isengard telescope orientation and operations guide isengard guide...isengard telescope orientation...

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Isengard Telescope Orientation and Operations Guide

GNTO Document #5 (GNTO-5)

26 November 2017

Document Lead: Mike Molitor

Author: David Downs & Jim Fordice

Isengard Telescope Orientation and Operations Guide (GNTO-5) (26 Nov 2017)

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TableofContents1. PURPOSEANDSCOPE........................................................................................4

2. REPONSIBILITIES................................................................................................4

3. REFERENCES......................................................................................................5

4. PROCEDURES.....................................................................................................5

5. STARTUPANDSHUTDOWN...............................................................................65.1. Access Lights ................................................................................................................................ 6

5.1.1. Stairs & Lobby ......................................................................................................................... 65.1.2. Dome Interior ........................................................................................................................... 65.1.3. Chart Table ............................................................................................................................... 7

5.2. Stairway Door ............................................................................................................................... 75.3. Dome Shutter ................................................................................................................................ 7

5.3.1. Upper Section ........................................................................................................................... 85.3.2. Lower Section .......................................................................................................................... 8

5.4. Dome Rotation .............................................................................................................................. 95.5. Telescope Tarps .......................................................................................................................... 105.6. Telescope Remote Focuser ......................................................................................................... 115.7. Telrad Finder .............................................................................................................................. 125.8. Telescope Power and Astrometric Control ................................................................................. 12

6. BASICTELESCOPEOPERATION.........................................................................156.1. Dust Covers ................................................................................................................................ 156.2. Eyepiece ...................................................................................................................................... 156.3. Tube Rotation ............................................................................................................................. 156.4. Slewing Precautions .................................................................................................................... 156.5. Aiming the Telescope ................................................................................................................. 166.6. Acquiring and Viewing the Target ............................................................................................. 16

7. TELESCOPEOPERATIONUSINGTHENGC-MAXOBJECTCATALOG.....................177.1. Align Star Mode ......................................................................................................................... 177.2. Catalog and Guide Modes .......................................................................................................... 18

8. SLEWINGTOANOBJECTWITHTHEASTROMETRICHANDPAD.........................188.1. Notes on Astrometric Hand Pad Operation ................................................................................ 19

9. TELESCOPEOPERATIONUSINGTHELAPTOPCOMPUTER.................................19

10. COMPUTERSHUTDOWN..................................................................................21


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VERSIONHISTORY.....................................................................................................22

Attachment1:ISENGARDSTARTUP/SHUTDOWNCHECKLIST.....................................23


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1. PURPOSE AND SCOPE

This document provides the procedures for opening and closing the dome of the GNTO Main Dome Building and for properly opening, operating, and shutting down the Isengard telescope. This document is the primary reference for TAAS members to learn how to operate the Isengard telescope.

2. REPONSIBILITIES

An Isengard User is a TAAS Member who has been trained to operate the GNTO Main Dome Building’s dome and the Isengard Telescope. When the Isengard user is opening, using, or closing the dome and/or telescope, the Isengard User is responsible for all activity associated with the dome and telescope. The Isengard User responsible for following these procedures.

Isengard Users are responsible for maintaining their knowledge of current Dome and Isengard operations. To do so, they are encouraged to attend periodic Isengard training classes. They are encouraged to open and operate the Dome and Isengard Telescope several times a year to maintain their proficiency.

An Isengard Trainer is a member of the GNTO Committee who has been designated by the Observatory Director to train other TAAS members on the operation and use of the dome and the telescope.

The Isengard User’s main purpose is to provide an opportunity for a safe and enjoyable experience for TAAS members and guests as they observe using the Isengard telescope.

The Isengard User must inform the Opener of their intent to use the dome and the telescope and should keep the Opener informed of dome and telescope activities. The Isengard User Operator is responsible for shutdown of the dome and the telescope and for informing the Opener when shutdown has been completed.

If the Isengard User needs to depart GNTO before all the responsibilities associated with dome and telescope operations are completed, the Isengard User is responsible for arranging for another Isengard User or the Opener to complete the shutdown operations.

The Operator should be familiar with the GNTO Emergency Procedures (GNTO-1) and GNTO Safety Procedures (GNTO-2). The GNTO Safety Procedures (GNTO-2) must be followed when using these procedures.


