en:ost:telescope:setup

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en:ost:telescope:setup [2021/05/29 15:48] – rhainichen:ost:telescope:setup [2024/07/11 07:45] (current) – [Refining the alignment] rhainich
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-FIXME <fs xx-large><fc #ff0000>This page is currently under revision.</fc></fs> 
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 ====== Telescope setup and maintenance ====== ====== Telescope setup and maintenance ======
    
-===== Setup of the mount =====+===== Setup of the GM4000 HPS II mount =====
  
-==== Using the mount directly ====+==== Using the mount directly via the handheld terminal ====
 === Alignment === === Alignment ===
  
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     * to improve the accuracy all stars should be spread across the whole sky     * to improve the accuracy all stars should be spread across the whole sky
  
-There are further methods to change/improve the alignment that are documented in the manual of the GM 4000 QCI, which can be found in room 2.009.+There are further methods to change/improve the alignment that are documented in the manual of the GM 4000 HPS II, which can be found in room 2.009.
  
  
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 <WRAP twothirds column> <WRAP twothirds column>
  
-The advantage of setting up the mount via the OMS is that a much more precise pointing model can be created, since not only a few stars are used, but up to 100 star fields distributed over the whole sky can be utilized. The exact position of these star fields is determined automatically with the help of the so-called [[https://en.wikipedia.org/wiki/Astrometric_solving | Plate Solving]].  +The advantage of setting up the mount via the OMS is that a much more precise pointing model can be created, since not only a few stars are used, but up to 100 star fields distributed over the whole sky can be utilized. The exact position of these star fields is determined automatically with the help of the so-called [[https://en.wikipedia.org/wiki/Astrometric_solving | Plate Solving]]. We use the software //ModelCreator//.
- +
-We use the software //ModelCreator//.+
  
-The most important settings in the **Equipment** tab such as **Camera**, **Mount**, **Solver** and **Dome** should already be preset. These settings are stored as profiles. The predefined profiles can be selected from the **Profile** drop-down menu. By clicking on **Profiles** the profiles can be edited and also new ones can be created. By clicking on the ''Connect'' buttons at **Camera**, **Mount** and **Dome** the corresponding devices can be connected to the //ModelCreator//. In the case of the camera, it must be ensured that the camera is connected beforehand to //MaxIm DL// because //ModelCreator// fetches the data from there.+The most important settings in the **Equipment** tab such as **Camera**, **Mount**, **Solver**, and **Dome** should already be preset. These settings are stored as profiles. The predefined profiles can be selected from the **Profile** drop-down menu. By clicking on **Profiles** the profiles can be edited and also new ones can be created. By clicking on the ''Connect'' buttons at **Camera**, **Mount**, and **Dome** the corresponding devices can be connected to the //ModelCreator//. In the case of the camera, it must be ensured that the camera is connected beforehand to //MaxIm DL// because //ModelCreator// fetches the data from there.
  
-Next you should set the points where //ModelCreator// will create images of the sky. You should set a minimum height above the horizon (''Min Alt''), because points too close to the horizon do not make sense due to the long way the light travels through the atmosphere. It has been proven that at least a minimum altitude of 15° is necessary. Furthermore, it has turned out to be useful to activate the option ''Equal az spacing'' in order to achieve an optimized distribution of the points. If you also activate the option ''Show number'' the order in which the points are processed is also displayed. Afterwards you can click on **Generate** to generate the points. After that you can click on **Sort-EW** to sort the points from east to west. This significantly reduces the overall slewing time required by the mount. For our final pointing model we usually use up to 100 points. For this we usually set ''Points per row'' and ''Rows'' to 10 each. Additionally 3 base points can be selected. Click on the corresponding points with the mouse. +Next you should set the points where //ModelCreator// will create images of the sky. You should set a minimum height above the horizon (''Min Alt''), because points too close to the horizon do not make sense due to the long way the light travels through the atmosphere. It has been proven that at least a minimum altitude of 15° is necessary. Furthermore, it has turned out to be useful to activate the option ''Equal az spacing'' in order to achieve an optimized distribution of the points. If you also activate the option ''Show number'', the order in which the points are processed will also displayed. Afterwards you can click on **Generate** to generate the points. After that you can click on **Sort-EW** to sort the points from east to west. This significantly reduces the overall slewing time required by the mount. For our final pointing model we usually use up to 100 points. For this we usually set ''Points per row'' and ''Rows'' to 10 each. Additionally 3 base points can be selected. Click on the corresponding points with the mouse. 
  
