source: branches/alma/tutorials/tutorial_1.rst@ 2659

Last change on this file since 2659 was 1757, checked in by Kana Sugimoto, 14 years ago

New Development: Yes

JIRA Issue: Yes (CAS-2211)

Ready for Test: Yes

Interface Changes: Yes

What Interface Changed: ASAP 3.0.0 interface changes

Test Programs:

Put in Release Notes: Yes

Module(s): all the CASA sd tools and tasks are affected.

Description: Merged ATNF-ASAP 3.0.0 developments to CASA (alma) branch.

Note you also need to update casa/code/atnf.


File size: 2.7 KB
RevLine 
[1636]1========================
2Tutorial #1 - Basic ASAP
3========================
4
5.. sectionauthor:: Kate Brooks
6
7**Main goal:** Get a basic understanding of ASAP commands to import and plot data
8
9Files
10-----
11
12* 2008-03-12_09320-M999.rpf Data file (1.1 Mb)
13
14
15Data Log
16--------
17
18* ON-OFF Position switching mode with Mopra
19
20* 2 Scans (1 OFF and 1 ON)
21
22* 1 MOPS Zoom band
23
24Instructions
25------------
26
271. Work through the list of commands given in the text file to
28 calibrate data taken with the Mopra telescope. Commands
29 should be typed line-by-line into ASAP. Seek help from the
30 tutors if there are any commands you don't understand.
31
32 To start asap simply run the following at your prompt::
33
34 asap
35
362. Write a python script to automate the calibration procedure
37 used in step 1. Your python script should permit interaction
38 with the plotter and should be executed in a terminal (and not
39 within ASAP) with the following command::
40
41 python -i myscript.py
42
43 The python script to be run outside asap needs to have the following line
44 at the top of the file::
45
46 from asap import *
47
48 This will import all asap functionality into the "normal" python.
49
50Commands
51--------
52
53.. code-block:: python
54
55 # Load data file into memory and view description
56 s = scantable('2008-03-12_0932-M999.rpf')
57 print s
58
59 # Set the plotting mode
60 plotter.set_mode(stacking='i', panelling='t')
61
62 # Plot all raw data
63 plotter.plot(s)
64
65 # Set the doppler convention
66 s.set_doppler('RADIO')
67
68 # Set the rest frame
69 s.set_freqframe('LSRK')
70
71 # Set the observed rest frequency in Hz
72 s.set_restfreqs([86243.37e6])
73
74 # Define the channel unit
75 s.set_unit('km/s')
76
77 # Form the quotient spectra
78 q=s.auto_quotient()
79
80 # Average all scans in time, aligning in velocity
81 # Note: That for this dataset there is only 1 scan and so this step is redundant
82 av = q.average_time(align=True)
83
84 # Average the two polarisations together
85 iav = av.average_pol()
86
87 # Plot the spectrum
88 plotter.plot(iav)
89
90 # Remove the baseline (set to 0 order). Specify the signal-free channels
91 msk = iav.create_mask([-200,-50],[50,180])
92 iav.poly_baseline(msk,0)
93 plotter.plot(iav)
94
95 # Smooth the data with boxcar, full width = 3
96 siav = iav.smooth(kernel = 'boxcar', width = 3, insitu = False)
97 plotter.plot(siav)
98
99 # Scale the data according to scaling fudge factor
100 # Eg. With beam efficiency of 0.49 at 86 GHz
101 iav.scale(2)
102
103 # Make final plot for saving
104 plotter.set_range(-20,30)
105 plotter.plot(siav)
106 plotter.set_legend(mode=-1)
107 plotter.set_title(['Orion-SiO'], fontsize=18)
108 plotter.text(10,95,"SiO (2-1 v=1) at 86243.440 MHz", fontsize=12)
109 plotter.text(-19,95,"2008/03/12", fontsize=12)
110 plotter.text(-19,90,"Zoom Mode", fontsize=12)
111
112 # Save plot as postscript file
113 plotter.save('Orion-SiO.ps')
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