wsprd - Man Page

is a decoder for K1JT's Weak Signal Propagation Reporter (WSPR) mode.


wsprd [Options] [FILE]


wsprd - The program is written in C and is a command-line program that reads from a .c2 FILE or .wav FILE and writes output to the console. It is used by WSJT-X for wspr-mode decoding.


-a <path>

Path to writeable data files, default="."

-c <file>

Write .c2 file at the end of the first pass

-e x

x is transceiver dial frequency error in Hz

-f x

x is transceiver dial frequency in MHz


do not use, or update the hash table


decode wspr-15 .wav file


quick mode - does not dig deep for weak signals


single pass mode, no subtraction (same as original wsprd)


verbose mode, shows duplicate decodings


wideband mode - decode signals within +/- 150 Hz of center

-z x

x is fano metric table bias, default is 0.42

The FILE can be either .wav or .c2, for example:

./wsprd -wf 14.0956 140709_2258.wav

NOTE for .c2 files, the frequency within the file overrides the command line value.



  1. This program attempts to maximize the number of successful decodes per transmit interval by trying to decode virtually every peak in the averaged spectrum. The program also implements two-pass decoding, whereby signals that are successfully decoded are subtracted one-by-one during the first decoding pass. Then, the decoder is run again. In many cases the subtraction process will uncover signals that can then be successfully decoded on the second pass.
  2. There will be occasional duplicate decodes when two closely spaced peaks come from the same signal. The program removes dupes based on callsign and frequency. Two decodes that have the same callsign and estimated frequencies that are within 1 Hz will be treated as decodes of the same signal. This dupechecking is turned off with the -v flag.


Joe Taylor, K1JT and Steven Franks, K9AN


WSPRD is Copyright © 2015 by Joseph H. Taylor, Jr., K1JT, and Steven Franke, K9AN, with contributions from additional authors. WSPRD is Open Source software, licensed under the GNU General Public License (GPLv3).

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.


02/03/2021 AsciiDoc 2.3.0 WSPRD Manual