 It has proven useful to increase the exposure time for points close to the horizon, because there the air mass increases significantly. Otherwise not enough objects can be identified. For points in the Milky Way, on the other hand, it can happen that no solution can be achieved by plate solving, because there seem to be too many stars in this area. In this case, it might be helpful to reduce the exposure time. The exposure time can be adjusted via the **Control** tab. Here you should also set a ''Slew settle time'' of 3s and the focal length of the telescope (''Focal Length'').  It has proven useful to increase the exposure time for points close to the horizon, because there the air mass increases significantly. Otherwise not enough objects can be identified. For points in the Milky Way, on the other hand, it can happen that no solution can be achieved by plate solving, because there seem to be too many stars in this area. In this case, it might be helpful to reduce the exposure time. The exposure time can be adjusted via the **Control** tab. Here you should also set a ''Slew settle time'' of 3s and the focal length of the telescope (''Focal Length''). 
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 </WRAP> </WRAP>
 <WRAP third column> <WRAP third column>
-[{{ :ost:software:platesolve_5.png | Recorded star field - Red crosses: detected stars, Turquoise crosses: catalog stars, Yellow circles: identified stars}}]+[{{ :ost:software:platesolve_5.png | Image of the star field - Red crosses: detected stars, Turquoise crosses: catalog stars, Yellow circles: identified stars}}]
 </WRAP> </WRAP>
 </WRAP> </WRAP>
  
-//PlateSolve// identifies the stars in the respective star field and compares their position with star catalogs. Starting from the coordinates provided by the telescope, a spiral outward search is performed. In the example in the center below, the first step of the iteration was already successful and the star field was successfully identified. If the pointing model is not yet as good as in this example, which is usually the case when a completely new pointing model is created, it may take several iterations until the star field is identified. If after 99 iterations the star field has not been found, the iteration is aborted and //ModelCreator// moves on to the next pointing without any changes.+//PlateSolve// identifies the stars in the respective star field and compares their position with star catalogs. Starting from the coordinates provided by the telescope, a spiral outward search is performed. In the example above (the screenshot in the middle), the first step of the iteration was already successful and the star field was successfully identified. If the pointing model is not yet as good as in this example, which is usually the case when a completely new pointing model is created, it may take several iterations until the star field is identified. If after 99 iterations the star field has not been found, the iteration is aborted and //ModelCreator// moves on to the next pointing.
  
 </WRAP> </WRAP>
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 The Periodic Error Correction (PEC) can help to improve the tracking accuracy of the mounting by accounting for periodic errors of the worm gear. This error usually has a period of approx. 3 min 20 sec (3.3 minutes), while the PEC can correct for shorter periods, too. The error of the worm gear is usually irrelevant as long as the observations are only carried out with an eyepiece -- in case longer observations are taken with CCDs, the corrections of this error are getting important. The Periodic Error Correction (PEC) can help to improve the tracking accuracy of the mounting by accounting for periodic errors of the worm gear. This error usually has a period of approx. 3 min 20 sec (3.3 minutes), while the PEC can correct for shorter periods, too. The error of the worm gear is usually irrelevant as long as the observations are only carried out with an eyepiece -- in case longer observations are taken with CCDs, the corrections of this error are getting important.
  
