“…It was developed during three European COoperation in Science and Technology (COST) Short-Term Scientific Missions (STSMs), as a contribution to the COST Action TU1208 "Civil Engineering Applications of Ground Penetrating Radar" [7]. Those STSMs were carried out in May 2015 [8], [9], January 2016 [10]- [12], and December 2016 -January 2017 [13], [14]. In applications involving smart antennas and in the presence of several transmitters operating simultaneously, it is important for a receiving array to be able to estimate the Directions of Arrival (DoAs) of the incoming signals, in order to decipher how many emitters are present and predict their positions [15], [16].…”