Fig. 4

Derivation of the maper formulae for cell-id technique. Angles are represented by greek letters, vectors by bold latin letters and lengths by both latin and greek letters. The angles are oriented towards an axis parallel to the vector \(\mathbf {X_{n-1}X_{n}}\) in a counterclockwise direction. The maper occurs at the boundary of the region delimited by the tag’s signal, here a circle centered at \(\mathbf {P_n}\) and with radius r.