pyuvdata

pyuvdata defines a pythonic interface to interferometric data sets. Currently pyuvdata supports reading and writing of miriad and uvfits files and reading of FHD (Fast Holographic Deconvolution) visibility save files.

Motivation

The three main goals are:

  1. To provide a high quality, well documented path to convert between data formats
  2. Support the direct use of datasets from python with minimal software
  3. Provide precise data definition via both human readable code and high quality online documentation

Package Details

Tested File Paths

  • uvfits -> miriad (aipy)
  • miriad (aipy) -> uvfits
  • FHD -> uvfits
  • FHD -> miriad

File standards

  • miriad is supported for aipy-style analysis, further testing is required for use in the miriad package
  • uvfits conforms to AIPS memo 117 (as of May 2015). It is tested against FHD, CASA, and AIPS. However AIPS is limited to <80 antennas and CASA imaging does not seem to support >255 antennas.
  • FHD (read-only support, tested against MWA and PAPER data)

Known Issues and Planned Improvements

  • different multiple spectral windows or multiple sources are not currently supported
  • testing against miriad package
  • replacing AIPY and pyephem with astropy+NOVAS for time and phase calculations
  • support for direct reading and writing of Measurement Sets For details see the issue log. Contributions are welcome!

History

pyuvdata was originally developed in the low frequency 21cm community to support the development of calibration and foreground subtraction pipelines. Particular focus has been paid to supporting drift and phased array modes.

Installation

Dependencies

First install dependencies. The numpy and astropy versions are important, so be sure to make sure these are up to date before you install. * numpy >= 1.10 * scipy * astropy >= 1.2 * pyephem * pyfits * aipy

Install pyuvdata

Download the latest release here github.com/HERA-Team/pyuvdata/release1.0

Navigate into the directory and run python setup.py install Note that this will automatically install all dependencies. If you use anaconda or another package manager you might prefer to do not do this.

To install without dependencies, run python setup.py install --no-dependencies

Tests

Requires installation of nose package. From the source pyuvdata directory run nosetests.

API

The primary interface to data from python is via the UVData object. It provides import and export functionality to all supported file formats (UVFITS, Miriad, FHD) and can be interacted with directly. The attributes of the UVData object are described in the parameters description.

Further Documentation