Algorithm 1. Pseudo-code of the WQS algorithm based on miscellaneous SOPs

Requires: 1. Fingerprint database Fpdb = $(P{<x,y,soplist,w>}_1, P{<x,y,soplist,w>}_2,\dots ,P{<x,y,soplist,w>}_n)$;

2. Fingerprint information at unknown position Fpx = (${sop}_1,{sop}_2,\dots ,{sop}_n$);

Setting: ${\text{δ}}_1,{\text{δ}}_2\dots {\text{δ}}_m$ (thresholds) for each type of SOP

for each sop measurement in Fingerprint Fpx

if $abs({sop}_i-{soplist}_j)< {\text{δ}}_1$

$w_j= w_j+1$ (weight increased only when the sop measurement follows the weight δ-selecting criteria )

end for

end for

return $P_{\text{mean}}=\frac{\left(w_{m1}+w_{m2}\right)*P_1+\left(w_{m2}+w_{m3}\right)*P_2+\left(w_{m1}+w_{m3}\right)*P_3}{2*(w_{m1}+w_{m2}+w_{m3})},$

which is the mean position of the three positions with the maximum weight $w_{max}$