Vector Magnetometry Using Remotely Piloted Aircraft Systems: An Example of Application for Planetary Exploration

Geomagnetic prospection is an efficient and environmentally friendly geophysical method for the analysis of the magnetic minerals’ distribution in the subsurface. High-resolution measurements require on-ground campaigns. However, these activities might imply high costs, risk and time consumption. Some more recent works have started to use magnetometers on-board remote piloted aircrafts. Normally, they fly at a constant altitude and use scalar probes. This configuration permits the determination of the magnitude of the magnetic field but not the direction, and requires advanced techniques for in-depth interpretation of the sources. In this manuscript, we describe the accommodation of a system for vector magnetometry in a drone whose flight altitude follows the elevation of the terrain. This singularity improves the capability of interpretation, including constraints in dating due to the record of the geomagnetic field. The work consists of the design, development and implementation of a solidary payload system anchored to the body of the platform in order to determine the vector magnetic field. It describes the details of the system and the performance characteristics obtained after the calibration, as well as its demonstration via a field campaign in the spatter deposits of Cerro Gordo volcano in Campos de Calatrava volcanic province in Spain.

Plasma observations during the Mars atmospheric "plume" event of March-April 2012

We present initial analysis and conclusions from plasma observations made during the reported "Mars plume event" of March - April 2012. During this period, multiple independent amateur observers detected a localized, high-altitude "plume" over the Martian dawn terminator [Sanchez-Lavega et al., Nature, 2015, doi:10.1038/nature14162], the cause of which remains to be explained. The estimated brightness of the plume exceeds that expected for auroral emissions, and its projected altitude greatly exceeds that at which clouds are expected to form. We report on in-situ measurements of ionospheric plasma density and solar wind parameters throughout this interval made by Mars Express, obtained over the same surface region, but at the opposing terminator. Measurements in the ionosphere at the corresponding location frequently show a disturbed structure, though this is not atypical for such regions with intense crustal magnetic fields. We tentatively conclude that the formation and/or transport of this plume to the altitudes where it was observed could be due in part to the result of a large interplanetary coronal mass ejection (ICME) encountering the Martian system. Interestingly, we note that the only similar plume detection in May 1997 may also have been associated with a large ICME impact at Mars.