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3. REFERENCES

GNTO Document 1 – Emergency Procedures

GNTO Document 2 – Safety Procedures

GNTO Document 3 -- GNTO Keyholder Procedures

Additional documentation is in the green cover plastic bin on the dome level and in binders in the Computer Room.

4. PROCEDURES

This guide is organized as an opening/startup procedure. After the telescope and dome are used, they must also be shut down and closed. To shut down and close the telescope and dome, reverse the procedures.

As an aid to opening and closing, use Attachment 1, Isengard Startup/Shutdown Checklist. The checklist provides a sequence of steps for both opening and closing. To open and start, follow the sequence by reading DOWN the LEFT-side of the checklist. To shut down and close, read UP the RIGHT-side of the checklist.

When following the checklist, consult this guide for details regarding specific steps.

In this guide, it is not possible to describe every feature or function of hardware and software operation. Additional documentation is in the green cover plastic bin on the dome level and in binders in the Computer Room. Manufacturer websites may need to be consulted for troubleshooting or detailed information.

If you have questions, consult with another experienced Isengard User

These procedures assume that the Main Dome Building has been properly opened and is operating per GNTO Document 3, GNTO Keyholder Procedures.


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5. STARTUP AND SHUTDOWN

5.1. Access Lights

5.1.1. Stairs & Lobby

A timer switch is located at ground floor level on the east face of the telescope pier, in the center of the building. As shown in Figure 1, a small toggle switch is located next to the timer switch, which controls power to the LEDs on the stair steps. A second toggle switch is for the lobby area lights.

Figure 1: Stairs and Lobby Light Switches

5.1.2. Dome Interior

Red lights are in two corners of the upper dome structure. A switch located on the 2nd floor in the northwest corner (Figure 2) controls the power for these lights. The switch toggles to the right for the on position. Once the switch is in the on position the light level can be controlled by the dimmer knob. To turn off the lights, please use the toggle switch; don’t simply turn down the dimmer knob.


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Figure 2: Dome Interior Light Controls

5.1.3. Chart Table

A switch and dimmer located in upper right corner above the chart table controls the chart table light. The light can be used to provide illumination for charts at the chart table or can be used for supplemental dome illumination.

5.2. Stairway Door

Typically, the stairway door is kept closed to reduce airflow through the dome.

5.3. Dome Shutter

The dome shutter (Figure 3) has two sections. The upper section must be opened at least several inches before the bottom section can be opened. When closing-up, close the lower section first, then lower the upper section.

Figure 3: Dome Shutter


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5.3.1. Upper Section

Rotate the upper shutter hand crank (Figure 4) in a counter clockwise direction to open the upper section. Secure the crank with metal hook when shutter is open.

Important! Grip the shutter crank firmly always and secure it with the metal hook when shutter is open. The weight of the upper shutter can cause the crank wheel to spin out of control, both when opening and when closing the upper shutter.

Figure 4: Upper Shutter Hand Crank

5.3.2. Lower Section

The lower shutter section may be opened when needed to see low targets. Use the lower shutter crank wheel (Figure 5) to loosen the cables holding the lower shutter by turning counter-clockwise and then use the stick to push the shutter open until it tilts out. Continue to open the bottom shutter section until support chains are taut.

It is best to stow both upper and lower shutter hand-crank arms in the upward position to avoid collision with people and equipment when the dome is rotated.


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Figure 5: Lower Shutter Hank Crank

5.4. Dome Rotation

The dome rotates using an electric motor. The motor drive system is located at the southeast corner of the dome level (Figure 6).

Turn the power switch ON to enable the dome rotation system. The power switch will illuminate when turned ON. Turn the power switch to OFF when shutting down after an observing session. The pilot light will extinguish.

Use the dome rotation control switch (yellow box) to rotate the dome. The control switch is spring loaded to OFF (center position). Rotate and hold the control switch handle clockwise to rotate the dome clockwise. Release the switch to stop the dome rotation. Rotate and hold the switch counterclockwise to rotate the dome counterclockwise. Release the switch to stop the rotation.

The control switch is on a long cord, so you can stand behind the telescope and easily get the shutter opening aligned properly. Stow the switch and cord on the hook bracket when shutting down after an observing session.

