Crate birli

Birli is a library of common preprocessing tasks performed in the data pipeline of the Murchison Widefield Array (MWA) Telescope.

Examples

Here’s an example of how to flag some visibility files

use birli::{
    context_to_jones_array, flag_jones_array_existing, write_flags,
    cxx_aoflagger_new, get_flaggable_timesteps, init_flag_array,
    get_antenna_flags, mwalib,
};
use mwalib::CorrelatorContext;
use tempfile::tempdir;

// define our input files
let metafits_path = "tests/data/1297526432_mwax/1297526432.metafits";
let gpufits_paths = vec![
    "tests/data/1297526432_mwax/1297526432_20210216160014_ch117_000.fits",
    "tests/data/1297526432_mwax/1297526432_20210216160014_ch117_001.fits",
    "tests/data/1297526432_mwax/1297526432_20210216160014_ch118_000.fits",
    "tests/data/1297526432_mwax/1297526432_20210216160014_ch118_001.fits",
];

// define a temporary directory for output files
let tmp_dir = tempdir().unwrap();

// define our output flag file template
let flag_template = tmp_dir.path().join("Flagfile%%%.mwaf");

// Create an mwalib::CorrelatorContext for accessing visibilities.
let context = CorrelatorContext::new(&metafits_path, &gpufits_paths).unwrap();

// create a CxxAOFlagger object to perform AOFlagger operations
let aoflagger = unsafe { cxx_aoflagger_new() };

// Determine which timesteps and coarse channels we want to use
let img_coarse_chan_idxs = &context.common_coarse_chan_indices;
let img_timestep_idxs = get_flaggable_timesteps(&context).unwrap();

let img_timestep_range =
    *img_timestep_idxs.first().unwrap()..(*img_timestep_idxs.last().unwrap() + 1);
let img_coarse_chan_range =
    *img_coarse_chan_idxs.first().unwrap()..(*img_coarse_chan_idxs.last().unwrap() + 1);

// Prepare our flagmasks with known bad antennae
let flag_array = init_flag_array(
    &context,
    &img_timestep_range,
    &img_coarse_chan_range,
    Some(get_antenna_flags(&context)),
);

// load visibilities into our array of jones matrices
let (mut jones_array, flag_array) = context_to_jones_array(
    &context,
    &img_timestep_range,
    &img_coarse_chan_range,
    Some(flag_array),
);

// use the default strategy file location for MWA
let strategy_filename = &aoflagger.FindStrategyFileMWA();

// run the strategy on the imagesets, and get the resulting flagmasks for each baseline
let flag_array = flag_jones_array_existing(
    &aoflagger,
    &strategy_filename,
    &jones_array,
    Some(flag_array),
    true,
);

// write the flags to disk as .mwaf
write_flags(&context, &flag_array, flag_template.to_str().unwrap(), &img_coarse_chan_range).unwrap();

Details

Birli reads visibilities with MWALib and uses CXX to bind to the AOFlagger C++ library. For more details about AOFlagger’s interface, check out the aoflagger::AOFlagger documentation

Re-exports

pub use io::mwaf::FlagFileSet;

pub use io::uvfits::UvfitsWriter;

pub use corrections::correct_cable_lengths;

pub use corrections::correct_geometry;

pub use flags::flag_jones_array_existing;

pub use flags::flagmask_or;

pub use flags::get_antenna_flags;

pub use flags::get_flaggable_timesteps;

pub use flags::init_flag_array;

pub use flags::write_flags;

pub use mwa_rust_core;

pub use mwa_rust_core::mwalib;

pub use mwalib::fitsio;

pub use mwalib::fitsio_sys;

Modules

corrections

Corrections that can be performed on visibility data

error

Errors that can occur in Birli

flags

Methods for manipulating flagmasks and flagging imagesets

io

Input and Ouput data file format modules

Structs

Complex

A complex number in Cartesian form.

CxxAOFlagger

CXX Wrapper for aoflagger::AOFlagger, the main class for access to the flagger functionality.

CxxFlagMask

CXX Wrapper for aoflagger::FlagMask, a two-dimensional mask of bool flags.

CxxImageSet

CXX Wrapper for aoflagger::ImageSet, a set of time-frequency ‘images’ which together contain data for one correlated baseline.

CxxStrategy

CXX Wrapper for aoflagger::Strategy, a flagging strategy definition.

Jones

Functions

context_to_jones_array

generate a 3 dimensional array of Jones matrices from an observation’s mwalib::CorrelatorContext, for all baselines, over a given range of mwalib timestep and coarse channel indices.

cxx_aoflagger_new^⚠

Create a new CxxAOFlagger instance

flag_baseline_view_to_flagmask

Create an aoflagger CxxFlagMask for a from the given flag array view

get_aoflagger_version_string

Get the version of the AOFlagger library from the library itself.

init_baseline_imgsets

Initialize a vector of length [num_baselines] containing CxxImageSet of dimensions [width] and [height],

jones_baseline_view_to_imageset

Create an aoflagger CxxImageSet for a particular baseline from the given jones array