.

Sergio, what exactly do you mean by "measurement" or "quantification" in this context ?

(or what do you expect from or plan to do with your sammon mapping ?)

.

Sammon Mapping, by it's nature, loses information in the transformation from a high-dimensional space to the 2D space of the map. It is therefore doubtful you can use it in any quantitative way.

If you are using it in conjunction with a Self-Organizing Map, you can of course quantify the distances between the map cell vectors mi using a distance metric of your choice.