The Virginia Tech Formation Flying Testbed (VTFFTB), a GNSS‐based hardware‐in‐the‐loop (HIL) simulation testbed for spacecraft formation flight, is developed and applied to ionospheric remote sensing. The current VTFFTB consists of GNSS RF hardware signal simulators, multi‐constellation multi‐frequency GNSS receivers, a navigation and control system, an STK visualization system, and an ionospheric remote sensing system. GPS signals are emulated using GNSS simulator scenarios that include ionospheric phenomena. A formation of two spacecraft (“chief” and “deputy”) is considered. GNSS receiver data are used to produce space‐based Total Electron Content (TEC) and scintillation measurements. A reference low Earth orbit (LEO) scenario is benchmarked with past simulation results to validate functionality. A LEO formation flying mission is designed to probe two Equatorial Spread F (ESF) scenarios with plasma bubbles. The results investigate the structure of ionospheric irregularities and demonstrate that the GPS‐based satellite formation is able to measure vertical electron density by differencing 1D GPS vertical TEC.

中文翻译：

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基于GPS的卫星编队飞行模拟及其在电离层遥感中的应用

弗吉尼亚技术编队飞行试验台（VTFFTB）是用于航天器编队飞行的基于GNSS的硬件在环（HIL）仿真试验台，已开发并应用于电离层遥感。当前的VTFFTB由GNSS RF硬件信号模拟器，多星座多频率GNSS接收器，导航和控制系统，STK可视化系统以及电离层遥感系统组成。GPS信号是使用包括电离层现象的GNSS模拟器方案进行仿真的。考虑了两个航天器（“首席”和“副”）的编队。GNSS接收器数据用于产生基于空间的总电子含量（TEC）和闪烁测量。参考低地球轨道（LEO）方案以过去的模拟结果作为基准，以验证功能。LEO编队飞行任务旨在探测带有等离子气泡的两种赤道展宽F（ESF）情景。结果调查了电离层不规则结构，并证明了基于GPS的卫星编队能够通过差分一维GPS垂直TEC来测量垂直电子密度。