When the dome is rotating, pay close attention and watch for items that may become jammed. For example, the step-stand can sometimes be trapped between the upper shutter drive shaft and the dome structure. Also, items left on the upper decking (eyepieces, flashlights, books, etc.) can be displaced, fall, jam, damaged, etc.


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Figure 6: Dome Rotating System, Power Switch, and Control Switch

5.5. Telescope Tarps

When not in use, the telescope is parked with the front end resting on the platform above the chart table (Figure 7). There are several fabric coverings on the telescope (Figure 8) that must be removed prior to operation. Remove the large tarp covering the telescope and mount, noting the orientation marking for counter-weight and mirror. Remove the fabric cover – note the orientation and seam with Velcro strap closure and the end tie strings. Remove the pouch-style coverings from the right ascension and declination axes. When the scope is in use, the tarps are typically stowed on the floor in the southwest corner. It may be helpful to use the step-stand during tarp removal in reinstallation. When the telescope is not in-service, the large tarp is left hanging long on the southeast side.

Figure 7:Telescope Park Position


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Figure 8:Telescope Tarps

5.6. Telescope Remote Focuser

The telescope uses a motor driven focuser, a Starizona MicroTouch (Figure 9), to reduce vibration and image jitter when focusing. The focus control hand-pad with battery is mounted on common assembly that is stored in the work room on the first floor. Bring the focuser control assembly to the main observatory floor. Plug the power lead of the battery into the socket on the focuser hand pad, and hang the assembly on the step-stand. The communication between the hand-pad and the focus motor is wireless. When shutting-down, UNPLUG the battery plug from the hand-pad.

If an eyepiece will not come to focus because of insufficient outward focuser travel, the focuser home position may need to be reset. The focuser travel is more than two inches. To reset the home position, run the motor inward and allow the motor to continue to run for a minute or two to ensure over-travel, and reset the home position. It is a good idea to rack the focuser inward and over travel when shutting down for the night.


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Figure 9: Starizona MicroTouch Remote Focuser

5.7. Telrad Finder

The Telrad illuminated reflex sight is used for visual telescope pointing. Internal batteries power the Telrad. To turn-on the Telrad, rotate the rotary switch in the clockwise direction. The switch rotation adjusts the reticle illumination. Remember to turn off the Telrad when the telescope is stored for shutdown.

5.8. Telescope Power and Astrometric Control

Locate the two AC power plugs at the base of the telescope mount and plug them into the service outlet also at the base of the telescope mount (Figure 10). One plug supplies power to the focuser motor and wireless receiver, the other plug supplies power to the regulated power supply for telescope drive control and motors. Plug in both plugs.

When shutting down, UNPLUG both plugs.

Figure 10: AC Power Plugs


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At the base of the mount, sitting atop the drive control box, is a small plastic case containing eyepieces for the telescope and the Astrometric Hand Pad (Figure 11) for controlling telescope motion. Remove the cover of the plastic box.

Locate the control hand-pad (wired) and attach it to step-stand at either of the upper magnetic stow locations.

When shutting down, DO NOT UNPLUG the RJ45 hand-pad connector from the SkyWalker controller on the pier. Simply place the hand-pad in the box and thread the cord through the lid of the storage box.

Figure 11: Astrometric Hand Pad

Remove the dust cover from the drive control power box (Figure 12) and stow it in the eyepiece box.

Locate the rocker switch on the rear of the drive control box and turn it on. A red indicator light on the front should illuminate. This switch is turned-off when shutting down.


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Figure 12: Drive Control Power Box

On the east side of the telescope pier, locate the small toggle switch for the SkyWalker Astrometric Control (Figure 13) and turn it on. A power indicator will illuminate. Other indicators will flash during initialization. After about 30 seconds a low hum will be audible from the RA drive motor. This switch is turned off when shutting down.

Figure 13: SkyWalker Astrometric Control


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6. BASIC TELESCOPE OPERATION

6.1. Dust Covers

Remove the telescope tube end-covers to allow the scope to come to thermal equilibrium. To reduce tube air currents, reinstall the rear cover, which will also help balance of the optical tube assembly. It is best to wait until the mirror cools before you reinstall the rear cover. With the rear cover on, the front cover can be stowed by placing it over the rear cover.

6.2. Eyepiece

Obtain a 1.25-inch eyepiece (25mm focal length is a good start) from the storage box at the base of the telescope. Remove the insert from the focuser and install the eyepiece. Tighten the eyepiece set screw to prevent the eyepiece from slipping out of the holder and stow the insert in the eyepiece storage box.

