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CHIME/FRB Baseband Analysis

Analysis routines for triggered baseband recording system

Overview

baseband-analysis hosts the analysis routines needed for processing baseband data of the CHIME FRB Science Collaboration. The automated baseband pipeline integrates these routines into a sequential process run on the frb-analysis cluster.

Installation

Installing some of the dependencies (especially ch_utils) is nontrivial. We suggest to use the docker container running the code. Detailed instructions can be found in the wiki.

Dependancies not available in PyPi

Pipeline

baseband_pipeline

Data

Raw CHIME baseband data can be found in the frb-baseband (~post-March 2019 event) archiver and can be located based on the date and event number. Raw data can be found in the raw sub-directory of the event and with each file .h5 file consisting of the raw complex voltage timestream of 1024 dual linear feeds. The data is pre-processed into frequency channels with the suffix number of the file indicating the frequency channel ID (i.e. 0=400 MHz, 1023=800 MHz).

This raw data is processed by the pipeline with output processed data products being stored in the processed sub-directory. Most users will interact with this processed data and not the raw data itself.

Routines

The basic steps of the pipeline, summarized in the schematic above, consist three stages:

  • Refinement

-refines DM (optimizes S/N) -time of burst -RFI mask

  • Localization

  • Fits beammodel to tiedbeam grid

  • Outputs single-beam beamformed baseband data for scientific analysis.

  • Science Pipelines (e.g. Polarization, Burst Morphology, etc.)

  • Input: Single-beam beamformed baseband data; formatted as (nchan,npol=2,nsamp)

  • Descriptions of science pipelines to come...