FlyRadar: a penetrating and synthetic aperture radar mounted on light UAV for the exploration of Earth and planets
Authors: Ori Gian Gabriele , Allemand Pascal , Keresturi Akos , Mège Daniel , Alberti Gianni , Grandjean Philippe , Mancini Francesca , Augier Sylvain , Kofman Wlodek , Gurgurewicz Joanna , Castel Alexandre , Neir Olivier , Senz Titus , Orlanducci Claudio , Kirillova Aino 
Published: July 2024

The FlyRadar Project involves a collaboration between various University institutions and Companies to develop and evaluate a multi-mode (penetrating and SAR) multi-frequency radar system mounted on a UAV designed for exploration on Mars and conducting surveys on Earth. This project has received funding from the European Commission under the H2020-MSCA-RISE framework.&#160;The FlyRadar project is structured based on technical, scientific, and qualification tasks. Radar characteristics have been determined based on scientific expectations. The radar is a versatile radar system that operates at multiple modes and frequencies. Specifically, it operates at a frequency of 435 MHz for short-range operations and is designed to be installed on an electric quadcopter UAV. The radar system includes SAR (Synthetic Aperture Radar) and echo sounder modes. These modes enable a wide range of applications in remote sensing exploration, particularly in the fields of geology, agronomy, subsurface artifacts, hydrology, archaeology, and more, both on Earth and other planetary environments. Compared to other radar tools like SHARAD and MARSIS, which operate at lower frequencies, the FlyRadar tool offers a higher resolution but has a lower penetration depth. This means that it can provide detailed characterization of shallower features in the crust, typically within tens of meters, with enhanced clarity. The design of the radar system takes into account various aspects, including mechanical, electrical, electronic, optical, sensor, software control, and thermal analysis. Furthermore, scientific and operational considerations are also incorporated. Additionally, an efficient data processing chain has been implemented to handle the radar data effectively.&#160;The Unmanned Aerial Vehicle (UAV) has been specifically engineered to accommodate the weight and size of the FlyRadar instrument. Both the airborne and ground components, including mechanical, electrical, electronic, and sensor systems, have been meticulously integrated, taking into account scientific and operational requirements. A comprehensive qualification program was implemented to assess the performance of each individual element as well as the entire system.&#160;FlyRadar was developed for the purpose of studying planetary surfaces, including Earth. The system can be utilized on our planet for detailed analysis using synthetic aperture data to map out archaeological sites, conduct high-resolution surveys of surfaces and the immediate subsurface. The penetration mode is capable of collecting data on the subsurface up to a few tens of meters deep, depending on the water content of the materials in the subsurface. In addition to its applications on Earth, FlyRadar aims to serve as a prototype for planetary exploration by offering surface characterization and subsurface support. It has the potential to be a valuable tool for mapping lava tunnels, identifying ice covered by debris (particularly in glacial regions), determining the thickness of regolith, and more. Mars is an ideal candidate for exploration utilizing advanced technology. The surface of Mars is covered with a diverse range of rocks, including volcanic, sedimentary, and impact rocks, which are clearly visible. Additionally, Mars boasts two permanent polar ice caps and various ice masses hidden beneath the surface in the mid-latitude region. The 3D structure of these geological formations remains largely unexplored, but can be investigated using a GPR-SAR tool. The effectiveness of Ground Penetrating Radar (GPR) has already been proven on Mars, as demonstrated. Over the past two decades, two orbital radar instruments, MARSIS on Mars Express and SHARAD on MRO, have successfully provided the first subsoil images of Mars. The RimFax instrument on the Perseverance rover has been active, delivering high-resolution images of the Jezero delta on Mars. The FlyRadar system, which will be mounted on a UAV and operate several tens of meters above the Martian surface, will provide precise and detailed data essential for future Mars sample return missions and human expeditions.