6.3. Tube Rotation

If the focuser/eyepiece is not easily accessible for viewing, you can rotate the tube in its rings to provide a comfortable eyepiece position.

Caution: Do not attempt to rotate the tube when the telescope is above about 45 degrees or the rotating rings and tube will scrape.

6.4. Slewing Precautions

Before slewing the telescope ensure that the eyepiece is securely tightened so that it doesn't fall out when you change the tube's orientation. Be aware of cords, ladders, and other obstacles. Be careful that the telescope counter weights always remain lower than the tube's centerline. When aiming to the North with the telescope on the East side of the pier, be careful and avoid interference with the RA drive enclosure.

Caution: Do not allow the counterweights to be in a position where gravity could pull them toward the optical tube assembly, thus damaging the telescope as they slam into it.

Caution: Do not allow the eyepiece end of the telescope to be lower than the mirror end. Pay special attention when performing a meridian flip.


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6.5. Aiming the Telescope

At this point the configuration of the telescope and dome allows a user to manually aim the telescope and track an object once it is in the field of view.

1. In the sky, locate the object that you want to view. To make the initial aiming and focusing easy, a bright star or planet should be used as the first object of the night.

2. Rotate the dome as needed to allow the telescope to view the object through the dome slit.

3. Manually position the telescope to view through the dome slit using the handles at the rear of the telescope tube.

4. Note the eyepiece orientation and if it will be inaccessible. Now is a good time to lower the telescope and rotate the tube in its support rings.

5. Refine the telescope aim using the Telrad finder. 6. Place the object in the center of the bulls-eye.

It may be necessary to iterate positioning of the dome and the telescope to acquire the target.

6.6. Acquiring and Viewing the Target

At the eyepiece end of the telescope, re-center the target object in the Telrad finder.

The telescope eyepiece will likely be out of focus. Use the In-Out push-buttons on the MicroTouch hand pad to adjust focus. The two-speed focuser speed increases the longer the button is held depressed.

Use the Astrometric hand pad to center the object in the field of view. The buttons in the diamond pattern move the telescope +/- in RA and +/- in Dec. The orientation between the buttons and motion in the eyepiece will not necessarily correspond, due to tube rotation and image reversal.

The RA motor will hold the target in the field of view.

Using eyepieces of different focal length will change the magnification. There are several holes in a bracket at the top of the step stand used to keep different eyepieces at-hand.


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7. TELESCOPE OPERATION USING THE NGC-MAX OBJECT CATALOG

NGC-MAX is a microcomputer with a database of celestial objects and their coordinates. It is used to aim the telescope at these objects using position encoders on the telescope RA and Dec axes. For the system to function, the computer must be initialized (star-aligned) by aiming the telescope at one of several reference stars and synchronizing the telescope axis encoders to these celestial coordinates. Subsequently, objects can then be selected and acquired in the telescope by using the NGC-MAX display.

On the north-side of telescope pier between the floor and the RA axis, locate the fabric dust cover on the NGC-MAX Control Box (Figure 14). Remove the NGC-MAX dust cover and stow it in the eyepiece box.

Figure 14:NGC-MAX Control Box

7.1. Align Star Mode

1. Orient the mount so that the telescope is on the West side and the counterweights are on the East side of the pier.

2. Orient the shutter opening so that an appropriate alignment star is visible to the east. There are approximately 26 default alignment stars in the NGC-MAX database. There is a chart of these stars in the green cover storage box.

3. Turn on the NGC-MAX and wait 5 seconds. 4. Adjust display brightness as desired by pressing the button next to the

on/off switch. 5. The display should read: MODE ALIGN STAR. Press Enter. 6. The display should read: ALIGN ACHERNAR. You need not use the star

Achernar. Choose your own star by pointing the telescope at an easily located bright star east of the meridian. You MUST use one of the stars listed in the menu. You can scroll through the menu using the up and down buttons.

7. Locate the star using the Telrad and center the star in telescope eyepiece. Use higher power eyepieces for more precision if desired. Press Enter.


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8. The NGC-MAX should indicate a ‘Warp’ of 0. Calibration of the NGC-MAX is now complete.

