The FIT9 pointing data analysis package

Prior to the installation of the new TCS in Aug 2000, JCMT pointing data, in the form shown here , was analysed using the FIT9 program, originally written for 7 parameters by Sidney Kenderdine in the 1980's (see MTUN005 ). The program is still available on the summit VAX by typing the command

          jpoint

and selecting option 8, which calls the DCL handler FIT9.com, and thence the Fortran code FIT9.for. You may then enter the filename of the data (as generated by pointextract and having the form ptyymmdd_hh.dat), and select any subset of the data (by front-end or elevation) for analysis. You are then asked which of the 9 parameters you wish to optimize (fix = 'do not optimize') and you get to see the current values of the model parameters and the suggested changes following the least-squares fit. You also see the overall rms errors before and after the fit. If you offer a name for the output file, the data are corrected onto the new model, ready for display using option 2 of the jpoint package.

These (7) model parameters are related (mainly 1:1 but occasionally with a sign change) to the 7 parameters of the TPOINT model - see here.