LOBEs

EveryBeam provides experimental support for the LOBEs beam model as an alternative to the Hamaker model for LOFAR observations. Currently, LOBEs is supported for the following LOFAR LBA stations:

• The superterp LBA core stations (CS002LBA - CS007LBA)

• Core station CS302LBA (at low frequency resolution)

• International LBA station SE607LBA

Note

To download and install the LOBEs coefficient files when building EveryBeam, please set the flag -DDOWNLOAD_LOBES=On, see also the Build instructions. To avoid redundant downloads of the large coefficient files, the value of this flag is Off by default. The downloaded coefficient files are stored in CMAKE_INSTALL_PREFIX/share/everybeam/lobes upon installation, with each available LOFAR station having its unique coefficient file.

Note

The coefficients of the LOBEs model are quite large, up to 1GB in total. As a consequence, the Docker image that is pushed to the image registry and used for creating the Debian package does not include the LOBEs coefficients.

Fitting LOBEs coefficients

EveryBeam contains a script to fit (Legendre polynomial) coefficients to simulated results, see scripts/coeff_scripts/convert_lobes.py. This script either takes one HDF5 file containing station coordinates and simulated result for all available frequencies, or a list of MATLAB files with simulated results per frequency. In the latter case, station coordinates can be read from a separate MATLAB file or extracted using lofarantpos). The order of the Legendre polynomial fit can be controlled by the user.

Using the LOBEs model

For a python demo on how to use the LOBEs model, please consult LOFAR telescope: assessing the LOBEs model.

Note

EveryBeam falls back to the Hamaker model after spawning a warning for stations that have no corresponding LOBEs coefficient file. The search path for the LOBEs coefficient files is CMAKE_INSTALL_PREFIX/share/everybeam/lobes by default, but can be overridden via the Options.coeff_path field.