double elevationFilter(OsmPos n) {
        if (nodesCache != null) {
            final int r = nodesCache.getElevationType(n.getILon(), n.getILat());
            if (r == 1) {
                return -5.;
            }
        }
        return -10.;
    }
find the elevation type for position
to determine the filter value

@param n  the point
@return  the filter value for 1sec / 3sec elevation source
main/src/main/java/cgeo/geocaching/brouter/core/RoutingEngine.java