mirror of
https://github.com/saitohirga/WSJT-X.git
synced 2024-11-18 10:01:57 -05:00
71 lines
3.2 KiB
Plaintext
Executable File
71 lines
3.2 KiB
Plaintext
Executable File
wsprd is a decoder for K1JT's Weak Signal Propagation Reporter (WSPR) mode.
|
|
|
|
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.
|
|
|
|
USAGE:
|
|
wsprd [options...] infile
|
|
|
|
OPTIONS:
|
|
-a <path> path to writeable data files, default="."
|
|
-B disable block demodulation - use single-symbol noncoherent demod
|
|
-c write .c2 file at the end of the first pass
|
|
-C maximum number of decoder cycles per bit, default 10000
|
|
-d deeper search. Slower, a few more decodes
|
|
-e x (x is transceiver dial frequency error in Hz)
|
|
-f x (x is transceiver dial frequency in MHz)
|
|
-H do not use (or update) the hash table
|
|
-J use the stack decoder instead of Fano decoder
|
|
-m decode wspr-15 .wav file
|
|
-o n (0<=n<=5), decoding depth for OSD, default is disabled
|
|
-q quick mode - doesn't dig deep for weak signals
|
|
-s single pass mode, no subtraction (same as original wsprd)
|
|
-v verbose mode (shows dupes)
|
|
-w wideband mode - decode signals within +/- 150 Hz of center
|
|
-z x (x is fano metric table bias, default is 0.45)
|
|
|
|
infile can be either .wav or .c2
|
|
|
|
e.g.
|
|
./wsprd -wf 14.0956 140709_2258.wav
|
|
|
|
Note that for .c2 files, the frequency within the file overrides the command
|
|
line value.
|
|
|
|
FEATURES:
|
|
By default, wsprd reports signals that are within +/- 110 Hz of the
|
|
subband center frequency. The wideband option (-w) extends this to +/- 150 Hz.
|
|
|
|
wsprd maintains a hashtable and will decode all three types of wspr
|
|
messages. An option (-H) is available to turn off use of the hashtable.
|
|
|
|
Decoding is attempted using soft symbols derived using single-symbol
|
|
noncoherent detection. If decoding fails, then soft symbols derived using
|
|
block demodulation over 2- and 3-symbol blocks are used in subsequent
|
|
decoding attempts. For slower computers, block demodulation can be
|
|
disabled with the -B command line option.
|
|
|
|
The symbols are decoded using Phil Karn's sequential decoder routine,
|
|
fano.c. The -J option replaces the Fano algorithm with the Jelinek
|
|
"stack-bucket" algorithm. If the -o command line option is enabled, then
|
|
an ordered-statistics decoder (OSD) is invoked if the Fano (or Jelinek) algorithm
|
|
fails. The OSD is a complete decoder, meaning that it always returns a codeword.
|
|
A returned codeword is considered valid only if the unpacked decode contains
|
|
a callsign that is already in the hashtable.
|
|
|
|
NOTES:
|
|
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.
|
|
|
|
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.
|
|
|