Rover-Level Cross-Calibration of the Rosalind Franklin Rover’s Enfys and PanCam Instruments.

Description

Oral presentation at the Astrobiology Society of Britain 10th Conference (2025).

In late 2030, the European Space Agency’s Rosalind Franklin Rover will begin its journey across the Martian surface in search of past signs of life. Onboard is a suite of instruments to examine Martian geology and geochemistry. Amongst them is Enfys - an infrared spectrometer. Infrared observations can unlock the chemical makeup of the observed geology using a method known as “Geological fingerprinting” or “Infrared f ingerprinting”. Absorption features, typically within the shorter wavelength range of the IR spectrum, are diagnostic of key mineral groups expected to be present at the landing site including, but not limited to, silicates, carbonates, sulphates, and phyllosilicates (all of which are indicators of di erent geological processes and environmental conditions). Understanding the current surface of Mars is essential to deduce the planet's previous structure and potential past habitability. The identification of key minerals can provide details on the history of aqueous alteration processes on Mars – indications that liquid water, which is thought to be essential to life, was once present there. With Enfys being one of the first steps on the rover’s science pathway, it will be instrumental to the mission as a whole. Enfys uses reflected sunlight to measure the spectrum that is a combination of all the targets within its 1-degree field of view (FOV). This spectrum will be collated with the rover’s Panoramic Camera system – specifically the High-Resolution Camera (HRC) which is positioned directly above the Enfys instrument. Cross-calibration of these two instruments is essential for rover operations as HRC can provide the essential visual context to Enfys’ measurements. Improper cross-calibration can lead to confusing or unusable data capture. Cross-calibration will utilise a new method known as the “Automatic Crosscalibration Technique Utilising Albedo Luminance” or ACTUAL. ACTUAL was conceptualised by the Enfys PI Matt Gunn who then entrusted the planning, testing and development of the process to the author. It utilises the di erence in reflective properties between highly di usely reflective materials such as Spectralon contrasted against a low reflectivity background. By varying viewing angle and distance between the target and the system, it is possible to locate the instruments within each other’s field of view. Through testing with the Aberystwyth University PanCam Emulator (AUPE), a system was devised that minimises the number of times the rover’s Pan Tilt Unit (PTU) is moved, whilst also minimising the associated errors. ACTUAL will be applied to Amalia (the ground test model of the rover) and the real Rosalind Franklin in Turin once Enfys has been delivered early next year (2026). A brief introduction to Enfys as well as an overview of ACTUAL will be presented, including ACTUAL’s evolution from concepts to practice and preliminary results - an example of the process from start to finish using AUPE and the PanCam activity planning tool known as VelociRAPDer.

Period	18 Jun 2025
Held at	University of St Andrews, United Kingdom of Great Britain and Northern Ireland