Top: blob density distribution n_e,blb along the LOS coordinate z for the case (A) of constant density (solid blue line) and the case (B) of gaussian density distribution (solid red line). For future reference this figure also shows the folded density distributions (see text) corresponding to the constant density blob (dashed line) and to the gaussian density blob (dotted line). Bottom: coronal density distribution n_e,cor along the LOS (solid line) and total density distributions for the cases A (dashed blue line) and B (dotted red line).