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 * Check the array-offsets for stability.
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 * Check the array-offsets for stability.
How are the data checked with mopsic?? (CK)

Flatfield observation

Aim: derive parameters of the 117ch array, i.e. the sensitivity of each pixel and relative offsets of the pixels.

A flatfield observation must be done at least once per pool session. This observation must be carried out during nights only under very stable weather conditions (tau of 0.5 is ok though). If the conditions are not such stable the flatfield should be redone.

Low tau is not so important, but stable pointing is.

In case MAMBO2 or the mirrors in front of it are readjusted, several flatfields must be done several times.

If not suitable planets are up during the night a strong (10Jy/beam) point source somewhere between 50 and 70 deg (e.g. J1229+021). The source should be point-like (e.g. Uranus and Mars, but not Saturn or Jupiter!).

  • IMPORTANT: Old p4/p5 values can cause a drift in the array parameters, which will make the data useless.

  • A pointing and a focus must be done before and after the map

  • Map procedure
    • pako> source J1229+021 !Already done before

      pako> roff53 !Central channel for maps

      pako> rcpmap

      pako> start

In detail, the rcpmap procedure is:

  • bsw 46 bmap 360 290 5 6

The duration of this map is (290/5)*360 ~ 1hr.

  • Check the array-offsets for stability.

How are the data checked with mopsic?? (CK)

FlatField (last edited 2009-11-19 10:44:57 by gra-lx17)