RECALL THE THEORETICAL JARGON:
•
•
•
•
•
•
•
•
L1 pseudorange – C/A or P(Y)
L2 pseudorange - P(Y) or C2
L5 pseudorange - ignore for now.
L1 Phase
L2 Phase (can come from either P(Y) or C2 stream)
L5 Phase - ignore
Doppler - ignore!
Signal to noise ratio (SNR)
1
NOW YOU NEED TO KNOW THE RINEX
JARGON
•
•
•
•
•
•
•
L1 pseudorange – C/A = C1
L1 pseudorange – P(Y) = P1
L2 pseudorange - P(Y) = P2
L2 pseudorange - C = C2
L1 Phase = L1
L2 Phase =L2
Signal to noise ratio (SNR) = S1 and S2
Note L1 and L2 are really the names of the GPS frequencies.
But RINEX uses the same names for the phase data. This is really
unfortunate - but it is the way it is.
2
RINEX FILES
RINEX is a generic term - it refers to a kind of data format.
It is ALWAYS ascii. (BINEX is a binary version).
o: Observation
d: Observation (compressed or Hatanaka)
n: Navigation file
m: Meteorological data file
g: GLONASS Navigation file
h: Geostationary GPS payload nav mess file
b: Geostationary GPS payload broadcast
data
c: Clock files
3
http://igscb.jpl.nasa.gov/igscb/data/format/rinex210.txt
RINEX observation file
o is the standard observation file
d is the compressed observation file
Many people call the d file Hatanaka format after Yuki
Hatanaka who defined it. You need an extra program to
convert compressed to normal observation file. See this
link for more details
http://www.gsi.go.jp/common/000045517.pdf
4
Every RINEX file has a header - they are important!
Every RINEX file has a header
2.11
teqc
OBSERVATION DATA
G (GPS)
RINEX VERSION / TYPE
2012Jun6
gpsops
20120921 00:08:49UTCPGM / RUN BY / DATE
30.0000
INTERVAL
1
1
WAVELENGTH FACT L1/2
7
L1
L2
P1
P2
C1
S1
S2
# / TYPES OF OBSERV
Linux 2.4.21-27.ELsmp|Opteron|gcc -static|Linux x86_64|=+
COMMENT
2.10
OBSERVATION DATA
GPS
COMMENT
soc2rnx ver 1.20
gpsops
21-Sep-2012 00:08:49COMMENT
S1, if present, is the SNR for the C/A data stream on L1.
COMMENT
SNR is mapped to RINEX snr flag value [1,4-9]
COMMENT
SNR:
>316 >100 >31.6 >10 >3.2
>0 bad=0
COMMENT
L1 & L2:
9
8
7
6
5
4
1
COMMENT
GGN
USNO
OBSERVER / AGENCY
KW-0201
AOAD/M_T
NONE
ANT # / TYPE
-1248596.2520 -4819428.2840 3976506.0340
APPROX POSITION XYZ
0.0000
0.0000
0.0000
ANTENNA: DELTA H/E/N
RT920013101
ASHTECH Z-XII3T
IL01-1D04-MCF-12MX REC # / TYPE / VERS
AMC2
MARKER NAME
40472S004
MARKER NUMBER
There are rules for how these files are written and read. Useful to know that this
format (and these rules) are defined by people that use Fortran.
5
Every RINEX file has a header - they are important!
2.11
teqc
OBSERVATION DATA
G (GPS)
RINEX VERSION / TYPE
2012Jun6
gpsops
20120921 00:08:49UTCPGM / RUN BY / DATE
30.0000
INTERVAL
1
1
WAVELENGTH FACT L1/2
7
L1
L2
P1
P2
C1
S1
S2
# / TYPES OF OBSERV
Linux 2.4.21-27.ELsmp|Opteron|gcc -static|Linux x86_64|=+
COMMENT
2.10
OBSERVATION DATA
GPS
COMMENT
soc2rnx ver 1.20
gpsops
21-Sep-2012 00:08:49COMMENT
S1, if present, is the SNR for the C/A data stream on L1.
COMMENT
SNR is mapped to RINEX snr flag value [1,4-9]
COMMENT
SNR:
>316 >100 >31.6 >10 >3.2
>0 bad=0
COMMENT
L1 & L2:
9
8
7
6
5
4
1
COMMENT
GGN
USNO
OBSERVER / AGENCY
KW-0201
AOAD/M_T
NONE
ANT # / TYPE
-1248596.2520 -4819428.2840 3976506.0340
APPROX POSITION XYZ
0.0000
0.0000
0.0000
ANTENNA: DELTA H/E/N
RT920013101
ASHTECH Z-XII3T
IL01-1D04-MCF-12MX REC # / TYPE / VERS
AMC2
MARKER NAME
40472S004
MARKER NUMBER
If you are making RINEX files, it is very impolite to leave out the receiver position.
