to going trough the whole sequence once and then repeating as specified.

expand section4. Modify the Sequence as needed

Based on the observations for the night you can disable or modify the calibration sequence to meet your needs. However, do not save your changes to the original file. Here are some things to keep in mind while setting up your sequence.

  • You need flats for every filter and every binning that was taken for the night.
  • Changing the binning will effect the exposure time required to prevent flats from being over exposed or under exposed. The number in each file are preset for a binning of one.
  • The exposure time for your dark images must be at least as long as your longest exposure.
  • Do not capture an exorbitant amount of calibration frames. A 1x1 image is approximately 2 Mbytes in size. Taking 100 two MB images is 200 Mbytes. This rate of disk space consumption will eat up GORT hard disks very quickly. Please only get what you need for the data that was taken that night

When your sequence is complete click the Ok button in the Sequence Setup window.

expand section5. Specify a location for the calibration files

Select the Options button on the Sequence tab of the CCD Control window. Select Set Destination Path.... All GORT data is stored in C:\data. Create a folder in the data directory for the data that will be taken that night. The name of the folder should be in the format of YYYY-MM-DD. (For example, 2006-05-01). The date should be the local date at the start of the observing run. Do no vary this format or leave off leading zeros!

At this point the steps you take to acquire your calibration frames change depending on which method of flat acquisition you choose. Please use the instructions listed below for the flat acquisition method you choose. When you have you sequence set up click "Ok." Also, you might want to read the page on obtaining calibration images to get an idea of what these images are for and to learn a few strategies for making them.

Dusk Flat Instructions

These instructions should be executed 15 minutes before sunset

1. Complete steps 1-5 in the section titled "Acquisition of Calibration Images with GORT"

expand section2. Slew the telescope to the East at an altitude of no less that 70 degrees.

In TheSky click on an area due East that is within 20 degrees of the zenith. Click the green Slew button in the Object Information window and confirm the slew.

expand section3. Turn telescope tracking off

Under TheSky open the Telescope Menu and select Telescope > Options > Tracking so that the Tracking option is unchecked. Be sure to reopen this menu and confirm that tracking is off.

expand section4. Wait until the Sun has set

In TheSky, open the Tools menu and select Tools > Sun & Moon Report. Identify the local time that the sun will set. Add 4 additional minutes onto this time and that is when you should start your sequence.

expand section5. Start the Sequence

Select start from the Sequence tab of the CCD Control window.

If everything is set correctly your calibration images should be acquired. Be certain to carefully observe each flat as it appears. Make certain the ADU counts are under 60000 and above 30000. Saturated flats are not useful, and flats with too few counts will decrease the worth of the data that was taken for the night.

expand section6. Turn telescope tracking back on

Under TheSky select Telescope > Options > Tracking so that tracking is checked (on). Be sure to double check that the tracking is, in fact, turned on.


If you have a question about the GTN, please contact one of the "Responsible SSU Personnel" below.

This page was last modified on Monday 01st July 2013 @ 13:33pm

Science Mission Directorate Universe Division

Responsible SSU Personnel:

Dr. Kevin McLin (mclin at universe dot sonoma dot edu)

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