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WSPR (pronounced "whisper") stands for "Weak Signal Propagation Reporter". It is a computer program used for weak-signal radio communication between amateur radio operators. The program was initially written by Joe Taylor, K1JT, but is now open source and is developed by a small team. The program is designed for sending and receiving low-power transmissions to test propagation paths on the MF and HF bands. WSPR implements a protocol designed for probing potential propagation paths with low-power transmissions. Transmissions carry a station's callsign, Maidenhead grid locator, and transmitter power in dBm. The program can decode signals with S/N as low as -28 dB in a 2500 Hz bandwidth. Stations with internet access can automatically upload their reception reports to a central database called WSPRnet, which includes a mapping facility. == The WSPR Protocol== The type of radio emission is "F1D", frequency-shift keying. A message contains a station's callsign, Maidenhead grid locator, and transmitter power in dBm.〔Joe Taylor, K1JT: WSPRing Around the World. QST November (2010), p. 30-32.〕 The WSPR protocol compresses the information in the message into 50 binary digits. These are encoded using a convolutional code with constraint length K=32 and a rate of r=1/2.〔〔G4JNT: The WSPR Coding Process: Non-normative specification of WSPR protocol http://www.g4jnt.com/Coding/WSPR_Coding_Process.pdf〕 The long constraint length makes undetected decoding errors less probable at the cost, that the highly efficient Viterbi algorithm must be replaced by a simple sequential algorithm for the decoding process.〔 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「WSPR (amateur radio software)」の詳細全文を読む スポンサード リンク
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