Inserting a TPoint
object into TheSky

Related Links

Background

In order to use TPoint for Windows with TheSky a TPoint model must be "embedded" as an object within TheSky. This type of Object Linking and Embedding is analogous to inserting a Microsoft Excel spread sheet say into Microsoft Word. These are two separate applications that can perform individual tasks but they can also share information between each application.

Inserting a TPoint Object into TheSky

To Insert TPoint  as an object into TheSky use Edit | Insert New Object in TheSky. You will be presented with a list of objects registered with the system. Use the option Create New as opposed to Create from file.

Edit
Insert New Object

NOTE: If you already have inserted a TPoint object it will have to be DELETED before a new one can be inserted.

Inserting a New Object (TPoint model)

Choose TPoint from the list

NOTE: The option to "Create from File" allows you to use a TPoint model that is not currently inserted in TheSky. It requires an existing working TPoint model that was previously created. Sometimes this can save you from loosing a TPoint when you accidentally deleted it in TheSky.

Wait! I don't see TPoint listed? < -- How to Register TPoint with the system!

If you want TPoint to take up as little real estate as possible choose the option "Display As Icon" as checked and highlighted above. When this is done TPoint has a very small foot print and only takes up a small part of the main display. See below.

TPoint shown as an Icon

Smaller foot print less obstructive

As opposed to full size. NOTE: The following box can be resized!

TPoint can cover a lot of the sky

The object can be resized smaller!

Either forms will work. The one advantage the larger size has is it will show a scatter diagram as you are mapping points indicating your current RMS pointing.

Scatter diagram mode showing mapped points

Much larger than Icon

NOTE: By right mouse clicking on the TPoint object in either form you can toggle between the two options Icon or not an Icon. This can be very handy at times

Deleting an existing TPoint object

You will know if a TPoint model is already inserted. First you will see the Icon or scatter diagram in the main display and second you cannot insert a new TPoint model until the existing one has been removed. The following shows that a TPoint model is already available.

Can't insert a TPoint model

when one already exists

To DELETE the existing model just left mouse click on the Icon or scatter diagram to get focus then press the DELETE key. You will be prompted for the deletion of the inserted object. See below.

Delete current model

Choose Yes to delete the existing object

Mapping stars when TPoint is inserted

When a TPoint model has been embedded within TheSky you are ready to start mapping stars. The telescope must first be homed and also Synced properly before you can start the mapping run.

 

The button to slew the telescope is the green icon (telescope icon) located on the Object Information dialog.

Slew Icon

Green telescope

The button used to map a star after centering after the slew is the red cross hair icon.

Map Icon

Red cross hair

Below shows the location of BOTH the slew to and mapping icon located on the Telescope tab on the Object Information dialog.

Telescope Tab on the Object Information dialog

Slew and Map icons are highlighted

Sample mapping run <---- Start in a small area of the sky at first.

Accurately center the first star then "Sync" it
Sync button is highlighted above

Once the first star has been centered accurately and "Synced" you can also MAP it as your first point. Press the MAP button after the initial one time "Sync".

Sample mapping run in Lyra!
Stars in close proximity first to minimize pointing issues

Image Link And Synch

A better method for the initial Synch is to use Image Link and Synch assuming you are going to map with the CCD camera in place (auto-mapping). Then start mapping from there. Image Link and Synch is simple to do, it is faster and it does not require any re-centering of the star and it works even if there aren't bright stars in the field (i.e. the star was missed!). Image Link is very smart. And by knowing your scale you can search very large fields for a match. Even larger than your actual field of view. With minimal effort you can Home the Paramount ME, slew to the first star near the home position and simply have Image Link find the center of the image.

 

And a resounding yes to can I just slew Image Link and map slew Image Link and map. That is exactly how the automated mapping procedure works. It is extremely efficient since you do not have to move the scope to re-center the objects Image Link does the work for you.

 

Hint: You may need to "SUSPEND" the telescope link when finding matches way outside of the field of view. If not the display will jump back to the cross hair position which at this point is not accurate and may take you off the true telescope's position.

 

So after the telescope has been initially synced you do not sync again! Note that you cannot go back and add more points to a TPoint model on a different night!  See the TPoint manual for details on using a "Short Mapping Run" to fix pointing instead of trying to add points on successive nights which only pollutes the TPoint model.

Sync only once then use map!
Use the map button highlighted

To make the Object Information dialog smaller press the Down arrow (Minimize button) found on the lower right. When minimized you can use the Green Slew To button and then the Red Map button for quick easy slewing and mapping. This is also less prone to inadvertently Syncing the telescope again because the telescope tab is hidden.

Minimize Object Information Dialog
This takes less room and it
is less prone to making Syncing errors!

Do Not Map this Star!
Assume the worst!

If you get the error message warning (see above) indicating that the star is not being correctly mapped and it appears to be in error, DO NOT map the point by clicking “No”. Slew to the same star again and make certain that you are mapping the proper star first. This is important. 
 

If you continually see the mapping error when mapping the CORRECTLY verified stars (that is you are certain they are the correct ones) you have a major problem with the alignment elsewhere, i.e. very poorly mounted OTA or mount is off extremely far off the pole. In this case attempts should be made to refine the alignment of the mountings first, i.e. the Drift Method to refine polar alignment, before trying to map again. You cannot start shimming the mounting of the OTA until TPoint tells you exactly how much. That is a catch 22. Keep in mind that only 1 to 2 thousandths of an inch miss-alignment in mounting will introduce pointing errors on the arc minute level. Again, TPoint to the rescue!

 

If you inadvertently click on something other than the star you intend to map (cursor position, galaxy (did you turn off galaxies, nebulae, clusters, etc. wrong star, or other object) the objects name you clicked on or “Cursor Position” is displayed in the Object Information dialog. That is this is not the star you intended to map. This too can happen easily so always double check the star name in the Object Information dialog first then press map when you are sure. For first time Tpointer’s you should make sure that you have the option to Confirm Mapping  found under the Telescope-Setup options. This way you must always confirm the stars you are mapping.

 

Editing the TPoint Object - Model

Once TPoint has been inserted into TheSky you can start adding mapping data to the model. That is slew, center the object, and map the point. After 6 to 12 stars are mapped you will want to Edit the model and add some additional terms to improve the pointing.

 

Note you will know if TPoint has been properly inserted into TheSky by the following. The new Icon or scatter diagram will show on the main display and under Edit in TheSky there is a new entry for the TPoint object. That is Edit | TPoint Model Object. This allows you to actually OPEN the TPoint model editing.

 

An easier way to actually open the model is to simply double left mouse click on the TPoint icon or scatter diagram. This too will open the TPoint model for editing. Either way.

TPoint open and ready to be edited

Spread sheet showing mapped points

Exiting TPoint and returning to TheSky

WARNING! When you are done evaluating, marking any errors, adding additional terms, checking polar alignment, etc. use File | Exit and Return to TheSky or use the Windows Close [X]. This will return you to TheSky and close TPoint. Make sure you don't inadvertently leave TPoint open! You must close or exit it in order to continue working normally with TheSky!

File | Exit & Return to TheSky
Get out of TPoint by closing or File | Exiting

Registering TPoint with the system

Before a TPoint model can be inserted into TheSky (as an object) it must first be registered with the system. Easy enough. This just means that you must have launched TPoint at least once on its' own first. Use Start | and find TPoint in your program list under the program group named TPoint and then launch the TPoint application. This is all that is required to register the program. Once loaded you can just EXIT the program. That is File | Exit. Now a TPoint object can be inserted into TheSky but not before.

 

Please refer to the TPoint manual for additional information.