WSPR

 

https://3fs.net.au/vhf/wspr/

WSPR (Weak Signal Propagation Reporter) is a digital mode for amateur radio communications. It was developed by Joe Taylor, K1JT, and is designed for sending and receiving low-power transmissions to test the propagation of signals on the MF and HF bands. WSPR uses a robust digital mode that can decode signals with a signal-to-noise ratio as low as -28 dB. It operates on a 2-minute cycle, during which a station transmits a brief identification message, including a

call sign, grid locator, and power level. The received reports are then uploaded to a central database where they can be used to track signal propagation and study band conditions.