The Radar Imager for Mars' subsurface experiment (RIMFAX) is a

ground-penetrating radar Ground-penetrating radar (GPR) is a Geophysics, geophysical method that uses radar pulses to Geophysical imaging, image the subsurface. It is a non-intrusive method of surveying the sub-surface to investigate underground utilities such as concrete, ...

NASA The National Aeronautics and Space Administration (NASA ) is an independent agency of the US federal government responsible for the civil space program, aeronautics research, and space research. NASA was established in 1958, succeedi ...

's ''Perseverance'' rover, part of the

Mars 2020 Mars 2020 is a Mars rover mission forming part of NASA's Mars Exploration Program that includes the rover '' Perseverance'', the small robotic, coaxial helicopter '' Ingenuity'', and associated delivery vehicles. Mars 2020 was launched from ...

mission. It uses radar waves to see geologic features under the surface. The device can make detections perhaps dozens of meters/yards underneath ground, such as for buried sand dunes or lava feature. During development a detection range of about 10 yards/meters was targeted, and tests on glaciers were successful. RIMFAX takes its name from Hrímfaxi, the horse in

Norse mythology Norse, Nordic, or Scandinavian mythology is the body of myths belonging to the North Germanic peoples, stemming from Old Norse religion and continuing after the Christianization of Scandinavia, and into the Nordic folklore of the modern peri ...

that "faithfully brings the night." The radar will operate at radio frequencies of 150–1200 MHz and will use a Bow-Tie

Slot antenna A slot antenna consists of a metal surface, usually a flat plate, with one or more holes or slots cut out. When the plate is driven as an antenna by an applied radio frequency current, the slot radiates electromagnetic waves in a way similar to ...

Overview

RIMFAX is a

, its antenna is located on the lower rear of the ''Perseverance'' rover. It will be able to image different ground densities, structural layers, buried rocks,

meteorite A meteorite is a solid piece of debris from an object, such as a comet, asteroid, or meteoroid, that originates in outer space and survives its passage through the atmosphere to reach the surface of a planet or moon. When the original object en ...

s, and detect underground water ice and salty

brine Brine is a high-concentration Solution (chemistry), solution of salt (NaCl) in water (H2O). In diverse contexts, ''brine'' may refer to the salt solutions ranging from about 3.5% (a typical concentration of seawater, on the lower end of that of ...

at depth. Ground-penetrating radars (GPR) send radio frequency

electromagnetic waves In physics, electromagnetic radiation (EMR) consists of waves of the electromagnetic (EM) field, which propagate through space and carry momentum and electromagnetic radiant energy. It includes radio waves, microwaves, infrared, (visible) lig ...

into the ground and then detect the reflected signals as a function of time to reveal subsurface structure as well as composition. RIMFAX is based on a number of GPR instruments developed at the

Norwegian Defence Research Establishment The Norwegian Defence Research Establishment (''Forsvarets forskningsinstitutt'' – ''FFI'') is a research institute that conducts research and development on behalf of the Norwegian Armed Forces and provides expert advice to political and mi ...

(FFI). RIMFAX was selected by NASA to be one of the instruments on the Mars 2020 rover in July 2014. RIMFAX will provide the science team with the capability to assess the shallow layers and their stratigraphic relationship to nearby outcrops, and thus a window into the geological history and associated environmental history. The RIMFAX instrument was developed and built by FFI, and it was delivered to NASA's

Jet Propulsion Laboratory The Jet Propulsion Laboratory (JPL) is a federally funded research and development center and NASA field center in the City of La Cañada Flintridge, California, United States. Founded in the 1930s by Caltech researchers, JPL is owned by NASA ...

for integration with the rover in December 2018. Due to Mars's 24.5 hour long day, RIMFAX operations are shared between centers at

University of California, Los Angeles The University of California, Los Angeles (UCLA) is a public university, public Land-grant university, land-grant research university in Los Angeles, California. UCLA's academic roots were established in 1881 as a Normal school, teachers colle ...

(UCLA) and the

University of Oslo The University of Oslo ( no, Universitetet i Oslo; la, Universitas Osloensis) is a public research university located in Oslo, Norway. It is the highest ranked and oldest university in Norway. It is consistently ranked among the top univers ...

(UiO), swapping every two weeks. The RIMFAX data will be archived by NASA's Planetary Data System. The RIMFAX principal investigator is Svein-Erik Hamran of FFI, and his team includes scientists from

Norway Norway, officially the Kingdom of Norway, is a Nordic country in Northern Europe, the mainland territory of which comprises the western and northernmost portion of the Scandinavian Peninsula. The remote Arctic island of Jan Mayen and t ...

Canada Canada is a country in North America. Its ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, covering over , making it the world's second-largest country by tota ...

and the

United States The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 U.S. state, states, a Washington, D.C., federal district, five ma ...

Specifications

RIMFAX employs a gated

Frequency Modulated Continuous Wave Continuous-wave radar (CW radar) is a type of radar system where a known stable frequency continuous wave radio energy is transmitted and then received from any reflecting objects. Individual objects can be detected using the Doppler effect, which ...

(FMCW) waveform to probe the subsurface. Gated FMCW utilizes a single antenna for both transmission and reception, quickly switching the antenna between the transmitter and the receiver. RIMFAX will be commanded to acquire radar soundings every 10–20 cm along the rover's path to create two-dimensional GPR images of subsurface structure. PIA24206-MarsPerseveranceRover-RIMFAX-20210120

PIA24206-MarsPerseveranceRover-RIMFAX-20210120

Development

An engineering model of RIMFAX was tested in several locations, primarily in Svalbard, and in the US Southwest. Modelling was carried out with gprMax, an

open source Open source is source code that is made freely available for possible modification and redistribution. Products include permission to use the source code, design documents, or content of the product. The open-source model is a decentralized sof ...

electromagnetic simulation Computational electromagnetics (CEM), computational electrodynamics or electromagnetic modeling is the process of modeling the interaction of electromagnetic fields with physical objects and the environment. It typically involves using computer ...

tool, to assess the imaging potential at the landing site.

Contemporaries

Other Mars radar experiments include

SHARAD Sharad/Sarath/Sharath ( sa, शरद्)is the autumn season or ritu in the Hindu calendar. It roughly corresponds to the western months of mid-September to mid-November. Sharad is preceded by Varsha and followed by Hemant. The Hindu calendar c ...

, MARSIS, and

WISDOM Wisdom, sapience, or sagacity is the ability to contemplate and act using knowledge, experience, understanding, common sense and insight. Wisdom is associated with attributes such as unbiased judgment, compassion, experiential self-knowled ...

External links

* NAS
project homepage
* FF
project homepage

on the Planetary Data System
gprMAX
Electromagnetic simulation software

References