1. A method comprising: for a wireless communication device having a plurality of antennas, determining a centroid of the plurality of antennas; computing for the centroid a heatmap for a measured parameter across a plurality of bins at coordinates within a region of interest; storing heatmap data for the centroid in memory; for a given one of the plurality of antennas, computing a difference between a heatmap for the given antenna and the heatmap for the centroid; and storing in the memory difference data representing the difference for the given antenna.