Analysis of the communication links between the AlSat‐1b satellite and the ground station: The impact of the Auto Tracking system on antenna pointing accuracy

Abstract

Summary The communication links between a satellite and the Earth station (ES) are exposed to many impairments such as noise, rain, and atmospheric attenuations. They are also prone to loss such as those resulting from antenna pointing and polarization. The Algerian Earth Observation satellite AlSat‐1b is designed to accomplish its mission in S‐band (Telecommands and Telemetry) and X‐band (images) frequencies in low Earth orbit (LEO). The ground segment (GS) of this satellite, situated in Oran, Algeria, is based on the X/Y antenna mounting system with 7.3‐m dish diameter. This large reflector can cause antenna pointing errors. The Antenna Control Unit (ACU) implemented in this station can be configured with or without an AutoTrack system. In this work, operational tests and analysis of the different communication links between AlSat‐1b and the ground station are presented. The obtained results clearly show that the quality of the S‐band links can reliably and efficiently satisfy the requirements without the use of the AutoTrack. On the contrary, the use of AutoTrack is necessary in order to obtain an improved level of link quality in the X band.

Dynamically Balanced Pointing System for CubeSats: Study and 3D Printing Manufacturing

“…For example, in a real-time Earth observation scenario, the satellite is required to point its camera toward a specific point on the surface, while at the same time pointing its antenna toward the ground station or to another satellite. In larger satellites, this is generally achieved using an alt-azimuth mount on the antenna [22]; however this requires 2 degrees of freedom (DoF) and may prove impractical for small satellites.…”