FIP-TOI: Fast Imaging Pipeline for Pulsar Localisation with a Transient-Oriented Radio Astronomical Imager

Abstract: Rapid localisation of celestial transients like pulsars requires efficient short-timescale imaging. In radio astronomy, Fast Imaging Pipeline (FIP) addresses this need by reconstructing radio astronomical images and identifying candidates statistically. The FIP comprises imaging and localisation components but conventional radio astronomical imagers, optimised for longer integrations, limit its efficiency. To overcome this limitation, a Transient-Oriented Imager (TOI) is developed based on Singular Value Decomposition (SVD) and parallelised on NVIDIA GPUs using CUDA. Integrating the TOI with an advanced transient detector, FITrig, forms the FIP-TOI enabling real-time and high-precision localisation of pulsar candidates. For 4K x 4K-pixel images, FIP-TOI accelerates localisation by roughly tenfold compared to a pipeline using the standard imager WSClean. Testing on diverse datasets -- including fields with multiple pulsars, an on-and-off pulsar, and a pulsar exhibiting intensity changes -- FIP-TOI demonstrates robust performance across all scenarios.