1GPSRINEX(1)                   GPSD Documentation                   GPSRINEX(1)
2
3
4

NAME

6       gpsrinex - Read data from gpsd convert to RINEX3 and save to a file.
7

SYNOPSIS

9       gpsrinex [-D debuglevel] [-f filename] [-h] [-i interval] [-n count]
10                [-V] [server [:port [:device]]]
11

DESCRIPTION

13       gpsrinex is a tool to connect to gpsd and output the received raw
14       measurements as a RINEX 3 observation file. This is useful for sending
15       raw measurements (pseudorange and carrierphase) from gpsd to a Precise
16       Point Positioning (PPP) program or service.
17
18       gpsrinex does not require root privileges, and can be run concurrently
19       with other tools connecting to a local or remote gpsd without causing
20       problems.
21
22       gpsrinex needs the GPS receiver to be sending raw measurements to gpsd.
23       Only a few GPS have this capability. In addition, the gpsd driver for
24       that GPS must support raw mode. Currently only the u-blox driver has
25       this support. Only a few u-blox 8 GPS implment the required
26       UBX-RXM-RAWX message. The NEO-M8T is known to work, but requires
27       configuration with ubxtool.
28
29       RINEX has its own definitions and abbreviations. Be sure to consult
30       their documentation. An observation file (.obs) contains data sets,
31       called epochs, that contain the pseudorange and carrierphase for each
32       satellite seen.
33
34       gpsrinex by default will acquire 20 epochs spaced apart by 30 seconds.
35       That will take 10 minutes to complete. Most users consider the 30
36       second interval to be optimal. Many PPP programs require at least 1 or
37       2 hours data, but no more than 24 or 48 hours of data. Most users
38       consider 4 to 6 hours of data as a minimum for good accuracy.
39       Additional hours will not yield much improvement.
40
41       The output will consist of one RINEX 3 observation file that is ready
42       to be read by your PPP program. The default filename will be in the
43       form: gpsrinexYYYYJJJHHMMSS.obs. You can override this filename with
44       the -f option.
45
46       Optionally a server, TCP/IP port number and remote device can be given.
47       If omitted, gpsrinex connects to localhost on the default port (2947)
48       and watches all devices opened by gpsd.
49

OPTIONS

51       -D [debuglevel] set debug level to [debuglevel].
52
53       -f [filename] save RINEX into [filename].
54
55       -h makes gpsrinex print a usage message and exit.
56
57       -i [interval] wait [interval] seconds between epochs. OPUS accepts
58       intervals of 1, 2, 3, 5, 10, 15 or,30 seconds. OPUS then reduces the
59       data to 30 second intervals. Defeault is 30.
60
61       -n [count] causes [count] epochs to be output. OPUS requires a minimum
62       af 15 minutes, and a maximum of 48 hours, of data.
63
64       -V makes gpsrinex print its version and exit.
65

EXAMPLES

67       Example 1:
68
69       Create a 4 hour .obs file. With a running gpsd accessible on the
70       localhost do all of the following, in order. Order matters.
71
72       The raw measurement messages are long. Be sure your serial port speed
73       is high enough:
74
75           gpsctl -s 115200
76
77       Disable all NMEA messages, and enable binary messages:
78
79           ubxtool -d NMEA
80           ubxtool -e BINARY
81
82       The NEO-M8N will only reliably output raw measurements when only the
83       GPS and QZSS constellations are enabled. If your PPP service can use
84       GLONASS, then enable that as well. Be sure to disable, before enable,
85       so as not to momentarily have too many constellations selected.
86       ubxtool, as recommended by u-blox, enables the QZSS constellation in
87       tandem with GPS. Disable all constellations, except GPS (and QZSS):
88
89           ubxtool -d BEIDOU
90           ubxtool -d GALILEO
91           ubxtool -d GLONASS
92           ubxtool -d SBAS
93           ubxtool -e GPS
94
95       Verify the constellations enabled:
96
97           ubxtool -p CFG-GNSS
98
99       Enable the good stuff, the raw measurement messages:
100
101           ubxtool -e RAWX
102
103       Verify raw data messages are being sent:
104
105           ubxtool | fgrep RAWX
106
107       You should see this output:
108
109           UBX-RXM-RAWX:
110           UBX-RXM-RAWX:
111
112       Collect 4 hours of samples at 30 second intervals, save the RINEX 3
113       observations in the file today.obs:
114
115           gpsrinex -i 30 -n 480 -f today.obs
116
117       Wait 4 hours. Enjoy a meal, or do some exercise. When gpsrinex
118       finishes, upload the file today.obs to your favorite PPP service.
119
120       Example 2:
121
122       Collect raw masurement data from a remote gpsd. The process it later
123       with gpsrinex and gpsprof.
124
125       Ensure the GPS is configured properly, as shown in Example 1.
126
127       Grab 4 hours of raw live data from remote gpsd at 10.168.1.2:
128
129           gpspipe -x 14400 -R 10.168.1.2 > 4h-raw.ubx
130
131       When gpspipe is complete, feed the data to gpsfake:
132
133           gpsfake -1 -P 3000 4h-raw.ubx
134
135       In another window, feed the data to gpsrinex. Use -n 10000000 so that
136       all the data from the raw file is used::
137
138           gpsrinex -i 30 -n 1000000
139
140       Repeat the process with gpsfake to send the data to gpsprof.
141

SEE ALSO

143       One service known to work with obsrinex output is at:
144       https://webapp.geod.nrcan.gc.ca/geod/tools-outils/ppp.php
145
146       OPUS requires 2 frequency observation files.
147       https://www.ngs.noaa.gov/OPUS/
148
149       The curious can find the RINEX 3.03 format described here:
150       ftp://igs.org/pub/data/format/rinex303_update1.pdf
151
152       gpsd(8), gpsfake(1), ubxtool(1).
153

AUTHOR

155       Gary E. Miller <gem@rellim.com>.
156
157
158
159The GPSD Project                  09 Nov 2018                      GPSRINEX(1)