9. Note: If the ‘Warp’ is not zero, check that the telescope SETUP is set to ‘SCOPE GP’, polar aligned German mount.

7.2. Catalog and Guide Modes

1. Go to Catalog Mode using the up or down keys. Press Enter. 2. Scroll through the catalog and locate the desired object using the scroll

keys. Press Enter. 3. Press Mode. 4. Scroll to Guide Mode. Press Enter. 5. Move the telescope (also see Slewing below) until the display shows all

zeros. Ignore the arrow on the display and simply move the telescope in the direction necessary to reduce the numbers to zero.

6. You should be on the target object. The display should show + between the zeros, not an arrow.

7. If you find that the object is not very close to the zero position on the NGC-MAX, you can align the NGC-MAX on the current object. This will improve accuracy in this portion of the sky, but may also degrade accuracy in the opposite direction.

8. If you are using the Planets catalog, you will need to input the current date in Universal Time (UT) to obtain correct planet locations. Press Enter. Press Enter again. The format is MM-DD-YYYY. Use Up, Down and Enter, to set the date.

8. SLEWING TO AN OBJECT WITH THE ASTROMETRIC HAND PAD

The Slew button (bottom middle) on the Astrometric hand pad increases the speed of telescope motion. Slew speed is useful for aiming the telescope using the NGC-MAX display. The light above the Slew button is illuminated when the higher speed is engaged. When Slew is off, the speed returns to ‘View speed’. View speed is used to center objects in the field of view when at the telescope eye-piece.

1. Press Slew on the Astrometric Hand Pad (Figure 11). The light above the slew button will illuminate.

2. With the NGC-MAX in Guide Mode and using the Direction Buttons on the Astrometric hand pad, position the telescope in RA and Dec using the axis drive motors until NGC-MAX display shows all zeros.

3. Ignore the arrow on the NGC-MAX display and simply move the telescope in the direction necessary to reduce the numbers to zero + zero.

4. You should be on the target object when the NGC-MAX display shows + between the zeros, not an arrow.


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5. Press Slew again to return to View speed. The light above the Slew button should extinguish.

6. Center the object in the eye-piece using View speed.

8.1. Notes on Astrometric Hand Pad Operation

Pay special attention when performing a meridian flip using the hand pad. To avoid stressing the mirror retainer, always keep the mirror end of the telescope below, or level with, the eyepiece end. Always keep the counterweights below, or level with, the telescope tube.

To change the slew/view speeds, press and hold the View/Vel key (bottom left side of keypad) and use the up-down direction buttons to make the changes. The LED indicator bar (lower left side) shows the various velocity options. The more LEDs lit, the faster the telescope movement.

To change the constant telescope mount tracking rate (keeping objects in the field of view as the Earth turns), press and hold the “Track Rate” button (middle left side of keypad), and then use the up-down buttons to move through the five preset tracking rates: 1) Sidereal (normal), 2) Lunar, 3) Solar, 4) Custom, and 5) Drift (no LEDs lit). Usually this will not need to be changed from Sidereal, but sometimes in the dark things happen, so if the telescope isn’t tracking properly, check the Track Rate.

Illumination - Press the Dim/Map button (upper right side of keypad) to turn on the hand pad illumination. Use the up key to brighten and the down key to dim the illumination. The range of brightness is from 0 (i.e. off) to 8 (i.e. bright).

9. TELESCOPE OPERATION USING THE LAPTOP COMPUTER

The Isengard telescope can be controlled with a laptop computer using Maestro and TheSky software.

The laptop is stored in the first-floor work room. The Isengard laptop is stored in a black fabric case labeled ‘Isengard’.

1. The laptop computer connects to the telescope with a Keyspan USB to Serial port adapter, which in turn is connected to a RS-232 DB-9 (serial) connector. Simply plug the USB connector at the end of the cable into a USB port on the laptop. The Keyspan adapter and connecting cable are coiled on the left side of the chart table.

2. Before booting the computer, turn on the Isengard's tracking system (Skywalker Astrometric). There are two switches for that purpose; one on the floor next to the mount and one on the mount itself. (See Section 5.8 Telescope Power and Astrometric Control)


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3. After the computer boots and the Windows desktop appears on the screen, start the Maestro software by clicking on the Maestro icon.

