Antenna gain effects

The main python script for to simulate visibility data observed by SKA observations in the presence of any of a number of physical effects afflicting the antenna gain is mid_simulation.py.

mid_simulation

Simulate SKA-MID direction dependent errors

usage: mid_simulation.py [-h] [--rmax RMAX] [--image_sampling IMAGE_SAMPLING]
                         [--configuration CONFIGURATION]
                         [--antennas [ANTENNAS ...]] [--source SOURCE]
                         [--ra RA] [--declination DECLINATION] [--band BAND]
                         [--nchan NCHAN] [--channel_width CHANNEL_WIDTH]
                         [--integration_time INTEGRATION_TIME]
                         [--time_range TIME_RANGE TIME_RANGE]
                         [--time_step TIME_STEP] [--make_images MAKE_IMAGES]
                         [--only_actual ONLY_ACTUAL] [--apply_pb APPLY_PB]
                         [--pbtype PBTYPE] [--seed SEED]
                         [--flux_limit FLUX_LIMIT] [--npixel NPIXEL]
                         [--cellsize CELLSIZE] [--weighting WEIGHTING]
                         [--robustness ROBUSTNESS] [--results RESULTS]
                         [--elevation_sampling ELEVATION_SAMPLING] [--r0 R0]
                         [--height HEIGHT] [--screen SCREEN]
                         [--isoplanatic ISOPLANATIC] [--time_chunk TIME_CHUNK]
                         [--channel_start CHANNEL_START] [--mode MODE]
                         [--duration DURATION]
                         [--wind_conditions WIND_CONDITIONS]
                         [--global_pe GLOBAL_PE GLOBAL_PE]
                         [--static_pe STATIC_PE STATIC_PE]
                         [--dynamic_pe DYNAMIC_PE]
                         [--pointing_directory POINTING_DIRECTORY]
                         [--vp_directory VP_DIRECTORY]
                         [--vp_support VP_SUPPORT] [--use_dask USE_DASK]
                         [--write_gt WRITE_GT] [--write_pt WRITE_PT]
                         [--imaging_dft_kernel IMAGING_DFT_KERNEL]
                         [--add_noise ADD_NOISE] [--ra_s RA_S] [--dec_s DEC_S]
                         [--vp_real_file VP_REAL_FILE]
                         [--vp_imag_file VP_IMAG_FILE] [--obs_time OBS_TIME]

Named Arguments

--rmax

Maximum distance of dish from centre (m)

Default: 200000.0

--image_sampling

Number of points per synthesized beam

Default: 3.0

--configuration

MID Configuration: MID | MEERKAT+

Default: 'MID'

--antennas

Antenna names to include (default is all)

--source

Type of source: s3sky or point or double

Default: 's3sky'

--ra

Right ascension of phase centre (degrees)

Default: 0.0

--declination

Declination of phase centre (degrees)

Default: -40.0

--band

Band B1LOW | B1 | B2 | B5 | Ku

Default: 'B2'

--nchan

Number of frequency channels

Default: 1

--channel_width

Channel bandwidth (Hz) (default is to calculate from band frequency)

--integration_time

Integration time (s)

Default: 180

--time_range

Time range in hour angle

Default: [-4.0, 4.0]

--time_step

Time step (unit: second of time)

--make_images

Make the images?

Default: 'False'

--only_actual

Only make the actual data?

Default: 'False'

--apply_pb

Apply the primary beam in modes troposphere and ionosphere?

Default: 'True'

--pbtype

Primary beam model: MID_B1 MID_B1LOW MID_B2 MID_Ku MEERKAT_B1 MEERKAT_B2 MEERKAT_Ku

Default: 'MID_B2'

--seed

Random number seed

Default: 18051955

--flux_limit

Lower flux limit (Jy)

Default: 0.01

--npixel

Number of pixels in the resulting image

Default: 512

--cellsize

Cellsize in radians (will calculate if set to None)

--weighting

Type of weighting (natural, uniform or robust)

Default: 'uniform'

--robustness

Robustness for robust weighting

Default: 0.0

--results

Directory for results

Default: './'

--elevation_sampling

Sampling in elevation for surface (deg)

Default: 1.0

--r0

R0 (meters)

Default: 5000.0

--height

Height of layer (meters)

Default: 300000.0

--screen

Location of atmospheric phase screen data

Default: rascil.processing_components.parameters.rascil_data_path

--isoplanatic

Are the phase screens to be treated as isoplanatic?

Default: 'False'

--time_chunk

Time for a chunk (s)

Default: 3600.0

--channel_start

First channel of interest if interested in some frequency range. Use with –nchan

--mode

Mode of simulation: wind_pointing|random_pointing|polarisation|ionosphere|troposphere|heterogeneous|surface

Default: 'none'

--duration

Type of duration: long or medium or short. Set to custom when using options –integration_time and –time_range (or–time_step)

Default: 'long'

--wind_conditions

SKA definition of wind conditions: precision, standard or degraded

Default: 'precision'

--global_pe

Global pointing error (absolute values)

Default: [0.0, 0.0]

--static_pe

Multipliers for static errors

Default: [0.0, 0.0]

--dynamic_pe

Multiplier for dynamic errors

Default: 1.0

--pointing_directory

Location of wind PSD pointing files

Default: rascil.processing_components.parameters.rascil_data_path

--vp_directory

Location of voltage pattern files

--vp_support

Number of pixels in voltage pattern images

--use_dask

Use dask processing?

Default: 'True'

--write_gt

Write gaintable files as HDF

Default: 'False'

--write_pt

Write pointing table files as HDF

Default: 'False'

--imaging_dft_kernel

DFT kernel: cpu_looped | cpu_numba | gpu_raw

--add_noise

Add noises to visibilities

Default: 'False'

--ra_s

Right ascension of phase centre (degrees)

Default: -999.99

--dec_s

Declination of phase centre (degrees)

Default: 999.99

--vp_real_file

Voltage pattern real part file name

--vp_imag_file

Voltage pattern imagine part file name

--obs_time

Observation start time