The field site campaign carried out by The Group of Atmospheric Science at Río Tinto, Spain, has come to its end after three days of works, focused on the geochemical and paleogeological studies of certain locations within the area. The main task of the GAS’s team, composed of Anshuman Bhardwaj and Juan Antonio Ramírez, has consisted of the mapping of the sampling sites by means of the Group’s drone for getting Digital Terrain Models (DTM) of them, thus highlighting the significance of drones as fast-emerging remote sensing platforms for providing reliable terrain data at unprecedented resolutions.
The scientific objectives of the campaign were to collect the baseline data for further studying the formation and distribution of acidic salts and of the compositional changes of the acidic mineral in the ancient Rio Tinto deposits, the characterization of mineral species that are associated to the acidic solutions in the different springs, and the evaluation of preservation of the molecular biosignatures in ancient deposits of acidic evaporites.
GAS’s drone has been applied to the imaging of all the sampling points, whose analysis will permit to give context to the obtained data, both in spatial and temporal terms. In this latter sense, the image analysis will make possible to figure out the evolution of the studied features, to trace back the geochemical and biological processes involved in the shaping of the area. More than two thousand high resolution images for thirteen different sites have been recorded throughout three days of work. This is the first instance that such drone-based contextual mapping for geoscientific investigations has been performed in the study sites.
Apart from the better understanding of the history of this outstanding zone, the investigations to be performed will pose the comparison with ancient Martian environment, which is thought to have been dominated by global acidic conditions (such as those present now in Río Tinto) according to the known widespread occurrence of sulphate and oxide minerals. Regarding the search for signs of life on Mars, Río Tinto can provide crucial information not only to determine what should be looked for; the imagery study will also offer a reliable depiction of where it should be sought.
Unmanned Aerial Vehicles (UAVs) such as the used drone, have increased (among other things) the possibilities for the enrichment of different kind of studies performed in field site campaigns by providing terrain modelling based on remote imaging. They offer a great flexibility of use overcoming the constraints to which the airborne platforms are submitted to (costs, flight levels, timing of data acquisition), as well as high resolution imagery. A highlight of the campaign was to perform in-situ flight planning even in the vegetated regions based on localised areas of geomorphological interest which otherwise would be difficult to locate in the satellite images. The automated flight plans guided the UAV perfectly and now the next step will be processing of the collected images to generate high-resolution terrain models and orthomosaics.
Now, as another example of the multiple uses and different studies a UVA can be applied to, GAS’s drone is mapping the archaeological site of Cástulo, in Linares, Spain, an old Iberian-Roman city whose study is going to be supported on the image analysis provided.