4. Watch the bottom of the Maestro screen and wait for the sky object database to load.

5. Verify that the log says initialization complete in the bottom status area. 6. Start TheSky software by clicking on the TheSky icon. TheSky provides a

planetarium image of the night sky on the screen. 7. There are several ways to align and synchronize the telescope with the

computer. First decide which star or other object to use for alignment. Use one of the following steps: a. Choose from TheSky top menu, Edit/Find/Stellar/Common Names/some

star. When the dialog box appears, click on Center & Frame. b. Simply point and click on a star or other object on the screen. Manually

point the Isengard scope at the star chosen for alignment. c. If you already have the telescope aimed at an object from previously using

NGC-MAX or purely from manual aiming, find that object on TheSky’s screen, place the cursor on it and click.

8. A red bull’s-eye will appear along with a description of the object. Confirm that the object information displayed is the same as that of the object at which you are aimed.

9. From TheSky top menu, choose Telescope/Link/Establish. 10. In the dialog box accompanying stellar object, click on the Sync button. A

white bull’s-eye should appear superimposed on the red bull’s-eye. 11. Confirm synchronization by going back to Maestro software. In the bottom

status bar, the log should state Calibration Completed. 12. Once the telescope and the laptop are synchronized, the white bull’s-eye

indicates where the telescope is aimed, and the red bull’s-eye is the selected object.

13. To slew to a new object, locate the object on TheSky’s planetarium screen and click on it to place the red bull’s-eye. The white bull’s-eye will remain where the telescope is presently aimed, on the current target.

14. The sub-window will display info on the selected new object. Verify that this is the desired target.

15. In the sub-window select the ‘slew telescope’ tab to slew to the new object. 16. You will be asked to confirm the action before the telescope will begin to

move. Insure that personnel and equipment are positioned away from the telescope to avoid collision as the telescope moves.

NOTE: A cancel/abort window will appear on the screen. It is recommended practice to hover the mouse cursor over this selection while you monitor the telescope’s motion, so you can quickly stop the telescope if necessary.

17. Under computer control the telescope will move to the new target. The telescope will automatically perform a meridian flip if needed. On TheSky’s


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screen, the white bull’s-eye will move with the telescope’s motion, until it is coincident with the red target object bull’s-eye.

18. At the eyepiece, use the Astrometric Hand pad to positon the object in the field of view, if needed.

There are too many features of TheSky to cover in this document. As you gain familiarity with it you will find many ways to access objects for viewing, information and enjoyment.

10. COMPUTER SHUTDOWN

It is important that you choose Telescope/Link/Terminate from TheSky top menu before closing TheSky software.

First exit TheSky, and then exit Maestro.

We typically ‘hibernate’ the laptop when we are done. If you do not see the Hibernate option when shutting down the laptop, depress the shift key and the left-most option should change from Stand-by to Hibernate.

Do not use ‘suspend’ or ‘stand-by’, as this will slowly drain the laptop battery and may result in battery failure (the battery may later refuse to charge).


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VERSION HISTORY

Version Effective Date Description of Change

1 5/17/17 Initial Document 2 11/26/17 Added dome rotation system procedures.


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Attachment 1: ISENGARD STARTUP/SHUTDOWN CHECKLIST

OPENING TASK CLOSING ▼ ▲ On Stairway and lobby lights Off On Dome lighting / desk lighting Off

Check Upper shutter is opened before lower shutter NA

NA Upper shutter overlaps lower shutter when closed Check

On Dome motor power switch Off

NA Dome is rotated so that the shutter is parked to the South Check

Remove Tarps on the telescope Install Remove Tarps on the RA + Dec axes Install To 2nd Fl. Remote focuser stored in first floor work room To 1st Fl. Plug-in Remote focuser battery power lead Unplug Plug-in Telescope and focuser AC power plugs Unplug

Remove Dust covers for power supply and NGC MAX Install On Regulated power supply Off

In use Astrometric hand controller Stow In use Eyepieces and focuser dust plug Stow

On Telrad finder switch Off On Astrometric Drive switch Off On NCG-Max switch Off NA Telescope positioned at the chart table Park

Remove Telescope end-cap dust covers - Install/remove if used Isengard laptop from/to the Computer Room if used

NA Hibernate the laptop if laptop NA Exit Maestro if laptop NA Telescope/Link/Terminate then exit TheSky if laptop ▼ ▲

OPENING TASK CLOSING

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