Three-axis Telescope Control

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Three Axis Telescope Control

Simulation Software

In order to better understand the motion of the three-axis mount, I wrote a graphical simulation of its motion. A screenshot of the simulator is shown below.

The simulator is available in several formats:

The software allows you to manipulate the telescope using several different coordinates. Direct control of the telescope axes is done through the a1, a2, and a3 sliders. As these sliders are moved, the altitude, azimuth, hour angle, declination, and field rotation sliders will be updated appropriately. If the field rotation slider is adjusted, the telescope will remain pointed at the same location in the sky, but will rotate about its optical axis. If the altitude, azimuth, hour angle, or declination sliders are adjusted, the telescope will move to point at the new position while keeping the field rotation constant.

Some interesting experiments to try with the simulator are:

Point the telescope at any location and adjust the field rotation. This demonstrates how the mount is capable of providing arbitrary field rotation at any point in the sky.
Point the telescope at the pole (azimuth = 0, altitude = latitude) and slowly increase the hour angle. This simulates the telescope tracking at the pole over time.
Point the telescope 10 degrees below the pole (azimuth = 0, altitude = latitude - 10) and slowly increase the hour angle. This simulates the telescope tracking around the pole over time.
Point the telescope at the meridian (a1 = 90, a2 = latitude, a3 = 270) and adjust the hour angle. Note that the mount only needs to move the a1 axis to keep the field rotation constant while in this position.

If anyone has any other interesting test cases, please email me about them.