@conference {, title = {Coverage Anaylisis of an Ultrasonic Local Positioning System according to the Angle of Inclination of the Beacons Structure.}, booktitle = {International Conference on Indoor Positioning and Indoor Navigation }, year = {2019}, month = {10/2019}, pages = {1-8}, publisher = {IPIN}, organization = {IPIN}, address = {Pisa, Italia}, author = {Gualda, D and F. Ciudad and J.J. Garcia and Jimenez, A. and M.C.P{\'e}rez and Ure{\~n}a, J.} }