For completeness, always include S1 and S2 (many geodesists leave it out - for no
good reason).
6
Every RINEX file has a header - they are important!
2.11
teqc
OBSERVATION DATA
G (GPS)
RINEX VERSION / TYPE
2012Jun6
gpsops
20120921 00:08:49UTCPGM / RUN BY / DATE
30.0000
INTERVAL
1
1
WAVELENGTH FACT L1/2
7
L1
L2
P1
P2
C1
S1
S2
# / TYPES OF OBSERV
Linux 2.4.21-27.ELsmp|Opteron|gcc -static|Linux x86_64|=+
COMMENT
2.10
OBSERVATION DATA
GPS
COMMENT
soc2rnx ver 1.20
gpsops
21-Sep-2012 00:08:49COMMENT
S1, if present, is the SNR for the C/A data stream on L1.
COMMENT
SNR is mapped to RINEX snr flag value [1,4-9]
COMMENT
SNR:
>316 >100 >31.6 >10 >3.2
>0 bad=0
COMMENT
L1 & L2:
9
8
7
6
5
4
1
COMMENT
GGN
USNO
OBSERVER / AGENCY
KW-0201
AOAD/M_T
NONE
ANT # / TYPE
-1248596.2520 -4819428.2840 3976506.0340
APPROX POSITION XYZ
0.0000
0.0000
0.0000
ANTENNA: DELTA H/E/N
RT920013101
ASHTECH Z-XII3T
IL01-1D04-MCF-12MX REC # / TYPE / VERS
AMC2
MARKER NAME
40472S004
MARKER NUMBER
This means there will be 7 columns of observations, L1 (phase) in the first
column, L2 phase in the second, and so on. Since only 5 columns can fit
in a line, they have to write the 6th and 7th column on the next line.
Rows are saved for satellites. An example on the next page.
7
top line is year, month, day, hour, minute, second
Then number of satellites and their names. G means GPS, R is glonass,
and M is Galileo. If there a blank instead of a letter, it means it is a GPS
satellite. You cannot assume people will use the G - believe me. GPS came
first, so it got to be blank.
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Then number of satellites and their names. G means GPS, R is glonass,
and M is Galileo. If there is no letter, it means it is a GPS satellite.
In this example, there are 9 satellites. They are all GPS satellites.
9
These are the data for PRN 29. Remember the first two columns are
phase (L1 and L2) and then P1, P2, and C1. Last are S1 and S2.
10
What are the units? Don’t guess - Look it up!
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12
What does F14.3 mean?
L1
L2
P1
P2
C1
What is P2?
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RINEX Nav Message – clock model
+----------------------------------------------------------------------------+
|
TABLE A4
|
|
NAVIGATION MESSAGE FILE - DATA RECORD DESCRIPTION
|
+--------------------+------------------------------------------+------------+
|
OBS. RECORD
| DESCRIPTION
|
FORMAT
|
+--------------------+------------------------------------------+------------+
|PRN / EPOCH / SV CLK| - Satellite PRN number
|
I2,
|
|
| - Epoch: Toc - Time of Clock
|
|
|
|
year
(2 digits)
|
5I3,
|
|
|
month
|
|
|
|
day
|
|
|
|
hour
|
|
|
|
minute
|
|
|
|
second
|
F5.1,
|
|
| - SV clock bias
(seconds)
| 3D19.12
|
|
| - SV clock drift
(sec/sec)
|
|
|
| - SV clock drift rate (sec/sec2)
|
|
+--------------------+------------------------------------------+------------+
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RINEX Nav file
the header is boring
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RINEX Nav file
The rest of the numbers refer to Keplerian elements - (not needed yet)
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Where to get RINEX observation data?
In Europe, I prefer EUREF
http://www.epncb.oma.be
In the US, UNAVCO
http://facility.unavco.org/data/dai2/app/dai2.html#
or
CDDIS
http://cddis.nasa.gov
It can be frustrating to find data that are not archived in these larger data centers.
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Where to get RINEX navigation data?
I only use navigation quality orbits for my current research,
and for years I have gotten these files at SOPAC at garner.ucsd.edu
%!/bin/csh
ftp -in garner.ucsd.edu << eofuser anonymous
kristine@valdemar.colorado.govbinarycd pub/rinex/${year}/${day}mget
auto*quiteof
where year is, e.g. 2013, day is day of year, 305
It returns auto3050.13.Z, which is unix compressed, so you need to say
uncompress auto3050.13.Z
There is a smarter command (wget) to pick up files, but I will leave that for
you to figure out!
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There are lots of places to find precise orbits. Just google IGS precise orbits and
you will find a link to somewhere. They DO NOT use RINEX. They have
their own format, which is called sp3.
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