orca.transform.imaging
Image generation transforms using WSClean.
Provides functions for creating dirty images, movies from FITS sequences, integrated images, and Stokes I/V imaging from measurement sets. Uses WSClean for imaging and supports multi-frequency synthesis.
Attributes
Functions
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Create an MP4 movie from a sequence of FITS images. |
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Create an integrated image from multiple measurement sets. |
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Make dirty image from a list of measurement sets using WSClean. |
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Reproject one fits image to wcs of another. |
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Stacks images in fits_list and writes to output_path. |
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Generate Stokes I and V images from calibrated measurement sets. |
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Co-add multiple FITS images by averaging. |
Module Contents
- orca.transform.imaging.make_movie_from_fits(fits_tuple: Tuple[str], output_dir: str, scale: float, output_filename: str | None = None) str[source]
Create an MP4 movie from a sequence of FITS images.
Uses matplotlib to render each frame and ffmpeg to encode the movie.
- Parameters:
fits_tuple – Ordered sequence of paths to FITS image files.
output_dir – Directory to save the output movie.
scale – Symmetric color scale for image display (-scale to +scale).
output_filename – Optional output filename. Defaults to input basename + .mp4.
- Returns:
Path to the generated movie file.
- orca.transform.imaging.integrated_image(msl: List[str])[source]
Create an integrated image from multiple measurement sets.
- Parameters:
msl – List of measurement set paths.
Note
Not yet implemented.
- orca.transform.imaging.make_dirty_image(ms_list: List[str], output_dir: str, output_prefix: str, make_psf: bool = False, briggs: float = 0, inner_tukey: int | None = None, n_thread: int = 10, more_args: List[str] | None = None) str | Tuple[str, str][source]
Make dirty image from a list of measurement sets using WSClean.
Creates a dirty (non-deconvolved) image with specified weighting scheme. Optionally generates the PSF image as well.
- Parameters:
ms_list – List of measurement set paths to image.
output_dir – Directory for output images.
output_prefix – Prefix for output filenames.
make_psf – If True, also generate the PSF image at 2x size.
briggs – Briggs robust weighting parameter (-2 to 2).
inner_tukey – Inner Tukey taper width in wavelengths.
n_thread – Number of threads for WSClean.
more_args – Additional WSClean arguments.
- Returns:
If make_psf is True, tuple of (image_path, psf_path). Otherwise, just the image path.
- orca.transform.imaging.reproject_fits(fits_path1: str, fits_path2: str, output_path: str | None = None) str | numpy.ndarray[source]
Reproject one fits image to wcs of another.
- Parameters:
fits_path1 – fits file of reference image
fits_path2 – fits file to be reprojected
output_path – output for reprojected fits image (optional)
- Returns:
path to reprojected fits image if output_path is not None, else the numpy array of the reprojected image.
- orca.transform.imaging.stack_images(fits_list: List[str], output_path: str)[source]
Stacks images in fits_list and writes to output_path.
- Parameters:
fits_list – list of fits files to be stacked
output_path – output path (including name)
- orca.transform.imaging.stokes_IV_imaging(spw_list: List[str], start_time: datetime.datetime, end_time: datetime.datetime, source_dir: str, work_dir: str, scratch_dir: str, phase_center: astropy.coordinates.SkyCoord | None = None, taper_inner_tukey: int = 30, make_snapshots: bool = False, keep_scratch_dir: bool = False, partitioned_by_hour: bool = True)[source]
Generate Stokes I and V images from calibrated measurement sets.
Celery task that applies calibration, flags, integrates across spectral windows, and produces Stokes I/V images. Can optionally generate snapshot images for each timestep.
- Parameters:
spw_list – List of spectral window identifiers.
start_time – Start of the observation time range.
end_time – End of the observation time range.
source_dir – Directory containing source measurement sets.
work_dir – Working directory for intermediate products.
scratch_dir – Scratch directory for temporary files.
phase_center – Optional phase center for imaging. Defaults to zenith.
taper_inner_tukey – Inner Tukey taper width in wavelengths.
make_snapshots – If True, produce per-timestep snapshot images.
keep_scratch_dir – If True, don’t delete temporary directory.
partitioned_by_hour – Whether data is partitioned by hour.
- Returns:
None. Writes output images to work_dir.
- orca.transform.imaging.coadd_fits(fits_list: List[str], output_path: str) str | None[source]
Co-add multiple FITS images by averaging.
Computes the mean of all input images pixel-by-pixel. Header is taken from the first image.
- Parameters:
fits_list – List of paths to FITS images to co-add.
output_path – Output path for the averaged image.
- Returns:
Output path on success, None if fewer than 2 images provided.