A Simple Tpoint Model

To create a simple Tpoint model, begin by following steps 1-5 in Section 5.2.2. Continuing from there, follow the steps below:

1. Repeat for several stars, certainly at least 4, perhaps 5.
2. Output the file with rstarwrite.
3. Create a pointing model as described in Section 5.3.
4. Use the ME and MA values in the model to find the polar offset.

   The units of ME and MA are in arcseconds. Here I quote from the Tpoint documentation:

   • MA       Polar Axis Misalignment in Azimuth

     In the northern hemisphere, positive MA means that the pole of the mounting is to the right of due north.

     In the southern hemisphere, positive MA means that the pole of the mounting is to the right of due south.

   • ME       Polar Axis Misalignment in Elevation

     In the northern hemisphere, positive ME means that the pole of the mounting is below the true (unrefracted) pole. [This is the alignment we have been using, which is easier for our wide-field systems.]

     In the southern hemisphere, positive ME means that the pole of the mounting is above the true (unrefracted) pole.