Development of an advanced nano-satellite (VELOX-IV) : ground station

• Main Author: Lai, Xingjie
• Other Authors: Low Kay Soon
• Format: Final Year Project
• Language: English
• Published: 2016
• Subjects: DRNTU::Engineering
• Online Access: http://hdl.handle.net/10356/67796
• Institution: Nanyang Technological University

The Satellite Research Centre (SaRC) in NTU has successfully launched six satellites since 2011. To communicate with these satellites in orbit, there are two ground stations; one at NTU Block S2 which uses the UHF and VHF amateur radio band for communication with the Nano-satellites and the other at Research Techno Plaza which uses the S- & X-band for communication with the VELOX-CI micro-satellite. The main objective of this project is to develop a ground station communication system to support future Nano-satellites missions using S-Band for satellite-to-ground communication. In this project, the use of the Command, Ranging and Telemetry (CRT) equipment for satellite telemetry processing and telecommanding at intermediate frequency level has been investigated. A graphical user-interface (GUI) has been successfully developed using Java for communication with the CRT unit using a remote computer via TCP/IP. With the GUI, telemetry commands can be sent to control the CRT. The program developed serves a base code for interfacing the CRT unit with the existing mission control platform and allows for additional mission commands to be included in the future. Simulations has been conducted using MATLAB to evaluate the bit error rate (BER) to energy per bit to the noise power spectral density ratio (Eb/N0) for different modulation schemes and coding. The results show that a higher Eb/N0 is required for 8QAM than BPSK/QPSK for the same BER. Modulation with Hamming code further lowers the Eb/No requirement compared to uncoded modulation for the same BER. A link budget analysis has also been performed for a Nano-satellite using a legacy S-Band transceiver for communication with the existing S-Band ground station. The analysis show that in the worst case, the ground station will have at least an uplink margin of 34.70 dB and a downlink margin of 8.91 dB. This shows that there are sufficient link margins for the Nano-satellite to receive and transmit a BPSK/ QPSK signal with a BER of 〖10〗^(-6) to the existing NTU ground station.