Several rms values for one spectrum

[flor.allaert@…]

Hi,

I'm reducing Mopra data taken in position-switching mode. After removing the bad scans and performing the quotient calculation, I merged the relevant scantables, time-averaged the whole bunch and finally averaged both polarisations. When I plot the resulting 'scantable', I get one single spectrum (as expected). However, when I use the task 'stats' to get the rms depth, it gives me several different values, corresponding to different times. Is this normal? And if so, how should I interpret these values?

Thanks, Flor

[Malte Marquarding]

This is expected behaviour if you selection contains more then one row (spectrum). can you put up scantable.summary() for this scan please.

[flor.allaert@…]

I know the selection contains more than one row (six in this case), but I don't understand why this is and why the plotter only shows me one spectrum...

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Scan Table Summary

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Project: IC2531_R Obs Date: 2012/06/26/01:52:10 Observer: FA Antenna Name: ATMOPRA Data Records: 6 rows Obs. Type: RF TR Beams: 1 IFs: 4 Polarisations: 1 (stokes) Channels: 586 Flux Unit: K Abscissa: LSRK Frequency (GHz) Selection: none

Scan Source Time range Int[s] Record SrcType FreqIDs MolIDs

Beam Position (J2000)

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0 IC2531 2012/06/26/04:42:37.8 - 02:51:28.5 22928.3 6 [PSON] [4] [0]

0 09:59:53.3 -29.35.10.4

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FREQUENCIES: 1

ID IFNO Frame RefVal RefPix Increment Channels POLNOs

4 2 LSRK 1.1307479e+11-0.46428571 3773864.5 586 [0]

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MOLECULES:

ID RestFreq Name

0 [0] []

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[Malte Marquarding]

To see all spectra in a scan you need to set plotter.set_mode('i','t') This will show you all the cycles in the scan.

The following gives you a list of times,rms pairs for all cycles in a scan.

scan.set_selection(ifs=i)
cycles_rms = map(None, scan.get_time(), scan.stats('rms'))
print cycles_rms