Saving N-Point Alignment Data

Saving N-Point Alignment Data

Procedure for saving data:

  • Perform N-Point alignment as usual.
  • Open the “Alignment Point List Editor” window by clicking on [Point List] button.
  • Click on the preset drop down list and select a preset.
  • Click on the preset name to rename it
  • Click the [Save] button to save the alignment data. (There is also an option “Save Alignment Points to Preset on PARK”.)

Procedure for loading data:

  • Click on [Point List] button
  • Select the preset you want to load
  • Click the [Load] button - new alignment is applied immediately. (There is also an option “Load Alignment Points from Preset on UNPARK”.)

Procedure for saving on APPEND:

As of version 1.22g, you can now set an option to save (as you go) your alignment points. This helps in the case of computer crashes as you will not lose your alignment points that have been have been created in the current session.. Just click the option on.

See the “Other Comments” below concerning using presets as backup of alignment data.

Automatic Saving and Loading of Alignment data

In the “Alignment Point List Editor” window there are 3 check box items. You can select any of the options.

You can choose to automatically save the data when you park the mount. This is an excellent option for those of us who forget that the alignment data will not be saved unless you do save it manually or use this option. You should know, however, that if you use the automatic save option, the alignment data will be saved in the currently selected preset and it will replace the previous contents. See the “Other Comments” below about keeping copies of your “good” alignment data as a backup..

You can choose to automatically load the alignment data from a previous session when you unpark the mount. In most cases, this is probably what you want. Starting a new evening session, automatically loading up your previously stored alignment points means your 'scope will probably be able to centre on objects with the same accuracy as the previous session immediately with no further alignment required.

You can chose to automatically save each alignment point as it is appended in the current session rather than waiting for the park option or the manual save event.

However, you may wish to “goto”several objects and tweak the positioning followed by a “synch”. If you have the “Synch behaviour” set to “Append on Sync” the new synchronization will be added to the star list. If you then determine that each of the synchronizations for the current session need significant adjustment (you decide what's significant) from the GOTO position, you may want to delete alignments that have been stored from previous sessions. Simply click on the star alignment data line and click the [Delete Point] button.

Other comments about Saving and Loading of Alignment data

It's always a good idea to use at least two presets particularly if you use the save on park option. This is probably the most common application of using the star list presets. Use one as a backup of a known 'good' set. The other would be the current working set. Using duplicates is also quite handy if you when editing your alignment sets as well as it effectively gives you an undo if you accidentally remove the wrong star/point. It can be useful when playing with the polar alignment where you align on a quite a few stars either side of the meridian and then pick those that give you the best 'matching' triangles and delete the rest.

To save an alignment set as a duplicate, first load it then switch the preset and click the [Save] button. You can then select another preset and click the [Save] button again creating as many backups as you wish.

Different presets can be used to store different alignment datasets based upon the following:

Presets may be useful for observatory mounts where, for example, preset 1 uses one set of N-Point data, preset 2 uses a different set of N-Point data.

Perhaps preset 1 is a set of N-Point data gathered at the north-eastern side of the observatory while preset 2 is a set of points on the western side. Preset 3 could be a combination. Preset 4 could be the entire sky. Preset 5 could be just three points, and so on.

If we consider for example mount/scope/dovetail flexures induced due to extra equipment mounted on the scope in the data gathering, preset 1 could be settings for DSLR body camera (or bigger camera) setup and preset 2 could be settings for a “small camera” such as webcam. It may not be advisable to maintain a single N-Point database if the user keeps on swapping/replacing the hardware options mounted on the scope due to the different flexure mechanics induced by these add-ons (which is also different depending on where the scope is pointed at). Each (from a high accuracy standard) should have a dedicated N-Point database.

/home/welshdra/public_html/eqmod/data/pages/saving_n-point_alignment_data.txt · Last modified: 2010/08/21 16:38 (external edit)
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