5.2.1.2
Example Configurations
The best way to learn about how to define and perform configurations is through examples. We will discuss how to use the
example configuration definition shown below in an Observing Script in § 5.2.1.3. All of the keywords available for use in
a configuration definition will be discussed in § 5.2.1.4.
Continuum Observations
# configuration definition for continuum observations
continuumconfig = ”””
receiver = ’Rcvr1_2’
beam = ’B1’
obstype = ’Continuum’
backend = ’DCR’
nwin = 1
restfreq = 1400
bandwidth = 80
swmode = ’tp’
swtype = ’none’
swper = 0.2
tint = 0.2
vframe = ’topo’
vdef = ’Radio’
noisecal = ’lo’
pol = ’Linear’
”””
The above configuration definition has been given the name “continuumconfig” and can be used for pointing and focusing
observations or for continuum mapping. For these observations we have selected continuum observations
[obstype=’Continuum’] using the single beam L–band (1 to 2 GHz) receiver [receiver=’Rcvr1 2’; beam=’B1’] and the DCR
as the backend detector [backend=’DCR’]. We wish to take data with a single band [nwin=1] which has an 80 MHz
bandwidth [bandwidth=80] centered on 1400 MHz [restfreq=1400]. We wish to do total power observations [swmode=’tp’;
swtype=’none’] with the time to go through a full switching cycle being 0.2 seconds [swper=0.2]. We want the DCR to
record data every 0.2 seconds [tint=0.2]. We do not wish to Doppler track the rest frequency since these are continuum
observations [vframe=’topo’; vdef=’Radio’]. We would like to use the low-power noise-diode [noisecal=’lo’]. Finally, we
wish to take the data using the linear polarizations, X and Y [pol=’linear’]. If you are unsure as to what is meant by these
keywords then you should see § 5.2.1.4.
44 CHAPTER 5. INTRODUCTION TO SCHEDULING BLOCKS AND OBSERVING SCRIPTS
Spectral Line, Frequency Switching Observations
# configuration definition for spectral line observations
# using frequency switching
spectralfsconfig = ”””
receiver = ’Rcvr1_2’
beam = ’B1’
obstype = ’Spectroscopy’
backend = ’SpectralProcessor’
nwin = 1
restfreq = 1420
bandwidth = 10
swmode = ’sp’
swtype = ’fsw’
swper = 1.0
swfreq = 0 , −2.5
tint = 2.0
vframe = ’lsrk’
vdef = ’Radio’
nchan = ’high’
sp.mode = ’Square’
noisecal = ’lo’
pol = ’Linear’
”””
The second configuration definition will be named “spectral fs config” and can be used for spectral line observations
[obstype=’Spectroscopy’] using frequency switching [swmode=’sp’; swtype=’fsw’]. For these observations we wish to use
the single beam L–band (1 to 2 GHz) receiver [receiver=’Rcvr1 2’; beam=’B1’] and the Spectral Processor as the backend
detector without cross-polarization products [backend=’SpectralProcessor’; sp.mode=’Square’]. We wish to take data with a
single band [nwin=1] which has a 10 MHz bandwidth [bandwidth=10] centered on 1420 MHz [restfreq=1420] with the
highest number of spectral channels available [nchan=’high’]. We wish the cycle time to go through a full switching cycle to
be 1 second [swper=1.0] while we wish the frequency switching states to be centered on the line and then shifted by -2.5
MHz [swfreq=0,-2.5]. We want the Spectral Processor to record data every 2 seconds [tint=2.0]. We wish to Doppler track
the spectral line in the commonly used Local Standard of Rest velocity frame [vframe=’lsrk’; vdef=’Radio’]. We would like
to use the noise-diode with the lower equivalent system temperature [noisecal=’lo’]. Finally, we wish to take the data using
the linear polarizations, X and Y [pol=’linear’].
