Nov. 29 2012, RZ

The reference pixel used for pointings and foci is quite unstable and even changes the position.

The figure below shows the 2mm data after subtraction of a "common mode". The reference pixel 15 (counting from 1 for the 2mm array) shows strong instabilities.

instability of the 2mm ref. pixel #15

It even does change the position, as shown in the figure below.


This instability affects significantly the focus and pointing results. In the figure below the elev-subscans do not show the source because of this effect and not the variable atmosphere. The source is clearly visible in the upper right image - with a signal as in the azim-subscans.

instability of the ref. pixel during a pointing

ReliabilityRefPixels (last edited 2012-11-29 10:24:42 by NikaBolometer)