What is a reading profile?

A reading profile is the combination of two things that together tell DASexplorer how to load and display data from a specific acquisition system:

1. A reader function — a Python function that knows how to open a particular file format and return a standardised DASDataset object.
2. A profile entry in config.json — a block of configuration that links the profile to its reader function and defines the default visualisation parameters (colour scale, frequency range, F-K filter settings, RGB bands, etc.).

Together they make DASexplorer interrogator-agnostic: adding support for a new system is a matter of writing a reader and registering a profile, without changing the rest of the application.

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The reader function

The reader function handles everything that is specific to one file format and one acquisition system: opening the file, extracting the raw data array, converting it to physical units, reading the sampling frequency and channel distances, and parsing the UTC timestamp. It accepts a standard set of arguments:

def my_reader(
    path: str,
    stride: Optional[int] = None,         # channel decimation factor
    read_dmin_m: Optional[float] = None,  # spatial crop start [m]
    read_dmax_m: Optional[float] = None,  # spatial crop end [m]
    **kwargs,                             # format-specific extras
) -> DASDataset:

It always returns a DASDataset — a standardised container that the rest of the application (waterfall display, annotation tools, analysis dialogs, export functions) consumes without needing to know anything about the original file format.

Format-specific parameters that not all readers share — such as num_files for HDAS 2.5 or selected_channels_m for OptaSense — are passed through **kwargs and documented in the reader's docstring.

Reader functions live in core/readers_lib/, one file per interrogator family (e.g. hdas.py, optasense.py, idas.py). They are imported and registered in core/readers.py via the READERS dictionary.

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The profile entry

The profile entry in config.json has two roles:

1. Linking to the reader — the "reader" field identifies which function to call when a file is loaded with this profile:

"reader": "my_reader"

This must match a key in the READERS dictionary exactly.

2. Default visualisation parameters — everything else in the profile defines how the data looks when first loaded: colour scale limits, bandpass filter range, F-K velocity bounds, RGB frequency bands, and so on. The user can change any of these interactively from the left panel; the profile values are just the starting point.

"myreader_v1": {
    "label": "MyInterrogator (.ext) Description",
    "reader": "my_reader",
    "file_extensions": [".ext"],
    "vmin": 0.0,
    "vmax": 0.5,
    "fmin_hz": 1.0,
    ...
}

Profiles are managed from Settings → Configuration Profiles in the GUI, or by editing config.json directly.

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Summary

Component	Where it lives	What it does
Reader function	core/readers_lib/<name>.py	Opens the file, returns DASDataset
Reader registration	core/readers.py (READERS dict)	Maps the reader key to the function
Profile entry	cfg/config.json	Links the key to default display settings

To add a new interrogator, see Adding a reading profile.