Atacama Pathfinder EXperiment APEX
LABOCA Calibration
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Array parameters September 2009 (16/09-11/10)

After LABOCA was warm for a few days mid-September because of technical problem, it was cooled down again to operational temperature on the 16th of September.

The instrument was warmed up at 11th of October, at the beginning of the MPI observing time block.

Again no mechanical changes have been performed at the instrument, thus the channel offsets are not expected to have changed compared to previous months.

Main parameter file: laboca-2009-09.rcp

Individual scans

Scan #Date Parameter fileArray plotIndividual channel maps
61119 2009-09-18T04:07 Uranus_61119_Laboca.rcp array_61119.pdf beams_61119.pdf
67403 2009-10-04T10:38 Mars_67403_Laboca.rcp array_67403.pdf beams_67403.pdf
68809 2009-10-08T02:41 Uranus_68809_Laboca.rcp array_68809.pdf beams_68809.pdf

Notes on individual channels

Note:Channels which are terminated with a resistor are not listed in the following table anymore.

Channel #Description
101, 103, 106, 110 Strong cross-talk: 101↔106 and 103↔110.
81, 82, 83, 84, 85, 86, 89, 90, 91, 92, 93, 94, 96, 136, 159, 160 Channels located in group 4 / cable M. Channels 82, 86, and 90 don't show signals, they are always considered bad. Channels 92, 93, 94, and 136 are variable (sometimes bad). The remaining ones sometimes show excess noise (like in scan 68809), or at least cross-talk (about 20% level) with channels 92 and sometimes 92 (like in scan 67403). Check your data to see if they are usable.
177, 179, 180, 182, 183-185, 191, 192, 201, 202, 203, 205, 207, 217, 218, 220 Channels located in group 7 / cable A. These channels show problems for a while already. In scan 68809, they all don't show astronomical signal and are considered bad. For the earlier scans, some are suffering only from cross-talk on a 20% level (177, 179, 182, 192, 202, 204, 205, 218, 220). Check your data.
6, 228, 257, 309 Bad channels, not showing any astronomical signal or very low signal levels, unconnected to groups 4 or 7 above.
241 No proper signal. Picks up signal from channels 248 (strong) and 296 (weak).

channel_flags-2009-09.boa:

# 25 channels not connected to any bolometer
not_connected = [ 29,  33,  35,  40,  64,  66, 124, 135, 142, 144, 146, 151, 158,
                 189, 193, 195, 200, 224, 226, 284, 295, 302, 304, 306, 311 ]
# 20 channels with 1MOhm resistor
resistor = [  15,  16,  87,  88,  95, 139, 143, 145, 149, 150, 157, 178,
             181, 186, 187, 188, 190, 255, 310, 317 ]
# 2 channels sealed with an absorber
blind = [ 4, 163 ]
sealed = blind
# channels showing strong cross-talk
cross = [ 101, 103, 106, 110, 241 ]
# Bad channels (no/low signal)
bad = [  6,  82,  86,  90, 180, 183, 184, 185, 191, 201, 203, 207, 217, 228,
       257, 309 ]
# Variable channels (sometimes bad or cross-talk)
bad_maybe = [ 92, 93, 94, 136, 177, 179, 182, 192, 202, 204, 205, 218, 220 ]
# remaining channels on Cable M. Cross-talk on a 20% level or somewhat noisy.
cable_M = [  81,  83,  84,  85,  89,  91,  96, 159, 160 ]