Atacama Pathfinder EXperiment APEX
LABOCA Calibration
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Home > Instrumentation > LABOCA > LABOCA Calibration > Array parameters

Array parameters August 2009 (12/08-14/09)

LABOCA was warm in the first half of August. We started to cool it down on 11th of August, and it was used a few days later.

Because of a technical problem with the Helium transfer line, LABOCA could not be filled properly on 14th of September, and - as a consequence - warmed up.

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-2009-08.rcp

Individual scans

Scan #Date Parameter fileArray plotIndividual channel maps
50418 2009-08-17T04:02 Uranus_50418_Laboca.rcp array_50418.pdf beams_50418.pdf
50433 2009-08-17T06:01 Uranus_50433_Laboca.rcp array_50433.pdf beams_50433.pdf
50527 2009-08-19T04:45 Uranus_50527_Laboca.rcp array_50527.pdf beams_50527.pdf

Notes on individual channels

Channel #Description
101, 103, 106, 110 Strong cross-talk: 101↔106 and 103↔110.
81, 82, 83, 84, 85, 86, 87-96, 135, 136, 142, 145, 150, 151, 157-159, 160 Channels located in group 4 / cable M. Unless they are terminated with a resistor anyway, they show low signal levels, high noise, and/or cross-talk in-between, depending on the date.
6, 82, 85, 86, 160, 179, 182, 184, 185, 201, 205, 207, 217, 228, 257, 309 Bad channels not showing any astronomical signal, very low signal levels, or high noise.
177, 180, 183, 192, 202, 203, 204, 218, 220, 222 Variable channels (sometimes bad, sometimes not). Check your data.
241 No proper signal. Picks up signal from channels 248 (strong) and 296 (weak).

channel_flags-2009-08.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,  85,  86, 160, 179, 182, 184, 185, 201, 205, 207, 217, 228, 257, 309 ]
# Variable channels
bad_maybe = [ 177, 180, 183, 192, 202, 203, 204, 218, 220, 222 ]
# remaining channels on Cable M. Bad most of the time, sometimes only cross-talk
cable_M = [  81,  83,  84,  85,  89,  90,  91,  92,  93,  94,  96, 136, 159 ]