OSKAR_workflow

A nextflow pipline for running OSKAR simulations with different telescope models, sky models, and various other parameters like pointing and errors, followed by calibration with Hyperdrive.

Warning

Due to the resource limitations of the machine I'm running this on, I have implemented only a serial pipeline. i.e. For a set of observing parameters, OSKAR will be run first then Hyperdrive then WSCLEAN. Only once the first set is of parameters is done, the next set can begin.

Installation

You will need to install nextflow to run this script.

Usage

First, clone this project and enter it. All settings can be found in the nextflow.config file. Comments are in there to help the user understand what each option does.

Warning

Nextflow is a great tool, once it works. It is very picky about syntax, and the errors produced by nextflow are not informative at all. Make sure you check for syntax problems!

Important Settings

Define what processes you want to run in the first params block:

params {
    // What do you want to run?
    run_beam_sim = <true|false>
    run_int_sim = <true|false>
    run_hyperdrive = <true|false>
    run_wsclean = <true|false>

    ...
}

Define what sky models you want to simulate:

params.sky_models = [ "/path/to/sky_model.osm",
    "/path/to/another_sky_model.osm",
]

Define telescope models you want to use (note there is no / at the end of the paths):

params.telescope_models = [ "/path/to/telescope_model",
    "/path/to/another_tm",
]

Define pointings you want to use:

params.pointings = [
    [ name: 'EoR0', 
        ra: 0.0, 
        dec: -27.0, 
        start_time_utc: '2000-01-01 00:00:00.0',
        x_gain: 0.0,
        y_gain: 0.0,
        x_gain_error_time: 0.0,
        y_gain_error_time: 0.0,
    ],
    [ name: 'LST_5.2', 
        ra: 78.0, 
        dec: -30.0, 
        start_time_utc: '2000-01-01 00:00:00.0',
        x_gain: 0.0,
        y_gain: 0.0,
        x_gain_error_time: 1.0,
        y_gain_error_time: 1.0,
    ],
]

Define beam simulation settings:

params.beam_settings = [ 
    General: [ app: 'oskar_sim_beam_pattern' ], // Do not change this
    beam_pattern: [
        'beam_image/fov_deg':180.0,
        'station_outputs/fits_image/amp':true,
        'root_path': null,
        // Add other options here if you need
    ]
]

Define interferometer simulation settings:

params.interferometer_settings = [
    General: [ app: 'oskar_sim_interferometer' ], // Do not change this
    interferometer: [
        ms_filename: null, // This will be set dynamically by the process
        channel_bandwidth_hz: 1e6,
        time_average_sec: 1.0
        // Add other options here if you need
    ]
]

Define global/base OSKAR settings that will be used throughout all runs:

params.oskar_settings = [
    General: [
        version: "2.11.0"
    ],
    simulator: [
        use_gpus: true,
        double_precision: true,
    ],
    sky: [
        'oskar_sky_model/file': null // This will be set dynamically by the process
    ],
    observation: [
        start_frequency_hz: 100e6,
        num_channels: 3,
        frequency_inc_hz: 1e6,
        phase_centre_ra_deg: 20.0,
        phase_centre_dec_deg: -30.0,
        num_time_steps: 10,
        length: '02:00:00.0'
    ],
    telescope: [
        input_directory: null // This will be set dynamically by the process
    ],
]

Define Hyperdrive settings (you are not able to add more than these):

params.hyperdrive_settings = [
    veto_threshold: 0.01,
    source_dist_cutoff: 5,
    source_list: '/path/to/srclist',
]

Running

To execute the workflow after preparing the settings, simply run:

nextflow run main.nf