用于高精度全球导航卫星系统（GNSS）的地空参考网络协调
Coordination of Ground-to-Space Reference Networks for High-Precision GNSS
AI总结：
针对现有地空GNSS参考网络架构中通信链路的局限，本文提出分布式处理架构，将地面站与LEO卫星建模为动态图交互子网络，协调地空参考网络以提升GNSS修正量生成的可靠性。
AI中文摘要：
高精度全球导航卫星系统（GNSS）服务依赖于从参考观测值生成的精确轨道、时钟、大气及硬件偏差修正量，这些产品传统上由地面参考网络推导而来，其性能高度依赖地面站的密度与地理分布。因此，稀疏或区域集中的网络会出现跟踪间隙、全球可观测性受限的问题，削弱其支持全球一致高精度产品的能力。配备星载GNSS接收机和星间链路（ISL）的低地球轨道（LEO）星座可作为星载参考站网络，为将地面参考网络扩展至空间提供了可行方案，进而提升地面网络的可观测性，支持未来直接修正量广播。然而，现有多数基于网络的GNSS修正量生成工作流假设观测值可被集中收集与处理，该假设在实际地空架构中不成立——动态卫星几何结构与系统约束会导致通信链路间歇性、不对称、容量受限且易丢失。为解决这些局限，本文提出一种协调地空GNSS参考网络的分布式处理架构，通过将地面站与LEO卫星建模为动态图上的交互子网络，该方法允许层级内频繁通信，同时将跨层级交换限制为在概率链路可用性下机会性传输的紧凑估计摘要。
英文摘要：
High-precision Global Navigation Satellite System (GNSS) services rely on accurate orbit, clock, atmospheric, and hardware-bias corrections generated from reference observations. These products are traditionally derived from terrestrial reference networks, whose performance strongly depends on the density and geographic distribution of ground stations. Consequently, sparse or regionally concentrated networks can suffer from tracking gaps and limited global observability, reducing their ability to support globally consistent high-precision products. Low Earth Orbit (LEO) constellations equipped with onboard GNSS receivers and inter-satellite links (ISLs) can serve as a network of spaceborne reference stations, offering a promising way to extend terrestrial reference networks into space, thereby improving observability for ground networks and enabling future direct correction broadcast. However, most existing network-based GNSS correction-generation workflows assume that observations can be centrally collected and processed. This assumption fails in practical ground--to--space architectures, where dynamic satellite geometry and system constraints render communication links intermittent, asymmetric, capacity-limited, and lossy. To address these limitations, this paper proposes a decentralized processing architecture that coordinates the ground-to-space GNSS reference network. By modeling ground stations and LEO satellites as interacting subnetworks over a dynamic graph, our approach allows frequent intra-tier communication while restricting cross-tier exchanges to compact estimation summaries transmitted opportunistically under probabilistic link availability....
