2026-04-14T05:57:22Zhttps://recercat.cat/oai/request

oai:recercat.cat:2117/4278512026-01-24T04:44:50Zcom_2072_1033col_2072_452950

00925njm 22002777a 4500 dc Khan, Shah Zahid author Abbas, Yasir author Edwar, Edwar author Jallad, Abdul-Halim author Camps Carmona, Adriano José author 2025-02-27 Recent developments in high-performance Software Defined Radios (SDR) and their utilization in CubeSat payloads are transforming Earth Observation (EO), including Microwave Radiometers, Global Navigation and Satellite System – Radio Occultations (GNSS-RO), and – Reflectometry (GNSS-R). In recent years, GNSS-R has been increasingly used in land and marine environmental monitoring, with applications expanding to other emerging fields in EO. The so called Delay Doppler Map (DDM) is the primary observable of GNSS-R receivers, providing information on surface properties, i.e. dielectric constant and surface roughness. Efficient on-board processing is essential in CubeSat-based GNSS-R missions, due to the large volume of raw data and the constraints of limited downlink bandwidth. However, limited on-board computational resources present challenges, as DDM generation requires intensive Fast Fourier Transform (FFT) operations. This study presents the design and development of a cost-effective and compact 0.5U GNSS-R CubeSat payload that optimizes the GNSS-R data processing technique by using the auxiliary data from the reference signals, such as Pseudo-Random Noise (PRN) codes, and their Doppler frequencies in order to reduce the search space. This way the payload selectively processes the raw data, significantly reducing the computational load. The payload processing unit is implemented in Analog Devices ADRV9364 with a dual-core ARM Cortex-A9 processor with a Zynq-7000 FPGA. This work was supported in part by ASPIRE ViP21-004 grant; and in part by United Arab Emirates University (UAEU). Peer Reviewed Postprint (published version) Àrees temàtiques de la UPC::Enginyeria de la telecomunicació::Radiocomunicació i exploració electromagnètica::Satèl·lits i ràdioenllaços Payloads CubeSat Antenna arrays Instruments Global navigation satellite system Global Positioning System Doppler effect Satellite broadcasting SAW filters Receiving antennas GNSS-R Reflectometry Interferometry Software Defined Radios (SDRs) Delay Doppler Map (DDM) Optimization An SDR-based GNSS-R CubeSat payload: hardware development and optimization of the onboard processing