Martian magnetism with orbiting sub-millimeter sensor: simulated retrieval system

Richard Larsson,Catherine Diéval,Stefan Alexander Buehler,Mathias Milz,Jana Mendrok,David Brain,Paul Hartogh,Patrick Eriksson,Yasuko Kasai

doi:10.5194/gi-6-27-2017

Abstract

Abstract. A Mars-orbiting sub-millimeter sensor can be used to retrieve the magnetic field at low altitudes over large areas of significant planetary crustal magnetism of the surface of Mars from measurements of circularly polarized radiation emitted by the 368 GHz ground-state molecular oxygen absorption line. We design a full retrieval system for one example orbit to show the expected accuracies on the magnetic field components that one realization of such a Mars satellite mission could achieve. For one set of measurements around a tangent profile, we find that the two horizontal components of the magnetic field can be measured at about 200 nT error with a vertical resolution of around 4 km from 6 up to 70 km in tangent altitude. The error is similar regardless of the true strength of the magnetic field, and it can be reduced by repeated measurements over the same area. The method and some of its potential pitfalls are described and discussed.

Highlights

In the past decades, there have been several proposals to fly a sub-millimeter sensor on a satellite mission to Mars
With this work we aim to develop the idea presented by Larsson et al (2013) for remote measurement of magnetism by utilizing the Zeeman effect (Zeeman, 1897) on molecular oxygen in its ground state: X(3 g−)
The vertical resolution is about 4 km for Bu and Bv over the entire sensitive altitude range because it is perpendicular to the line of sight in the limb geometry, which reflects the achievable resolution for the simulated antenna size and tangent profile altitude spacing

Summary

Introduction

There have been several proposals to fly a sub-millimeter sensor on a satellite mission to Mars. Kasai et al (2012) show that molecular oxygen, carbon monoxide, water (even heavy water), ozone, isotopologues of carbon dioxide, hydrogen peroxide, and various other hydrogen radicals all should have strong signals in the spectrum of Mars which they propose to observe. With this work we aim to develop the idea presented by Larsson et al (2013) for remote measurement of magnetism by utilizing the Zeeman effect (Zeeman, 1897) on molecular oxygen in its ground state: X(3 g−). It is possible to combine this work with the idea of Kasai et al (2012) into a single instrument that is capable of measuring and mapping both meteorological parameters and crustal magnetic structures, but this work will only focus on the magnetic aspects of flying such an instrument

Objectives

Methods

Results

Conclusion