A Python/CuPy Software Correlator for QUEST: Real-Time Performance and Initial Imaging
Abstract
We present a Python/CuPy FX software correlator for small radio interferometer arrays and evaluate it on QUEST (Qilu University Explorer Survey Telescope). The system combines multi-threaded data ingest, pinned-memory host-device transfers, GPU-accelerated correlation, Polyphase Filter Bank channelization, MAD-based RFI flagging, and delay/phase calibration in a single workflow aimed at array commissioning. On a single NVIDIA RTX 4090D GPU, the implementation reaches a peak throughput of 1.51 GB/s, which is sufficient for real-time operation in the four-antenna mode tested here. After calibration, the visibility phase across a clean 1.32-1.38 GHz band is flattened to a residual scatter of a few degrees. Using the calibrated visibilities, we form a four-antenna synthesis image of Cassiopeia A; the CLEANed image recovers a compact source at the phase center and reduces image-domain background fluctuations from order 0.1 to a few 0.01 Jy/beam. These results indicate that the software is suitable for small-array commissioning and initial synthesis imaging on QUEST. A GNSS-based beam measurement is included as a supporting commissioning check.
Keywords
Cite
@article{arxiv.2604.20640,
title = {A Python/CuPy Software Correlator for QUEST: Real-Time Performance and Initial Imaging},
author = {Jialang Ding and Guanhong Lin and Dejia Zhou and Jianli Zhang and Ran Duan and Fei Liu and Xiaoyun Ma and Jie Zhang and Meng Liu and Chenchen Miao and Yuan Liang and Liaoyuan Liu and Yingrou Zhan and Yuting Chu and Jing Qiao and Wei Wang and Zerui Wang and Menquan Liu and Meng Guo and Di Li and Pei Wang and Xuanyu Wang and Xiaohui Yan},
journal= {arXiv preprint arXiv:2604.20640},
year = {2026}
}