-The PEC has to be calibrated before it can operate properly. For this purpose, the mount needs detailed information on the deviations from the ideal tracking behavior. One possibility to achieve this is by centering a bright star in an eyepiece and following its motions with the hand terminal (the N - S - E - W buttons) for a while. A more sophisticated option is based on the [[en:ost:ccds:ccdops#Guiding|autoguide functionality]] of our CCD cameras, as the precision is higher this way. Start the PEC calibration on the hand terminal with:+The PEC has to be calibrated before it can operate properly. For this purpose, the mount needs detailed information on the deviations from the ideal tracking behavior. One possibility to achieve this is by centering a bright star in an eyepiece and following its motions with the hand terminal (the N - S - E - W buttons) for a while. A more sophisticated option is based on the [[en:ost:ccds:ccdops#Guiding|autoguide functionality]] of our CCD cameras, as the precision is higher this way. It is recommended to train the PEC directly via the handheld terminal. The training algorithm of the PEC is started by means of:
  
 <code>Drive -> A-PEC control -> A-PEC Training</code> <code>Drive -> A-PEC control -> A-PEC Training</code>
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  **ATTENTION:** ONLY VERY MARGINAL CORRECTIONS NEED TO BE APPLIED TO THE SCREWS!  **ATTENTION:** ONLY VERY MARGINAL CORRECTIONS NEED TO BE APPLIED TO THE SCREWS!
  
-==== Pflege der Schmidtplatte ====+==== Maintaining the Schmidt plate ====
  
-Nicht anfassen und immer schön nach der Beobachtung den Deckel auf das Teleskop machen damit sich nicht unnötig viel Staub auf der Schmidtplatte sammelt! Besonders im Herbst und Winter bietet es sich an die Taukappe zu verwenden, um unnötige Kondensation vorzubeugen.+Do not touch and always put the lid on the telescope after observations to avoid unnecessary dust accumulation on the Schmidt plate! Especially in autumn and winter it is advisable to use the dew cap to prevent unnecessary condensation.
  
-=== Reinigung ===+=== Cleaning ===
  
 <WRAP group> <WRAP group>
 <WRAP half column> <WRAP half column>
-Von Zeit zu Zeit müssen die Schmidtplatten unsere Schmidt-Cassegrain-Teleskope gereinigt werden. Dies ist ein diffiziler Prozess, da man hierbei um jeden Preis vermindern muss, dass die Schidtplatte z.B. durch Kratzer beschädigt wird. +From time to time the Schmidt plates of our Schmidt-Cassegrain telescopes have to be cleaned. This is a difficult process, because we have to avoid at all costs that the Schmidt plate is damaged e.g. by scratches. 
  
-**Die folgenden Materialien werden benötigt:**+**The following materials are required:**
 <WRAP half column> <WRAP half column>
-   * Destilliertes Wasser +   * Distilled water 
-   * Alkohol - Isopropanol +   * Alcohol - isopropanol 
-   * Kosmetiktücher oder Zellstofftaschentücher, die man in die einzelnen Lagen teilen kann +   * Cosmetic wipes or soft cellulose handkerchiefs that can be separated into the individual layers. 
-     * **Sehr wichtig:** Die Tücher dürfen keine Lotionen, Geruchsstoffe oder Sonstiges in diese Richtung enthalten  +     * **Very important:** The tissues must not contain lotions, odorants, or anything else along these lines  
-   * Wattebäusche +   * Cotton balls 
-   * Kamelhaarpinzel  +   * Camel hair brush  
-   * Mikrofasertuch  +   * Microfiber cloth  
-   * Reines Spülmittel ohne weitere Zusätze wie z.B. Pflegestoffe für die Hände +   * Pure dishwashing detergent with no other additives such as hand conditioners 
-   * Optional: Kleiner Blasebalg oder Druckluftflasche ohne Treibmittel+   * Optional: A small bellows or a compressed air bottle without propellant
 </WRAP> </WRAP>
 <WRAP half column> <WRAP half column>
-[{{ ost:telescope:cleaning_stuff.jpg?200 | Reiningungsmittel}}]+[{{ ost:telescope:cleaning_stuff.jpg?200 | Cleaning products}}]
 </WRAP> </WRAP>
  
