SIMBA Parameters

On this page you can find some parameters which have been measured in the lab of the MPIfR Bolometer Development Group.
 


 

Spectral response of SIMBA


Measured with the group's Martin-Puplett FT Spectrometer, after the upgrade in March/April 2002.






 

Deconvolution parameters of each AC coupled SIMBA channel

In the "fastscanning" observing mode, the effect of amplifier AC coupling and bolometer time constant results in a "bolometer filter function" which has to be removed from the raw data by deconvolution. (For details see: Reichertz et al., Astronomy & Astrophysics, 379(2) 735-739, (2001)).

The bolometer filter function can be written as a complex function:

G(f) = 1 / ( (1 + 1 / (i 2 Pi f  tc_amp) )  (1 + i 2 Pi f  tc_bol) )

In order to get the best possible reconstruction of the original signal we have experimentally determined the two parameters tc_amp and tc_bol for each channel. Due to a technical problem in the preamp, five channels had a significantly different AC coupling (channels 33 to 37) when SIMBA was at SEST for the first time. These five channels were changed in April 2002.
 

June 2001 - March 2002
Channel tc_amp[s] tc_bol[ms]
1 1.58 2.29
2 1.62 3.75
3 1.39 1.94
4 1.54 1.95
5 1.46 2.56
6 1.57 2.38
7 1.42 2.89
8 1.48 3.07
9 1.57 2.99
10 1.58 3.13
11 1.58 2.36
12 1.59 2.64
13 1.55 1.76
14 1.52 2.28
15 1.44 1.91
16 1.67 2.35
17 1.49 4.35
18 1.44 4.77
19 1.69 3.74
20 1.68 3.57
21 1.52 2.70
22 1.53 3.61
23 1.64 3.56
24 1.65 3.33
25 1.52 4.33
26 1.59 3.20
27 1.57 2.11
28 1.56 2.72
29 1.57 2.79
30 1.50 2.83
31 1.60 2.89
32 1.42 3.86
33 1.01 1.94
34 1.03 3.51
35 0.98 2.38
36 1.00 1.98
37 1.01 1.96

After the SIMBA upgrade at the MPIfR in April 2002:
 

after April 2002
Channel tc amp [s] tc bol [ms]
1 1.58 2.29
2 1.62 3.75
3 1.39 1.94
4 1.54 1.95
5 1.46 2.56
6 1.57 2.38
7 1.42 2.89
8 1.48 3.07
9 1.57 2.99
10 1.58 3.13
11 1.58 2.36
12 1.59 2.64
13 1.55 1.76
14 1.52 2.28
15 1.44 1.91
16 1.67 2.35
17 1.49 4.35
18 1.44 4.77
19 1.69 3.74
20 1.68 3.57
21 1.52 2.70
22 1.53 3.61
23 1.64 3.56
24 1.65 3.33
25 1.52 4.33
26 1.59 3.20
27 1.57 2.11
28 1.56 2.72
29 1.57 2.79
30 1.50 2.83
31 1.60 2.89
32 1.42 3.86
33 1.38 2.04
34 1.32 3.94
35 1.35 2.52
36 1.31 2.16
37 1.39 2.66


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Page created by Lothar A. Reichertz, April 2002