The flexible microwave payload-2: A SDR-based GNSS-reflectometer and L-Band radiometer for CubeSats

• Published in: IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing
• Main Authors: Muñoz Martin, Joan Francesc, Fernandez Capon, Lara Pilar, Ruiz De Azúa Ortega, Juan Adrián, Camps Carmona, Adriano José
• Other Authors: Universitat Politècnica de Catalunya. Doctorat en Teoria del Senyal i Comunicacions, Universitat Politècnica de Catalunya. Doctorat en Enginyeria Telemàtica, Universitat Politècnica de Catalunya. Departament de Teoria del Senyal i Comunicacions, Universitat Politècnica de Catalunya. RSLAB - Grup de Recerca en Teledetecció, Universitat Politècnica de Catalunya. WNG - Grup de xarxes sense fils
• Format: Article in Journal/Newspaper
• Language: English
• Published: Institute of Electrical and Electronics Engineers (IEEE) 2020
• Subjects: Àrees temàtiques de la UPC::Enginyeria de la telecomunicació; Optical communications; Cosmology; Microwave radiometry; L-band; CubeSat; Payloads; Sea ice; Ocean temperature; Satellite broadcasting; Nanosatèl·lits; Comunicacions òptiques; Cosmologia
• Online Access: http://hdl.handle.net/2117/339659; https://doi.org/10.1109/JSTARS.2020.2977959

This article presents the FMPL-2 on board the FSSCat mission, the 2017 ESA Small Sentinel Satellite Challenge and overall Copernicus Masters Competition winner. FMPL-2 is a passive microwave instrument based on a software-defined radio that implements a conventional global navigation satellite system-Reflectometer and an L-band radiometer, occupying 1 U of a 6 U CubeSat. The article describes the FSSC at mission context, the payload design and implementation phases, the tests results in a controlled environment, and finally the calibration algorithms applied to the downloaded data in order to extract the appropriate geophysical parameters: sea-ice coverage, sea-ice thickness (SIT), and low-resolution soil moisture. This article covers the overall payload design, from a high-level block diagram down to single-component specifications from both hardware and software points of view. The main block of the instrument is based on the combination of an FPGA, which virtualizes a dual-core ARM processor, where most of the calculus are performed, and a software-defined radio module, in charge of I/Q data demodulation. The article also explains the design and implementation of a signal conditioning board required for the correct operation and calibration of both instruments. The authors are with the Department of Signal Theory and Communications,Universitat Politècnica de Catalunya, Unidad de Excellencia María de Maeztu Peer Reviewed Postprint (published version)