OTF-Geometry Help

An OTF geometry has 3 purposes :

1. Identify which pixels are "valid", doubles, off, weird, because this information does not come easy from the instrumental setup

2. Determine where each pixel lies on the grid

3. Determine the Nasmyth coordinates of each of these pixels

4. Save all these information in the appropriate format.

Once items 1 and 2 are completed (see below, I save the best part for the end...), steps 3 and 4 are performed routinely by otf_geometry.pro. The information about kids selection and location on the grid is passed to the routine by info.kidpar_ref, e.g. '0061_20121115'. If you are happy with this selection, you can apply it to any otf_geometry scan. Note though, that by default, otf_geometry will look for the selection relevant to the current scan.

Items 1 and 2 are the most time consuming. The most efficient way to perform them so far is with select_kids_per_matrix.pro that will display an IDL widget that allows the user to have a picture of each kid map and discard unsafe pixels with a single mouse click and align the beams on a grid. For yet unclear reasons, it is impossible to run this script on sami: the time lag between actions and display prevents any interactive action with the widgets. So, if you have to select kids, you have to:

a. scp the .fits data of the scan to a local machine on which the NIKA software runs correctly

b. follow otf_geometry_help.pro, i.e. crunch the data to produce the required .save files, launch select_kids_per_matrix, do the selection. DO NOT FORGET TO EXIT IDL ONCE YOU ARE DONE WITH THE FIRST MATRIX BEFORE WORKING ON THE SECOND MATRIX.

c. scp the .save output of select_kids to sami (see otf_geometry_help)

d. following otf_geometry_help.pro, you may now do steps 3 and 4 with otf_geometry.pro

e. scp the output .fits files to SAMI.

Note that, of course, steps d. and e. can be performed directly on SAMI.

OTFGeometryHelp (last edited 2012-11-17 18:23:33 by NikaBolometer)