If I wanted to plot a Radio Contour Map what type of information would I need. I have a Garmin eTrex Legend which can provide longitude and latitude (position data) and I have a portable Spectrum Analyzer. What I want is to generate a color-graded map will show which geographical regions of some location, based on the location of hills, mountains and other topographical features, currently have high or low radio signal coverage. What information should I be getting from the spectrum analyzer? Power Spectrum Density? Or is it average power over some frequency band? I think its the latter.