Thanks to Mike Rainey AA1TJ for putting me on to this. The Reverse Beacon Network is a revolutionary new idea. Instead of beacons actively transmitting signals, the RBN is a network of stations listening to the bands and reporting what stations they hear, when and how well. It works by using skimmers to check activity and then uploading spots to an internet database much like WSPRnet for WSPR spots. Using it you can see if your signals are making it to a given spotting location.