WSPR-15 is a data telemetry protocol designed for probing potential propagation paths with low-power transmissions. The protocol compresses information using a convolution code with a long constraint length. The long constraint length makes undetected decoding errors less probable, thus allowing receiving stations to decode emissions with signal-to-noise ratios as low as -28 dB in a 2,500 Hz bandwidth.
This experiment will employ a fifteen (15) minute transmit and receive cycle. This slow cycle should improve sensitivity over the traditional two (2) minute WSPR cycle used in the Amateur Radio Service on medium frequency and high frequency bands.
The entire message will consist of the call sign of the station (e.g., WH2XOR, KC4LMD); the Maidenhead grid location of the transmitter (i.e., EN51wn), and the transmitter power, stated in dBm (e.g., 15 dBm).
Carrier frequency will be 137.6 kHz with J7B modulation 1.4648 Hz wide.