Most of the major radio astronomy observatories maintain archives (e.g., [0]). Of course, they mostly use highly directional dishes pointed at the sky, but loca

Most of the major radio astronomy observatories maintain archives (e.g., [0]). Of course, they mostly use highly directional dishes pointed at the sky, but local radio signals can create interference[1]. So, those archives provide some probe/record of terrestrial RF spectrum. Of course, those telescopes are generally placed in radio-quiet locations. [0] https://archive.nrao.edu/archive/advquery.jsp https://archive.nrao.edu/archive/advquery.jsp [1] http://www.gb.nrao.edu/IPG/ http://www.gb.nrao.edu/IPG/