5.2. COMPONENTS OF AN OBSERVING SCRIPT 45
Multiple Spectral Lines, Position Switching Observations
# configuration definition for multiple spectral line observations
# using position switching
spectralpsconfig = ”””
receiver = ’Rcvr8_10’
obs type = ’Spectroscopy’
backend = ’Spectrometer’
nwin = 4
restfreq = 9816.867 , 9487.824 , 9173.323 , 8872.571
deltafreq = 0 , 0 , 0 , 0
bandwidth = 12.5
swmode = ’tp’
swtype = ’none’
swper = 1.0
tint = 30
vlow = 0
vhigh = 0
vframe = ’lsrk’
vdef = ’Radio’
noisecal = ’lo’
pol = ’Circular’
nchan = ’medium’
spect.levels = 9
”””
The third configuration definition to be considered has the name “spectral ps config” and can be used for spectral line
observations [obstype=’Spectroscopy’] using position switching [swmode=’tp’; swtype=’none’]. For these observations we
wish to use the single beam X–band (8 to 10 GHz) receiver [receiver=’ Rcvr8 10’; beam=’B1’] and the Spectrometer as the
backend detector without cross-polarization products [backend=’Spectrometer’]. We wish to take data on multiple spectral
lines [nwin=4], each having a 12.5 MHz bandwidth [bandwidth=12.5] with the middle value for the number of spectral
channels available [nchan=’medium’] and with 9-level sampling [spect.levels=9]. Each spectral window will be centered on
the rest frequencies of the lines at 9816.867, 9487.824, 9173.323, and 8872.571 MHz [restfreq= 9816.867, 9487.824,
9173.323, 8872.571]. We wish the cycle time to go through a full switching cycle to be 1 second [swper=1.0]. We want the
Spectrometer to record data every 30 seconds [tint=30]. We wish to Doppler track the spectral line in the commonly used
Local Standard of Rest velocity frame [vframe=’lsrk’; vdef=’Radio’]. We would like to use the low-power noise-diode
[noisecal=’lo’]. Finally, we wish to take the data using the circular polarizations, R and L [pol=’Circular’].
46 CHAPTER 5. INTRODUCTION TO SCHEDULING BLOCKS AND OBSERVING SCRIPTS
Multiple Spectral Lines, Multi-beam Nodding Observations
# configuration definition for spectral line observations
# using a multi−beam receiver for nodding observations
spectralnodconfig = ”””
receiver = ’Rcvr22_26’
beam = ’B34’
obstype = ’Spectroscopy’
backend = ’Spectrometer’
nwin = 4
restfreq = 23694.495 , 23722.633 , 23870.129 , 25056.025
deltafreq = 0 ,0 ,0 , 0
bandwidth = 50
swmode = ’tp’
swtype = ’none’
swper = 1.0
tint = 30
vlow = 0
vhigh = 0
vframe = ’lsrk’
vdef = ’Radio’
noisecal = ’lo’
pol = ’Circular’
nchan = ’low’
spect.levels = 3
”””
The fourth and final example configuration has the name “spectral nod config” and can be used for spectral line
observations [obstype=’Spectroscopy’] using nodding observations [swmode=’tp’; swtype=’none’] with the upper half of
the multi-beam K–band (22 to 26 GHz, beams 3 and 4) receiver [receiver=’Rcvr22 26’; beam=’B34’] and the Spectrometer
as the backend detector without cross-polarization products [backend=’ Spectrometer’]. We wish to take data on multiple
spectral lines [nwin=4], each having a 50 MHz bandwidth [bandwidth=50] with the lowest value for the number of spectral
channels [nchan=’low’] and with 3-level sampling [spect.levels=3]. Each spectral window will be centered on the rest
frequencies of the lines at 23694.495, 23722.633, 23870.129, and 25056.025 MHz [restfreq=23694.495, 23722.633,
23870.129, 25056.025]. We wish the cycle time to go through a full total power switching cycle to be 1 second [swper=1.0].
We want the Spectrometer to record data every 30 seconds [tint=30]. We wish to Doppler track the spectral line in the
commonly used Local Standard of Rest velocity frame [vframe=’lsrk’; vdef=’Radio’]. We would like to use the low-poer
noise-diode [noisecal=’lo’]. Finally, we wish to take the data using the circular polarizations, R and L [pol=’Circular’].