High-precision orbits of Low Earth Orbit (LEO) satellites are essential for many scientific applications, such as assessing the change in current global mean sea level, estimating coefficients gravity field, and so on. How to determinate high-precision LEO has gradually become an important research focus. HY2D is a new altimetry satellite China, which equipped with Global Positioning System (GP...

In recent years, low Earth orbit (LEO) satellites have been frequently discussed for their benefits in positioning and navigation services as an augmentation to the global satellite systems (GNSSs). Similar concept based on ranging GNSS satellites, precise of single-receiver users needs high-accuracy orbits clocks LEO a pre-condition. For real-time users, high prediction accuracies these at dif...

The advent of low earth orbit (LEO) commercial communication satellites provides an opportunity to dramatically reduce Telemetry, Tracking and Control (TT&C) costs of launch vehicles, Unpiloted Aerial Vehicles (UAVs), Research Balloons and spacecraft by reducing or eliminating ground infrastructure. Personnel from the Goddard Space Flight Center’s Wallops Flight Facility (GSFC\WFF) have success...

Low-Earth orbit (LEO) satellite networks are meant to be fundamental closing the digital divide, enabling new market opportunities and providing fifth-generation (5G) New Radio (NR) connectivity everywhere at any time. Despite advantages of LEO deployments, these systems characterized by a high mobility challenging propagation channel that compromise several procedures current 5G standards. One...

Haiyang-2D (HY-2D) is the fourth satellite in marine dynamic series established by China. It was successfully launched on 19 May 2021, marking era of 3-satellite network environment The satellite’s precision orbit determination (POD) and validations are great significance for ocean warning altimetry missions. HY-2D equipped with a laser reflector array (LRA), satellite-borne Doppler Orbitograph...

In this paper, we investigate the effect of strong time-varying transmission distance on performance low-earth orbit (LEO) satellite-terrestrial (STT) system. We propose a new analytical framework using finite-state Markov channel (FSMC) model and time discretization method. Moreover, to demonstrate applications proposed framework, performances two adaptive transmissions, rate-adaptive (RAT) po...

In this article, we investigate the issue of massive access in a beyond fifth-generation (B5G) multibeam low-Earth orbit (LEO) satellite Internet-of-Things (IoT) network presence channel phase uncertainty due to channel-state information (CSI) conveyance from devices via gateway. Rather than time-division multiple (TDMA) or frequency-division (FDMA) with multicolor pattern, new nonorthogonal (N...

The objectives of on-orbit servicing (OOS) missions include manipulation, proximity operations and inspection of target satellites. Therefore the servicer satellite often has to be teleoperated at low latency for several minutes to fulfill these tasks. That means communication plays a crucial role for OOS missions because real time teleoperation including high data rates has to be realized. So ...

To meet an ever-growing demand for wideband multimedia services and electronic connectivity across the world, development of ubiquitous broadband multimedia systems is gaining a tremendous interest at both commercial and academic levels. Satellite networks will play an indispensable role in the deployment of such systems. A significant number of satellite communication constellations have been ...