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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