A Study of (u, v) Coverage in Space Based VLBI Using Hybrid Satellite Orbits

Abstract

Space Very Long Baseline Interferometry (SVLBI) extends the capabilities of traditional radio interferometry by deploying satellites in Earth orbit, enabling micro-arcsecond angular resolution and access to low-frequency radio bands inaccessible from the ground. This article is the summarized preliminary study of effectiveness of the SVLBI consisting of hybrid orbit telescopes. Wherein, investigation of the (u, v) coverage produced by SVLBI systems with different satellite orbital configurations combining Low Earth Orbit (LEO), Medium Earth Orbit (MEO), and High Earth Orbit (HEO) satellites is performed. Configurations are evaluated for their ability to generate both short and long baselines, with attention to the trade-off between angular resolution and (u, v) sampling density. In particular, a hybrid MEO-LEO constellation offers uniform coverage suitable for imaging extended structures, while inclusion of a HEO satellite improves angular resolution. The combined HEO-MEO-LEO configuration achieves both high fidelity and resolution, making it a promising architecture for future low-frequency radio observations. Moreover, a detailed case study has been perform in the article submitted to Experimental Astronomy. © 2025 IEEE.