So here are the steps for a standard astrometry reduction.

- get_data,'2001-03-16.coh' (Read a CONSTRICTOR file with coherent integrations.)
- hds_close
- REDUCEBG DATADEFAULT BG (To make sure every scan has a back ground rate and set it to zero since we don't care about the visibility calibration.)
- REDUCEPOINT DATAASTROMETRYPHASEEDIT (Flag all channels higher than 20 as well as the laser channel 11. Data after about May 2002 only need channel 12 of spectrometer 1 flagged. This is done automatically.)
- flagphase,2,1,chan=indgen(16)+1 Optional flagging of baseline 1 in beam 2, in this example. This is needed if the same baseline occurs twice in the data. In the case of a reference baseline, the one in the first beam would be overwritten by the one in the second beam, and so on, in the dispersion correction procedure.
- REDUCEPOINT DATAASTROMETRYPHASEWRAP (Unwrap the phases as a function of channel.)
- REDUCEPOINT DATAASTROMETRYDISPCORR (Compute dispersion correction.)
- REDUCEPOINT DATAASTROMETRYPLOT (Plot VACDELAY, i.e. the dispersion corrected delay relative to the predicted geometric delay and flag. Use PLOTAUTO. The reference station values are zero by definition.)
- hds_open,'2001-03-16.inch' (Open INCHWORM file.)
- get_metroconfig
- get_motiongroup,1
- hds_close
- pivotfit. An optional step which fits siderostat pivot coordinates. RMS residuals should be on the order of a couple of microns. After this step, plotting ParXYZ corr. will display the residuals (see next step).
- REDUCEINCH DATAPLOT. Plot azimuth versus elevation, connecting data points with lines. Smooth curves should be the result. This is a test whether proper siderostat models are loaded. Also plot ParX,Y,Z to look for outliers.
- REDUCEINCH DATAINIT (For now, we plan on computing and
applying the metrology
correction
*after*averaging, so we have to initialize the metrology correction to zero for the calibrated delays not to be flagged during averaging.) - average
- inchav
- CALIBRATEASTROMETRYMETROCORR (Compute and apply constant term and pivot corrections.)
- CALIBRATEASTROMETRYSOLVE (Compute astrometric solutions)