-**Vorgehensweise:** +**Procedure:** 
-  - Als erstes sollte man das Teleskop in eine Position bringen, in der es möglichst ein bisschen in Richtung Boden schaut. Auf diese Weise kann verhindert werden, dass Reinigungsflüssigkeit in das Teleskop läuft. +  - The first thing to do is to put the telescope in a position where it looks a little bit towards the ground (if possible). In this way, cleaning fluid can be prevented from running into the telescope. 
-  - Loser Staub kann mittels des Blasebalg oder der Druckluftflasche entfernt werden. Hierbei muss darauf geachtet werden, dass in einem möglichst flachen Winkel auf die Schmidtplatte geblasen wird, um die Verschmutzungen von der Schmidtplatte zu blasen und diese nicht noch weiter auf die Schmidtplatte zu drücken. Mit einer Druckluftflasche sollte man zuerst probe Sprühstöße machen, sodass man ein Gefühl dafür bekommt, wie viel Luft herauskommt und um sicher zugehen, dass sich durch den Einsatz nicht doch irgendwelche zusätzlichen Ablagerungen auf der Schmidtplatte bilden können.  +  - Loose dust can be removed using the bellows or the compressed air bottle. Care must be taken to blow at as shallow an angle as possible onto the Schmidt plate to blow the dirt off the Schmidt plate and not push it further onto the Schmidt plate. With a compressed air bottle, do test sprays first so you can get a feel for how much air is coming out. In addition, this is a good way to make sure that the use of the compressed air bottle does not cause any additional deposits to form on the Schmidt plate.  
-  - Als nächstes können weitere Verunreinigungen mittels des Kamelhaarpinzels entfernt werden. +  - Next, further impurities can be removed using the camel hair brush. 
-  - Als Reinigungsflüssigkeit bietet sich eine Mischung aus destillierten Wasser und Isopropanol im Verhältnis 50:50 oder 50:60 an. Des Weiteren kann für stark verschmutzte Oberflächen auch noch ein wenig Spülmittel hinzugehen werden. Auf 500ml Reinigungsflüssigkeit sollte nicht mehr als 1 Tropfen hinzugeben werden, da sonst Rückstände auf der Schmidtplatte verbleiben können.  +  - A mixture of distilled water and isopropanol in a ratio of 50:50 or 50:60 is suitable as a cleaning fluid. Furthermore, for heavily soiled surfaces, a little washing-up liquid can also be added. No more than 1 drop should be added per 500 ml of cleaning liquid, otherwise residues may remain on the Schmidt plate.  
-  - Ist die Schmidtplatte stark mit klebrigen Pollen belegt, biete es sich an, den Belag vorsichtig einzuweichen. Hierfür mit dem Pinsel vorsichtig ein wenig Reinigungsflüsigkeit auftragen. Hierbei möglichst in Quadraten arbeiten. +  - If the Schmidt plate is heavily coated with sticky pollen, it is advisable to soak the deposit carefully. To do this, carefully apply a little cleaning liquid with a brush. Work in squares if possible. 
-  - Mit befeuchteten Wattebäuschen zuerst die starken Verschmutzungen entfernen. Hierfür immer in geraden Linien am besten von innen nach außen streichen und den Wattebausch dabei rotieren, damit man mit den am Wattebausch haftenden Verunreinigungen nicht über die Oberfläche reibt. Nur mit ganz wenig Druck arbeiten und niemals in Kreisen reiben. +  - Then remove the heavy soiling with moistened cotton balls. Always work in straight lines, preferably from the inside to the outside, rotating the cotton ball so that the dirt adhering to the cotton ball does not rub over the surface. Use very little pressure and never rub in circles. 
-  - Anschließend die verbliebenen Verunreinigungen mit befeuchteten Kosmetiktüchern entfernen. Hierfür wieder in geraden Linien von innen nach außen mit leichtem Druck streichen und dabei vermeiden, dass der aufgenommene Dreck an der Schmidtplatte reibt.  +  - Then remove the remaining impurities with moistened cosmetic tissues. For this purpose, again stroke in straight lines from the inside to the outside with light pressure, avoiding that the absorbed dirt rubs against the Schmidt plate.  
-  - Die Reinigungsflüssigkeit sollte abtrocknen ohne Rückstände zu hinterlassen. Ist dies nicht der Fall, sollte der Reinigungsvorgang noch einmal mit einer neu angesetzten Reinigungslösung ohne Spülmittel wiederholt werden. +  - The cleaning liquid should dry off without leaving any residue. If this is not the case, the cleaning process should be repeated again with a newly prepared cleaning solution without detergent. 
 </WRAP> </WRAP>
 <WRAP half column> <WRAP half column>
-[{{ ost:telescope:schmidt_plate_dirty_rot.jpg | Schmidtplatte mit Staub und Pollen}}]+[{{ ost:telescope:schmidt_plate_dirty_rot.jpg | Schmidt plate with dust and pollen}}]
 \\ \\
-/* +[{{ ost:telescope:schmidt_plate_clean.jpg?500 | Cleaned Schmidt plate}}]
-[{{ ost:telescope:cleaning_stuff.jpg?200 | Reiningungsmittel}}] +
-*/ +
-[{{ ost:telescope:schmidt_plate_clean.jpg?500 | Gereinigte Schmidtplatte }}]+
 </WRAP> </WRAP>
 </WRAP> </WRAP>
  
