'\" t
.\"     Title: gpssubframe
.\"    Author: [see the "AUTHOR" section]
.\" Generator: DocBook XSL Stylesheets vsnapshot <http://docbook.sf.net/>
.\"      Date: 6 December 2020
.\"    Manual: GPSD Documentation
.\"    Source: The GPSD Project
.\"  Language: English
.\"
.TH "GPSSUBFRAME" "1" "6 December 2020" "The GPSD Project" "GPSD Documentation"
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.SH "NAME"
gpssubframe \- tool to dump subframe sentences from gpsd
.SH "SYNOPSIS"
.HP \w'\fBgpssubframe\fR\ 'u
\fBgpssubframe\fR [\-?] [\-\-count\ \fICOUNT\fR] [\-\-debug\ \fILVL\fR] [\-\-desc] [\-\-device\ \fIDEVICE\fR] [\-\-file\ \fIFILE\fR] [\-\-help] [\-\-host\ \fIHOST\fR] [\-\-load\ \fIFILE\fR] [\-\-port\ \fIPORT\fR] [\-\-progress] [\-\-satpos] [\-\-save\ \fIFILE\fR] [\-\-seconds\ \fISECONDS\fR] [\-\-test] [\-\-time\ \fISECONDS\fR] [\-\-version] [\-D\ \fILVL\fR] [\-f\ \fIFILE\fR] [\-h] [\-n\ \fICOUNT\fR] [\-V] [\-x\ \fISECONDS\fR] [\fIserver\fR [\fI:port\fR [\fI:device\fR]]]
.SH "DESCRIPTION"
.PP
gpssubframe
is a tool to connect to
gpsd
and dump decoded subframe data to stdout\&. This is only useful if your GNSS receiver can output GPS subframe messages, and is configured to do so\&. A working knowledge of IS\-GPS\-200 is also required\&. Keep your copy close at hand\&.
.PP
gpssubframe
does not require root privileges, and can be run concurrently with other tools connecting to the local
gpsd
without causing problems\&.
.PP
The program will accumulate subframe message and output them by GPS satellite number on exit\&. By default the program never exits unless the user selects the number of seconds to run or number of messages to capture\&.
.PP
By default
gpssubframe
connects to a
gpsd
running on the local host\&. Optionally a host, TCP/IP port number and remote device can be given\&.
.SH "OPTIONS"
.PP
\fB\-?\fR, \fB\-h\fR, \fB\-\-help\fR
.RS 4
\-Print a usage message and exit\&.
.RE
.PP
\fB\-c COUNT\fR, \fB\-\-count COUNT\fR
.RS 4
Exit after COUNT subframe messages\&.
.RE
.PP
\fB\-\-device DEVICE\fR
.RS 4
Connect to device DEVICE on gpsd host\&.
.RE
.PP
\fB\-D LVL\fR, \fB\-\-debug LVL\fR
.RS 4
Set debug level to LVL\&.
.RE
.PP
\fB\-\-file FILE\fR
.RS 4
Read JSON from FILE instead of from gpsd\&.\&.
.RE
.PP
\fB\-\-host HOST\fR
.RS 4
Connect to gpsd on host HOST\&.
.RE
.PP
\fB\-\-port PORT\fR
.RS 4
Connect to gpsd on port PORT\&.
.RE
.PP
\fB\-\-progress\fR
.RS 4
Print progress reports as messages are received\&.
.RE
.PP
\fB\-\-satpos\fR
.RS 4
Compute GPS satellite positions before exit\&.
.RE
.PP
\fB\-\-time SEC\fR
.RS 4
Compute satellite position at time SEC in POSIX seconds\&.
.RE
.PP
\fB\-\-test\fR
.RS 4
Run
\fB\-\-satpos\fR
selftest code\&.
.RE
.PP
\fB\-V\fR, \fB\-\-version\fR
.RS 4
Print the program version, then exit\&.
.RE
.PP
\fB\-x SEC\fR, \fB\-\-seconds SEC\fR
.RS 4
Seconds of messages to parse\&. 0 to disable\&.
.RE
.SH "EXAMPLES"
.PP
First connfigure a u\-blox 9\-series to output subframe messages\&. Then have
gpssubframe
gather one complete set of subframes, then print the data organized by GPS satellite number\&. Then calculate and print the known satellite positions as well as the azimuth, elevation, and range from the current position:
.sp
.if n \{\
.RS 4
.\}
.nf
ubxtool \-P 22 \-e SFRBX
gpssubframe \-x 750 \-\-satpos
   
.fi
.if n \{\
.RE
.\}
.PP
If staring at a blank screen for 12\&.5 minutes is too stressful, then enable progress messages:
.sp
.if n \{\
.RS 4
.\}
.nf
gpssubframe \-x 750 \-\-satpos \-\-progress
   
.fi
.if n \{\
.RE
.\}
.sp
.SH "SEE ALSO"
.PP
\fBgpsd\fR(8),
\fBgps\fR(1),
\fBgpsprof\fR(1),
\fBgpsfake\fR(1),
\fBgpsctl\fR(1),
\fBgpscat\fR(1)\&.
.PP
IS\-GPS\-200 "NAVSTAR GPS Space Segment/Navigation User Segment Interfaces"
.SH "AUTHOR"
.PP
Gary E\&. Miller
<gem@rellim\&.com>\&.