- Star Tpoint In the directory with the .dat file output by rstarwrite
TPOINT ready for use: type HELP for assistance, END to quit.
- Load in the Tpoint data file.
* indat file.dat
35 52 8.4 2001 5 30
14 16 0.00 19 12 0.00 20 20 30.00 164 4 0.00 13 40.87
A list of all the stars logged should be printed to the screen.
- Set Tpoint to adjust star positions to fit telescope positions. This is
the modelling that schierd uses.
* adjust s
Model will adjust stars to fit telescope.
- First, have Tpoint fit to the index offsets for the ra and dec axes. The
``use'' feature tells the Tpoint to fit the stars to these particular variables.
* use ih id
- Next, do the fit to these parameters. The fit command should be run
several times, until the errors reported stop shrinking.
coeff change value sigma
1 IH -0.000-319288.44 852.791
2 ID -0.000 -12374.29 654.834
Sky RMS =1464.25
Popn SD =1890.34
When the ``change'' column sits at 0, you can move on.
- Fix the index offsets with fix, and now have Tpoint use the
collimation and polar alignment errors for its next fit.
* fix ih id
* use np ch me ma
- Fit with the fit command several more times until the change goes
to 0, as before.
- Use the whole suite of parameters, by unfixing IH and ID and
fit several more times until Tpoint settles on a solution.
* use ih id
- Save the model to disk and exit.
* outmod modelfile.dat
- The model file can now be viewed with a textfile viewer to extract
notable parameters, or can be used verbatim by schierd.conf as described
in Section 3.8. The model file should look something like the
S 1862248.2854 0.000 0.0000
IH -320481.5133 114.58002
ID -15074.2754 15.45639
NP -284.0514 24.71350
CH -356.0703 109.36628
ME -2233.0871 18.88705
MA -728.2158 9.84367
The column to the right of the fit parameter names contains the fit values, in
arcseconds. The third column contains the rms error in the fit for that parameter.