stimela-ska1mid-sim.py

# import stimela package
import stimela

# Recipe I/O configuration
INPUT = "input-ska1mid" # This folder must exist
OUTPUT = "output-ska1mid"
MSDIR = "msdir-ska1mid"
PREFIX = "ska1mid-example"  # Prefix for output images

# MS name
MS = 'ska1mid_simulation_example.ms'

# Use the NVSS skymodel. This is natively available
LSM = 'ska1mid-skymodel.txt'


# Start stimela Recipe instance
pipeline = stimela.Recipe("SKA1MID Simulation Example",     # Recipe name
                  ms_dir=MSDIR)             # Folder in which to find MSs

 # 1: Make empty MS 
pipeline.add("cab/simms",           # This is the module/cab that creates an empty visibility set     
             "simms_example",       # prefix (alpha-numeric) for name of docker container that will be created to run this cab
             {
                # dictionary of options to be parsed to cab
                "msname"    :   MS,    
                "telescope" :   'ska1mid197',                  # Telescope name
                "direction" :   'J2000,0deg,-30deg',        # Phase tracking centre of observation
                "synthesis" :   0.125,                      # Synthesis time of observation
                "dtime"     :   4,                          # Integration time in seconds
                "freq0"     :   '750MHz',                   # Start frequency of observation
                "dfreq"     :   '1MHz',                     # Channel width
                "nchan"     :   1,                          # Number of channels 
             },    
             input=INPUT,           # Folder where the cab expects to find input files
             output=OUTPUT,         # Folder where outputs and logs will be place
             label='Creating MS')   # Label for this task (optional)

# 2: Simulate visibilities into it
pipeline.add('cab/simulator', 
             'simulator_example',
             {
                "msname"    :   MS, 
                "skymodel"  :   LSM,                    # Sky model to simulate into MS
                "addnoise"  :   True,                   # Add thermal noise to visibilities
                "column"    :   'CORRECTED_DATA',
                "sefd"      :   831,                    # Compute noise from this SEFD
                "recenter"  :   True,                   # Recentre sky model to phase tracking centre of MS
             },
              input=INPUT, 
              output=OUTPUT,
              label='Simulating visibilities')


## 3: Image

pipeline.add('cab/wsclean',
             'imager_example',
             {
                 "msname"   :   MS,
                 "weight"   :   'briggs -2',             # uv-weighting
                 "name"     :   PREFIX,                 # prefix for output images
                 "npix"     :   3000,                   # image size in pixels
                 "cellsize" :   0.2,                      # pixel size in arcsec
                 "niter"    :   1000,                   # number of clean iterations
                 "mgain"    :   0.9,                    # 1 - major loop gain
             },
             input=INPUT,
             output=OUTPUT,
             label='Imaging MS')

# Run recipe. The 'steps' added above will be executed in the sequence that they were adde. The 'steps' added above will be
# executed in the sequence that they were added
pipeline.run()

The sky model file (ska1mid-skymodel.txt) is at https://gist.github.com/SpheMakh/28e86fa813711ff1a430b1aa1ed55b06