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LABOCA Calibration
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Array parameters July 2009 (12/06-30/07)

After being warm for to weeks at the beginning of June, LABOCA was cooled down to operational temperature again starting on the 12th of June. Since then it has been used by all partner institutes. No mechanical works have been performed on the instrument while it was warm, thus the channel parameters should not have changed much compared to May 2009.

Starting with this period Mars can be used again for beam maps, after having been too close to the sun for several weeks. Thus a better accuracy can be expected for the channel offsets than with Saturn.

On 30th of July, we started to warm up LABOCA, in order to save liquid Helium. The instrument was not used during the first half of August.

Main parameter file: laboca-2009-07.rcp

Individual scans

Scan #Date Parameter fileArray plotIndividual channel maps
35493¹ 2009-06-23T01:35 Saturn_35493_Laboca.rcp array_35493.pdf beams_35493.pdf
38084 2009-07-02T14:07 Mars_38084_Laboca.rcp array_38084.pdf beams_38084.pdf
45961 2009-07-30T08:08 Uranus_45961_Laboca.rcp array_45961.pdf beams_45961.pdf
 ¹ Scan 35493 is unusable. It was observed at very low elevation, and the telescope pointing changed by 10″ during the map, which is reflected in the offsets of the channels with largest Elevation distance from the array center.

Notes on individual channels

Channel #Description
101, 103, 106, 110 Strong cross-talk: 101↔106 and 103↔110.
81, 82, 83-85, 86, 87-96, 135, 136, 142, 145, 150, 151, 157-160 Channels located in group 4 / cable M. Unless they are terminated with a resistor anyway, they all show low signal levels and/or cross-talk in-between, depending on the date.
6, 82, 86, 182, 191, 201, 203, 205, 207, 217, 228, 309 Bad channels not showing any astronomical signal, very low signal levels, or high noise.
179, 180, 184, 185, 192, 218, 220, 294 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-2009-07.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, 182, 191, 201, 203, 205, 207, 217, 228, 309 ]
# Variable channels
bad_maybe = [ 179, 180, 184, 185, 192, 218, 220, 294 ]
# 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, 160 ]