Relevance

The algorithm so far will generate an interpolated quality for each point. It is easy to see, that there will be points for which no statement can be made. Therefore, the third step introduces relevance, calculated for each point, to make this difference visible. In the properties window, you can set a "RelevanceDistance", which states the range, in meters, around a measurement where relevance will be one. For mere elegancy, relevance will not fall to zero immediately, but descend slowly, causing a fade-out in color.

A recommended setting in a well-calibrated map is $4$ ($\pm0.5$).