Loading Historical Data - R&S SMW-K44 User Manual

Satellite Navigation

17 Loading Historical Data

The default satellite's constellation and the navigation message are extracted from offi-
cial navigation source files and emulates the GNSS navigation system at 9 February
2016 at 06:00:00 am.
Internal algorithms use the predefined navigation source information and predicts the
satellite's constellation and the navigation messages at any given moment of time. For
most test cases this prediction is sufficient.
When to change the default satellite's constellation and navigation data sour-
ces?
If your test scenario requires realistic GNSS signal or a historical situation has to be
reproduced, you can load constellation and navigation data for any of the GNSS sys-
tems separately.
Loading user-defined constellation is useful, if the HDOP and PDOP values exceed
your specific limits. To observe current values, select "GNSS > Simulation Monitor >
Sky View".
Constellation data and navigation message files formats
Supported are constellation and navigation message files in the following formats:
●
GPS: YUMA, SEM, TXT or RINEX files
See:
–
–
●
GLONASS and QZSS: AGL, YUMA and XML
See
●
Galileo and Beidou: these systems are not yet fully in orbit.
Hence, there are no files available.
●
SBAS: *.ems or *.nstb
See
YUMA, SEM, TXT, XML and AGL files download links
You can download GNSS YUMA, SEM and XML or RINEX files via the Internet. Trans-
fer them to the R&S SMW and load them if required.
Use for example the following sources:
●
US Coast Guard Navigation Center GPS Homepage
http://www.navcen.uscg.gov/?pageName=gpsAlmanacs
Provides YUMA (xxx.alm) and SEM (xxx.al3 files, where xxx denotes the day
of a year
●
http://www.celestrak.com/GPS/almanac/
Provides almanac.sem/yuma.weekXXXX.YYYYYY.txt files, where
xxxx denotes the GPS week and yyyyyy the time of almanac (TOA)
●
ftp://ftp.glonass-iac.ru/MCC/ALMANAC/
User Manual 1178.6379.02 ─ 01
"YUMA, SEM, TXT, XML and AGL files download links"
"RINEX download links"
"YUMA, SEM, TXT, XML and AGL files download links"
"SBAS correction files download links"
on page 191
on page 191
Loading Historical Data
on page 190
on page 190
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