Rimfax – georadaren som skal til Mars

Hvordan skal Nasa finne ut hva som skjuler seg under overflaten på Mars? 

FFI har laget og levert radaren Rimfax. Den skal hjelpe Nasa med å utforske hva som skjuler seg under overflaten på Mars.

Georadaren Rimfax er en av de syv vitenskapelige instrumentene som skal sitte på Nasa-roveren "Perceveranse", som lander på Mars i februar 2021. Roverens oppgave er å lete etter rester etter liv. Radaren skal analysere de ulike geologiske lagene i bakken for å finne ut hvor det er lurest å ta prøver.

Rimfax - eller Radar Imager for Mars' subsurface experiment - er en georadar som kan "se" ned i bakken. Georadarer av denne typen kan også brukes til arkeologi og til å forske på snøskred. På Mars skal romversjonen Rimfax se ned i bakken og undersøke geologien flere meter under overflaten.

Fakta om Nasas Mars Mission

Launch Window
July 30 - Aug. 15, 2020

Launch Location
Cape Canaveral Air Force Station, Florida

Feb. 18, 2021

Landing Site
Jezero Crater, Mars

Mission Duration
At least one Mars year (about 687 Earth days)

I august var to forskere fra FFI hos Jet Propulsion Laboratory (PJL) i California for å sjekke at alt gikk riktig for seg da antenna til georadaren Rimfax ble montert på Nasas Mars-rover 2020. Byggingen av hele roveren ble sendt live på Youtube. Video: Nasa/JPL-Caltech
I 2020 skal radaren Rimfax ut på et romeventyr. Den skal ombord på Nasas romsonde og undersøke hva som skjuler seg under overflaten på planeten Mars. Her får du innblikk i hvordan FFI-forskerne tester radaren på Svalbard.
I denne animasjonen ser du Nasas rover som skal til Mars i 2020 - med den FFI-utviklete Rimfax-radaren om bord. Animasjon: Nasa/JPL-Caltech.

Relevante vitenskapelige artikler

Vitenskapelig artikkel 2017

The WISDOM Radar: Unveiling the Subsurface Beneath the ExoMars Rover and Identifying the Best Locations for Drilling

The search for evidence of past or present life on Mars is the principal objective of the 2020 ESA-Roscosmos ExoMars Rover mission. If such evidence is to be found anywhere, it will most likely be in the subsurface, where organic molecules are shielded from the destructive effects of ionizing radiation and atmospheric oxidants. For this reason, the ExoMars Rover mission has been optimized to investigate the subsurface to identify, understand, and sample those locations where conditions for the preservation of evidence of past life are most likely to be found. The Water Ice Subsurface Deposit Observation on Mars (WISDOM) ground-penetrating radar has been designed to provide information about the nature of the shallow subsurface over depth ranging from 3 to 10 m (with a vertical resolution of up to 3 cm), depending on the dielectric properties of the regolith. This depth range is critical to understanding the geologic evolution stratigraphy and distribution and state of subsurface H2O, which provide important clues in the search for life and the identification of optimal drilling sites for investigation and sampling by the Rover's 2-m drill. WISDOM will help ensure the safety and success of drilling operations by identification of potential hazards that might interfere with retrieval of subsurface samples. Key Words: Ground penetrating radar—Martian shallow subsurface—ExoMars.
Vitenskapelig artikkel 2017

Bitstream radar waveforms for generic single-chip radar

A Digital-to-Time converter (DTC) based on static CMOS multiplexers is presented, achieving a time resolution of 65 ps consuming 0.5 mW. The DTC relies on gate delay for programmability, ensuring robustness, linearity and wide delay range. Details of the transistor implementation (with sizes) is given, together with a detailed discussion on critical design points. Post layout simulations with Monte Carlo, voltage and temperature variations are presented with measurements from two different chip realizations in 90 nm CMOS.
Vitenskapelig artikkel 2015

In-Body to On-Body Ultrawideband Propagation Model Derived from Measurements in Living Animals

Ultra wideband (UWB) radio technology for wireless implants has gained significant attention. UWB enables the fabrication of faster and smaller transceivers with ultra low power consumption, which may be integrated into more sophisticated implantable biomedical sensors and actuators. Nevertheless, the large path loss suffered by UWB signals propagating through inhomogeneous layers of biological tissues is a major hindering factor. For the optimal design of implantable transceivers, the accurate characterization of the UWB radio propagation in living biological tissues is indispensable. Channel measurements in phantoms and numerical simulations with digital anatomical models provide good initial insight into the expected path loss in complex propagation media like the human body, but they often fail to capture the effects of blood circulation, respiration, and temperature gradients of a living subject. Therefore, we performed UWB channel measurements within 1-6 GHz on two living porcine subjects because of the anatomical resemblance with an average human torso. We present for the first time a path loss model derived from these invivo measurements, which includes the frequency-dependent attenuation. The use of multiple on-body receiving antennas to combat the high propagation losses in implant radio channels was also investigated.
Vitenskapelig artikkel 2015

Harmonic Synthetic Aperture Radar Processing

We review the basic concept of frequency-modulated continuous wave (FMCW) and describe how such a radar system can be used in a harmonic radar concept. It is argued that synthetic aperture radar (SAR) for FMCW harmonic radar can be implemented by carefully choosing the wavenumbers in the mixing part of the FMCW concept. It is also argued that the following SAR processing is an extension of conventional SAR processing when applied to a harmonic FMCW system.