FLITS

Fast-Look Interactive Transient Suite.

FLITS is browser-based FRB analysis software for interactive burst inspection, masking, measurement, DM optimization, temporal/spectral diagnostics, and export. It reads SIGPROC filterbank (.fil), PSRFITS search/fold data (.fits, .sf), and CHIME/FRB HDF5 (.h5, .hdf5) including public catalog waterfalls and beamformed BBData tiedbeam_power files. The I/O layer is pluggable — third parties can register custom formats via importlib entry points without forking.

The selected analysis state is recorded in a JSON session snapshot. Given the snapshot and original data, flits replay restores the selections and recomputes supported measurements without a browser.

The guided GBT workflow walks through the selections and results shown in the interface.

Why FLITS exists

Measuring a detected burst involves selecting an event window and noise reference, masking interference, choosing a frequency range, and refining the dispersion measure (DM). These choices affect the resulting measurements and must be preserved to interpret and reproduce them.

FLITS was built for a repeater campaign spanning GBT at L and P band, Nançay, Westerbork, Onsala, Stockert, and CHIME. A common reader interface and configurable telescope presets support analysis across their formats and calibration conventions. The session retains the selected state so collaborators can reopen it and recompute supported measurements from the original data.

FLITS builds on specialist search, data-processing, and analysis packages. It connects measurements through a shared session model with explicit calibration and uncertainty metadata. Flux and fluence estimates without a supplied SEFD uncertainty are flagged as having an incomplete uncertainty budget.

FLITS is not a search pipeline — it starts from a burst you already have.

Quick Start

Install the published package:

pip install flits
flits --data-dir /path/to/filterbanks --host 127.0.0.1 --port 8123

Then open http://127.0.0.1:8123.

Optional model fitting uses fitburst, which is intentionally left out of the PyPI dependency metadata because package indexes reject direct URL runtime dependencies. To enable model fitting after installing FLITS:

pip install "fitburst @ https://github.com/CHIMEFRB/fitburst/archive/3c76da8f9e3ec7bc21951ce1b4a26a0255096b69.tar.gz"

Highlights

• Browser-based workflow for burst inspection on SIGPROC, PSRFITS, and CHIME/FRB HDF5 data.
• CHIME support includes public catalog waterfalls and beamformed BBData power products.
• Interactive crop, event, off-pulse, spectral-window, and masking controls.
• Automatic burst localization in time and frequency (matched-filter event window, spectral extent, and off-pulse placement in one click).
• Calibrated fluence and peak-flux outputs when an SEFD is available.
• DM optimization using integrated-event S/N and DMphase.
• Temporal-structure, PSD, ACF, and optional selected-event model fitting.
• Sub-burst drift rate in MHz/ms from the mask-corrected 2D autocorrelation, cross-checked against a component-centroid regression, with the drift/DM degeneracy reported as the DM offset that would account for the measured slope.
• Weighted Q/U RM synthesis with optional RM-CLEAN, significance and quality diagnostics, and JSON/CSV products — measured in-session from a full-Stokes burst file, or from an externally prepared Q/U spectrum.
• Export bundles and JSON session snapshots for reproducible analysis.

Documentation

• Full docs: dirkkuiper.github.io/flits
• Getting started: Quickstart
• Guided example: GBT Burst Workflow
• Installation and deployment: Installation
• Developer testing: Testing
• Developer publishing: Publishing

The docs cover Python installs, Docker, Apptainer, remote/HPC use, interactive workflow guidance, measurements, DM optimization, temporal/spectral analysis, sub-burst drift, exports, and release procedures.

Release Channels

• PyPI and ghcr.io/dirkkuiper/flits:latest track stable releases.
• ghcr.io/dirkkuiper/flits:<version> pins an exact release.
• ghcr.io/dirkkuiper/flits:edge tracks the current main branch for snapshot testing.

Citation

If you use FLITS in research, cite the software and link to the repository:

• PyPI package: flits
• Repository: https://github.com/DirkKuiper/flits
• Citation metadata: CITATION.cff

License

FLITS is released under the GNU GPLv3. See LICENSE.

The interface bundles plotly.js (MIT) so it works without fetching anything from a CDN; its licence travels with the copy in flits/web_static/vendor/.