1. Department of Cartography and Graphic Expression in Engineering, University of Las Palmas de Gran Canaria, Campus de Tafira s/n, Las Palmas de Gran Canaria 35017, Canary Islands, Spain
2. Department of Electronics and Automatics Engineering, University of Las Palmas de Gran Canaria, Campus de Tafira s/n, Las Palmas de Gran Canaria 35017, Canary Islands, Spain