Alliance for Astronomy, Inc.

The 80cm telescope is on an alt-az mount with a fully go-to drive system.  The drive system is by Sideral Technology, Inc that features servo controlled alt axis, az axis and field de-rotator control (focuser coming soon).  The telescope has a rotating turret eyepiece holder that holds three Nagler eyepieces of 9 mm, 13, mm and 20 mm.  There is a wide-field 30 mm eyepiece as well.  All eyepieces view through a built-in Paracorr coma corrector.  An STL-1001E camera (with its own Paracorr corrector) is used for scientific imaging.  Currently, the camera holds Johnson-Cousins V and Ic filters (with room for two or three more).

With the Paracorrs in place the effective focal length of the telescope is 3,600 mm (F/4.5).  The STL-1001E camera has 1024×1024 pixels of 24 microns square dimensions.  The resulting resolution is 1.37 arc sec/pixel in a field of view of 23.5 x 23.5 arc min.  A full-resolution image downloads in 4 seconds.

The Sideral Technology control program creates a model of the mount that accounts for mis-alignments in the various axes, the optical axis, the orientation of the mount on the ground, etc.  Currently, the RMS pointing accuracy of the mount is some 5 arc min.  This is more than adequate to place any target on the chip of the camera or in the field of the 30 mm eyepiece but improvement appears possible with the substitution of higher resolution telescope encoders (currently at 12,000 on the Az axis and 8,192 on the El axis).  Below are some graphical visualizations of the mount errors.

Graph showing location of calibration points.  The outer circle represents the horizon and the center point represents the zenith.	Graph showing errors in pointing of the calibration points.  The RMS error is just over 5 arc min and the largest error (of 18 measured) was just over 9 arc min.