Swarm intelligence for full Stokes dynamic imaging reconstruction of interferometric data

Abstract

In very long baseline interferometry (VLBI) the combination of multiple antennas permits the synthesis of a virtual telescope with a larger diameter and consequently higher resolution than the individual antennae. Yet, due to the sparse nature of the array, recovering an image from the observed data is a challenging ill-posed inverse problem. The VLBI community is interested in not only recovering an image in total intensity from interferometric data, but also to obtain results in the polarimetric and the temporal domain. Only a few algorithms are able to work in all these domains simultaneously. In particular, the algorithms based on optimization that consider various penalty terms specific to static total intensity imaging, time-variability and polarimetry are restricted to grids the domain of the objective function. In this work we present a novel algorithm, multiobjective particle swarm optimization, that is able to recover the optimal weights without any space-gridding, and to obtain the marginal contribution of each the playing terms. To this end, we utilize multiobjective optimization together with particle swarm metaheuristics. We let the swarm of weights to converge together to the best position. We evaluate our algorithm with representative synthetic data sets focused on the instrumental configuration of the Event Horizon Telescope Collaboration and its planned successors. We successfully recover the polarimetric, static and time-dynamic signature of the ground truth movie, even with relative sparsity, and a set of realistic data corruptions. This is a novel, fast, weighting space gridding-free algorithm that successfully recovers static and dynamic polarimetric reconstructions. Compared to Regularized Maximum Likelihood methods, it avoids the need for parameter surveys, and it is not limited to the number of pixels such as recently proposed multiobjective imaging algorithms.

Accepted in A&A

References in corpus (16)

• First M87 Event Horizon Telescope Results. IV. Imaging the Central Supermassive Black Hole
• WSClean: an implementation of a fast, generic wide-field imager for radio astronomy
• Multi-Scale CLEAN deconvolution of radio synthesis images
• First Sagittarius A* Event Horizon Telescope Results. III: Imaging of the Galactic Center Supermassive Black Hole
• Imaging the Schwarzschild-radius-scale Structure of M87 with the Event Horizon Telescope using Sparse Modeling
• Super-resolution Full Polarimetric Imaging for Radio Interferometry with Sparse Modeling
• Evaluation of New Submillimeter VLBI Sites for the Event Horizon Telescope
• Discriminating Accretion States via Rotational Symmetry in Simulated Polarimetric Images of M87
• Hybrid Very Long Baseline Interferometry Imaging and Modeling with Themis
• Unified Radio Interferometric Calibration and Imaging with Joint Uncertainty Quantification
• Spurious source generation in mapping from noisy phase-self-calibrated data
• Selective Dynamical Imaging of Interferometric Data
• An Updated Formalism For Line-Driven Radiative Acceleration and Implications for Stellar Mass Loss
• Multi-scale and Multi-directional VLBI Imaging with CLEAN
• Dynamic and polarimetric VLBI imaging with a multiscalar approach
• Robust analysis of differential Faraday Rotation based on interferometric closure observables

Cited by in corpus (9)

• Bayesian self-calibration and imaging in Very Long Baseline Interferometry
• Imaging a ring-like structure and the extended jet of M87 at 86 GHz
• Deep learning inference with the Event Horizon Telescope II. The Zingularity framework for Bayesian artificial neural networks
• How to make CLEAN variants faster? Using clustered components informed by the autocorrelation function
• Prospects of using closure traces directly for imaging in Very Long Baseline Interferometry
• Probing circular polarization and magnetic field structure in AGN
• Accelerating the CLEAN algorithm of radio interferometry with convex optimization
• Very-Long Baseline Interferometry Imaging with Closure Invariants using Conditional Image Diffusion
• Multiobjective optimization for scattering mitigation and scattering screen reconstruction in VLBI observations of the Galactic Center