Reducing Inclinometry Data

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Reducing Inclinometry Data

Inclinometry reduction is accomplished on the summit Vaxes (mwtred) using DCL commands and Fortran codes. In summary : the tilting of the antenna at several places is measured and stored in the raw inclinometry data files called INCRED.dat or INC970304.dat or some such. From these data we must calculate (yaw,roll,pitch) as a function of azimuth. These numbers are then stored in a lookup table called MODEL1.dat in jcmtdata_dir and accessed by the TEL task in order to correct the pointing in az & el.

This document describes how to get from the data to the model.

Processing of raw inclinometry data is accomplished by OPERATOR using the INCRED command. This may be done either in the directory in which the raw data were taken, or, better for bookkeeping, on copies of these files in, eg, jcmt_seed:[inclinometry.9703].

After ensuring (by editing) that the first (11) lines at the start of data sets have the form

Header
ncols
name_col_1
name_col_2
etc - - - to name_col_ncols (normally ncols=9)

the options presented by INCRED are

check format & correct for temperature, overlap, and scale
make new model
display data or models
means & differences of data or models
histograms & statistics of data or models

The minimum processing required to take a (edited) dataset to a file in the format of MODEL1 via INCRED involves running options 1 and 2. Option 3 will allow displays at any time of data or model, and options 4 and 5 allow simple comparisons, combinations and analyses.

Option 99 allows more obscure processing.

The new model must be copied, by OPERATOR, into jcmtdata_dir and the TEL task reloaded in order to use the new model.

imc@jach.hawaii.edu

Updated: 03 March 1997

Contact: Iain Coulson. Updated: Sat Nov 6 18:00:32 HST 2004

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