The mount of choice for a fixed observatory setup.
You can find all technical information on the internet. The beauty of this mount is that it works with a mathematical model of the sky, which it builds using platesolving.
It will slew toward a coordinate set, and then verify with platesolving how much the deviation is to that particular point. In such a way you can build up a model of dozens of points – the more points the more accurate the model.
Next, when tracking, the mount takes into account all deviations and follows the mathematical model rather then just tracking equatorially. For this it uses both axes.
This means that when the mount knows (from the model), that at a certain hight & azimut the wole setup typically bends a bit lower, it will compensate.
This model works great if:
- you have optics that do not shift or move eg a refractor or a maksutov
- the overall rigidity of your OTA is stable
- the overall rigidity of the pier and underground is stable
Sofware like N.I.N.A. has plug-ins that allow for:
- model building including artificial horizons, based on a ‘golden spiral’ ( a distribution over the whole sky of points). Typically that will be the standard model being used. You can save models under a name depending on the application or OTA configuration.
- model building based on a “sidereal path’. This is a model ‘on top’ of an existing model, which will refine the path of the object you image for the next few hours. So starting from the point where the object is currently, it will start plate-solving points along the sidereal path for the next coming hours as you like to image. That super-refines the tracking accuracy.
My experience with the GM2000HPS is with a standard C14. Using this combination you can image objects at the native focal length for 5 minutes without noticeable errors. Pointing accuracy is almost flawless, the only caveat here is the shifting optics of the SCT that will insert an arcminute deviation.