Atacama Pathfinder EXperiment APEX
SABOCA Calibration
MPIfR Bonn   ESO   Onsala Space Observatory
  APEX TWIKI CONTACT SEARCH HELP NEWS DISCLAIMER

Home > Instrumentation > SABOCA > SABOCA Calibration > Array parameters

Array parameters May 2008 (10/05-17/05)

Main parameter file: saboca-2008-05.rcp

Individual scans

Scan #Date Parameter fileArray plotIndividual channel maps
15426 2008-05-13T22:55 Mars_15426_Saboca.rcp array_15426.pdf beams_15426.pdf
15427 2008-05-13T23:03 Mars_15427_Saboca.rcp array_15427.pdf beams_15427.pdf
15437 2008-05-13T23:29 Mars_15437_Saboca.rcp array_15437.pdf beams_15437.pdf
15438 2008-05-13T23:37 Mars_15438_Saboca.rcp array_15438.pdf beams_15438.pdf
15442 2008-05-13T23:52 Mars_15442_Saboca.rcp array_15442.pdf beams_15442.pdf

Notes on individual channels

In SABOCAs first commissioning run during May 2008, most of the 37 channels were working properly. Also note that the output signal is negative (for technical reasons), thus the signal has to be inverted. Channel 21 and 25 show positive signal sometimes or always, respectively.

Channel #Description
2 Cross-talk. Doesn't show corresponding signal, but picks up (low) signal from channel 9. Unusable.
13, 30 No astronomical signal. They are considered bad.
10, 24 Just noise. Channel 24 also picks up signal from channel 23. Unusable.
21 Variable (bad for scan 15427). Also positive signature part of the time. Check your data.
25 Variable. Positive signature, also cross-talk with channel 23. Unusable (at least for extended sources).
4, 6, 12, 14, 22, 23, 26, 28 Variable channels. They sometimes show high noise or spikes. Check your data, can be easily identified if bad.

channel_flags-2008-05.boa:

# Inverted channels:
def invertSomeChannels():
    for i in range(len(inverted)):
        num=inverted[i]-1
        data.Data[:,num] *= array(-1,'f')
inverted = range(1,25) + range(26,38)
invertSomeChannels()

# Bad channels (no signal or noisy)
bad = [  2, 10, 13, 24, 30 ]
# Variable channels - Check your data and add to bad if appropriate:
bad_maybe = [14, 21, 23, 25, 28 ]
# Channels which sometimes show spikes - despike and/or add to bad if appropriate:
spiky_maybe = [  4,  6, 12, 22, 26 ]
flagC(bad)