-===== Corrected Dall-Kirkham-Teleskop - CDK20 =====+===== Corrected Dall-Kirkham telescope - CDK20 =====
  
-==== Kollimation ====+==== Collimation ====
  
-  * kommt noch ... +  * Will follow soon ... 
  
-==== Reinigung der Spiegel ====+==== Cleaning the mirror ====
  
-Für die Reinigung des Spiegels müssen im Prinzip die gleichen Schritte durchgeführt werden wie für die Reinigung der Schmidtplatten bei den Schmidt-Cassegrain-Teleskopen mit folgenden Ausnahmen:+To clean the mirror, basically the same steps must be followed as for cleaning the Schmidt plates on Schmidt-Cassegrain telescopes with the following exceptions:
  
-**Zusätzlich benötigte Materialien:** +**Additional materials needed:** 
-  * Papierhandtücher+  * Paper towels
  
-**Änderungen bei der Vorgehensweise:** +**Changes in procedure:** 
-  * Bei Reinigung des Hauptspiegels: +  * When cleaning the primary mirror: 
-    - Zusätzlich sollte man einige Papierhandtücher in die Kohlefaserhülle um den Spiegel legen, sodass überflüssige Reinigungsflüssigkeit von diesen aufgenommen wird und nicht hinter den Spielgel läuft und dort z.B. in Kontakt mit der dort verbauten Elektronik kommt. Die Papierhandtücher dürfen nicht in Kontakt mit dem Spiegel kommen.  +    - In addition, some paper towels should be placed in the carbon fiber sleeve around the mirror so that excess cleaning fluid is absorbed by them and does not run behind the mirror and come in contact with the electronics installed there. The paper towels must not come into contact with the mirror.  
-  * Bei Reinigung des Sekundärspiegels: +  * When cleaning the secondary mirror: 
-    - Das Teleskop sollte in diesem Fall ein paar Grad über den Horizont schauen.+    - The telescope should look a few degrees above the horizon in this case.
  
 ===== Problems and their solution ===== ===== Problems and their solution =====
  • en/ost/telescope/setup.1622303316.txt.gz
  • Last modified: 2021/05/29 15:48
  • by rhainich