Directory structure

This package is agnostic to the arrangement of model data; it simply fetches and processes URLs. Here we document the directory structure adopted for the MeerKAT telescope, both as a suggestion for other telescopes and for users who wish to explore the available models.

Models are arranged in three levels, connected by alias files:

1. The models themselves are stored as model_type/fixed/sha256_hash.h5, where model_type is the value stored in the HDF5 model_type attribute.

2. For each configuration of each target (see Concepts), the current model is pointed to by model_type/config/target/config.alias.

3. For each target, the alias for the current configuration is pointed to by model_type/current/target.alias.

The target may contain multiple components separated by slashes. It may also be empty for telescope-level models, in which case the level 2 alias becomes model_type/config/config.alias and the level 3 alias becomes model_type/current.alias. The config is intended to be a flat version string for the configuration. See Telescope state integration for an example of how these aliases point to each other.

Below, we list the naming conventions currently in use for MeerKAT for target and config. Other telescopes will likely use a different configuration management system and need to describe a different range of targets, so are not expected to use the same naming conventions.

RFI mask

target

None

config

meerkat

Band mask

target

band/nb_ratio=ratio, where band is the single-letter abbreviation for the receiver band (l, s, u or x in MeerKAT) and ratio is the integer ratio between the digitised bandwidth and the output correlator bandwidth. It is 1 for a wideband instrument and larger for narrowband instruments.

config

The document number of the release note for the correlator.