**Author details**

Benjamin Arias-Perez Department of Cartographic and Land Engineering, University of Salamanca, Ávila, Spain

\*Address all correspondence to: benja@usal.es

© 2021 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/ by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
