[1636] | 1 | ======================== |
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| 2 | Tutorial #1 - Basic ASAP |
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| 3 | ======================== |
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| 4 | |
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| 5 | .. sectionauthor:: Kate Brooks |
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| 6 | |
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| 7 | **Main goal:** Get a basic understanding of ASAP commands to import and plot data |
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| 8 | |
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| 9 | Files |
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| 10 | ----- |
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| 11 | |
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| 12 | * 2008-03-12_09320-M999.rpf Data file (1.1 Mb) |
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| 13 | |
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| 14 | |
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| 15 | Data Log |
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| 16 | -------- |
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| 17 | |
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| 18 | * ON-OFF Position switching mode with Mopra |
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| 19 | |
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| 20 | * 2 Scans (1 OFF and 1 ON) |
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| 21 | |
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| 22 | * 1 MOPS Zoom band |
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| 23 | |
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| 24 | Instructions |
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| 25 | ------------ |
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| 26 | |
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| 27 | 1. Work through the list of commands given in the text file to |
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| 28 | calibrate data taken with the Mopra telescope. Commands |
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| 29 | should be typed line-by-line into ASAP. Seek help from the |
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| 30 | tutors if there are any commands you don't understand. |
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| 31 | |
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| 32 | To start asap simply run the following at your prompt:: |
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| 33 | |
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| 34 | asap |
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| 35 | |
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| 36 | 2. Write a python script to automate the calibration procedure |
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| 37 | used in step 1. Your python script should permit interaction |
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| 38 | with the plotter and should be executed in a terminal (and not |
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| 39 | within ASAP) with the following command:: |
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| 40 | |
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| 41 | python -i myscript.py |
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| 42 | |
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| 43 | The python script to be run outside asap needs to have the following line |
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| 44 | at the top of the file:: |
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| 45 | |
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| 46 | from asap import * |
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| 47 | |
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| 48 | This will import all asap functionality into the "normal" python. |
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| 49 | |
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| 50 | Commands |
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| 51 | -------- |
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| 52 | |
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| 53 | .. code-block:: python |
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| 54 | |
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| 55 | # Load data file into memory and view description |
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| 56 | s = scantable('2008-03-12_0932-M999.rpf') |
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| 57 | print s |
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| 58 | |
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| 59 | # Set the plotting mode |
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| 60 | plotter.set_mode(stacking='i', panelling='t') |
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| 61 | |
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| 62 | # Plot all raw data |
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| 63 | plotter.plot(s) |
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| 64 | |
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| 65 | # Set the doppler convention |
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| 66 | s.set_doppler('RADIO') |
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| 67 | |
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| 68 | # Set the rest frame |
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| 69 | s.set_freqframe('LSRK') |
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| 70 | |
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| 71 | # Set the observed rest frequency in Hz |
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| 72 | s.set_restfreqs([86243.37e6]) |
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| 73 | |
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| 74 | # Define the channel unit |
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| 75 | s.set_unit('km/s') |
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| 76 | |
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| 77 | # Form the quotient spectra |
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| 78 | q=s.auto_quotient() |
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| 79 | |
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| 80 | # Average all scans in time, aligning in velocity |
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| 81 | # Note: That for this dataset there is only 1 scan and so this step is redundant |
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| 82 | av = q.average_time(align=True) |
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| 83 | |
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| 84 | # Average the two polarisations together |
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| 85 | iav = av.average_pol() |
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| 86 | |
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| 87 | # Plot the spectrum |
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| 88 | plotter.plot(iav) |
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| 89 | |
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| 90 | # Remove the baseline (set to 0 order). Specify the signal-free channels |
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| 91 | msk = iav.create_mask([-200,-50],[50,180]) |
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| 92 | iav.poly_baseline(msk,0) |
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| 93 | plotter.plot(iav) |
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| 94 | |
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| 95 | # Smooth the data with boxcar, full width = 3 |
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| 96 | siav = iav.smooth(kernel = 'boxcar', width = 3, insitu = False) |
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| 97 | plotter.plot(siav) |
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| 98 | |
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| 99 | # Scale the data according to scaling fudge factor |
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| 100 | # Eg. With beam efficiency of 0.49 at 86 GHz |
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| 101 | iav.scale(2) |
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| 102 | |
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| 103 | # Make final plot for saving |
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| 104 | plotter.set_range(-20,30) |
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| 105 | plotter.plot(siav) |
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| 106 | plotter.set_legend(mode=-1) |
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| 107 | plotter.set_title(['Orion-SiO'], fontsize=18) |
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| 108 | plotter.text(10,95,"SiO (2-1 v=1) at 86243.440 MHz", fontsize=12) |
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| 109 | plotter.text(-19,95,"2008/03/12", fontsize=12) |
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| 110 | plotter.text(-19,90,"Zoom Mode", fontsize=12) |
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| 111 | |
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| 112 | # Save plot as postscript file |
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| 113 | plotter.save('Orion-SiO.ps') |
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