Re: Question from a prospective buyer: All Star Polar Alignment


It is possible to use the ExploreStars alignment transform matrix coefficients (shown by turning on Show Alignment Data under Settings Preferences) to calculate the offset in Altitude and Azimuth of the mount. 

The technique would involve calculating the offset in ALT/AZ and then pointing the mount to a bright star adjusting for the calculated offset values. Then you would manually move the ALT/AZ controls to center the star and that would be it. Once you have manually adjusted the ALT/AZ then you would clear the alignment since you have now physically aligned the mount.

Pretty straight forward. I have worked on that math before but would need to refresh my memory and work on a spreadsheet version of the calculation to test it out. Unfortunately, I don't know when I would be able to spend time on it since I have probably 6 other priorities that I am working on currently 

If anyone is interested in working on this, here is the reference paper I used to create the Alignment function in the ExploreStars application. 

If you are interested in taking on this project (not easy!) I would suggest getting familiar with the equations and then derive a method to convert the transform coefficients to an offset in ALT/AZ coordinates. I use an open source library to do the matrix transform calculations called MathNet Numerics:

This really simplifies the work. I have this on my TODO list but I probably won't be able to get it done for a few months yet.


Jerry Hubbell
Director Electrical Engineering
Explore Scientific, LLC.

---In ESPMC-Eight@..., <joe@...> wrote :

Celestron's competing CGX mount eschews  a polar scope in favor of their much-touted, "exclusive" All Star Polar Alignment

Celestron certainly deserves kudos for a clever idea which I understand works very well.  Celestron doesn't share its code, but the idea is sufficiently general that it shouldn't be patentable.  Is a PMC-8 implementation in the works?  

Every go-to scope manufacturer with sufficient compute power in their scope's processors should be able to implement the idea.  I think it will be common in the near future.  

A PMC-8 implementation affects the choice of whether to purchase an expensive ~$240 Losmandy G-11 scope accessory.

(Thanks for the responses to my many questions!)

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