takahashi mount
takahashi mount
Anyone here know what is the meaning of USD on takahashi mount?? how to know or calculate periodic error on a mount? thanks alot.
Hi Jingguo
Arief is right on the acronym.
However i dont see its why it is labelled USD when max slew speed is limited to 50X on earlier models.
PE can be accurately determined with a bright star, webcam with 1.25 nosepiece and K3CCD (drift explorer). It is also crucial that mount need to be fairly well polar aligned.
There are a few parameters that must be furnished in K3CCD prior to the PE measurement, such as focal length and CCD pixel size.
Once everything is in place and star is position within FOV of webcam. Drift explorer of K3CCD would then be able to record the PE as a log file. Preferably record 30min or more so as to capture at least 3 periodic cycles to even out variation. Use Excel or equivalent spreadsheet to open the log file for PE chart plotting.
Have fun
Matthew
Arief is right on the acronym.
However i dont see its why it is labelled USD when max slew speed is limited to 50X on earlier models.
PE can be accurately determined with a bright star, webcam with 1.25 nosepiece and K3CCD (drift explorer). It is also crucial that mount need to be fairly well polar aligned.
There are a few parameters that must be furnished in K3CCD prior to the PE measurement, such as focal length and CCD pixel size.
Once everything is in place and star is position within FOV of webcam. Drift explorer of K3CCD would then be able to record the PE as a log file. Preferably record 30min or more so as to capture at least 3 periodic cycles to even out variation. Use Excel or equivalent spreadsheet to open the log file for PE chart plotting.
Have fun
Matthew