WSPR is a new mode by Joe Taylor, K1JT, introduced in March, 2008. It stands for Weak Signal Propagation Reporting, and it mostly used by a dedicated group of amateurs collecting propagation data.

I maintain the WSPRnet.org site devoted to discussion, operation, and data collection with the WSPR mode. In about 9 months of operation, we have collected information on over 2.5 million spots using this mode.

Full information about all Joe's weak signal modes can be found at the WSJT site.