This article is a compendium of articles on how to QC a base station observation file. This is required when we detect a problem with the base station observation during trajectory processing.
| Note: If you encounter an issue with trajectory processing, start by checking whether the problem is related to the observation or the GNSS/Inertial file. Check the log file and process the trajectory in QC-Only (Realtime). |
Check the RINEX file
It is possible to review the settings of the observation file just by reading the header of the RINEX file.
Minimum Recommendations for Base Observation FilesTo ensure reliable and accurate processing, base GNSS observation files should meet the following minimum criteria:
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- Open the RINEX file with notepad or similar.
- Check the header.
3.04 OBSERVATION DATA M (MIXED) RINEX VERSION / TYPE
TERSUS TERSUS 2023-09-14 08:54 PGM / RUN BY / DATE
52004199 MARKER NAME
52004199 MARKER NUMBER
TERSUS TERSUS OBSERVER / AGENCY
BX40C REC # / TYPE / VERS
TRSOSCAREU NONE ANT # / TYPE
3962035.5018 -94275.8454 4980798.6595 APPROX POSITION XYZ
1.6830 0.0000 0.0000 ANTENNA: DELTA H/E/N
1.000 INTERVAL
G 12 C1C L1C D1C S1C C2W L2W D2W S2W C5Q L5Q D5Q S5Q SYS / # / OBS TYPES
R 8 C1C L1C D1C S1C C2C L2C D2C S2C SYS / # / OBS TYPES
C 12 C1I L1I D1I S1I C7I L7I D7I S7I C6I L6I D6I S6I SYS / # / OBS TYPES
E 12 C1B L1B D1B S1B C7Q L7Q D7Q S7Q C5Q L5Q D5Q S5Q SYS / # / OBS TYPES
J 12 C1C L1C D1C S1C C2W L2W D2W S2W C5Q L5Q D5Q S5Q SYS / # / OBS TYPES
S 4 C1C L1C D1C S1C SYS / # / OBS TYPES
2023 9 14 8 54 23.0000000 GPS TIME OF FIRST OBS
2023 9 14 8 54 44.0000000 GPS TIME OF LAST OBS
18 LEAP SECONDS
C1C 0.000 C1P 0.000 C2C 0.000 C2P 0.000 GLONASS COD/PHS/BIS
END OF HEADER - RINEX version: 3.04, recommended to work in the latest version 3.04
- Constellations: M (MIXED), multiple constellations were stored
3.04 OBSERVATION DATA M (MIXED) RINEX VERSION / TYPE- Recording interval: 1.000, it is recording an observation every second i.e., 1hz.
1.000 INTERVAL - Constellations recorded: G (GPS), R (GLONASS), E (Galileo), C (BeiDou), J (QZSS) and S (SBAS). Recommended to work at least with GPS, GLONASS, Galileo and BeiDou.
G 12 C1C L1C D1C S1C C2W L2W D2W S2W C5Q L5Q D5Q S5Q SYS / # / OBS TYPES
R 8 C1C L1C D1C S1C C2C L2C D2C S2C SYS / # / OBS TYPES
C 12 C1I L1I D1I S1I C7I L7I D7I S7I C6I L6I D6I S6I SYS / # / OBS TYPES
E 12 C1B L1B D1B S1B C7Q L7Q D7Q S7Q C5Q L5Q D5Q S5Q SYS / # / OBS TYPES
J 12 C1C L1C D1C S1C C2W L2W D2W S2W C5Q L5Q D5Q S5Q SYS / # / OBS TYPES
S 4 C1C L1C D1C S1C SYS / # / OBS TYPES - Static recording: Not conclusive, but usually if we see a marker name and a single approx. position means static.
52004199 MARKER NAME
52004199 MARKER NUMBER
...
3962035.5018 -94275.8454 4980798.6595 APPROX POSITION XYZ - Antenna model (optional): Knowing the antenna model is important for applying the antenna calibration values. Learn more about Troubleshooting a Missing Antenna Calibration.
BX40C REC # / TYPE / VERS
TRSOSCAREU NONE ANT # / TYPE - Leap second (optional): The known difference between the GNSS time and UTC time. Learn more about Resolving POSPac GNSS Import Error: Missing Leap Second Information
18 LEAP SECONDS- Start/End time: Check the starting & ending time. It should cover the full cycle.
2023 9 14 8 54 23.0000000 GPS TIME OF FIRST OBS
2023 9 14 8 54 44.0000000 GPS TIME OF LAST OBS Convert the Observation File Format
If the observation file is not in RINEX or Trimble T02, convert it to RINEX.
Learn more about converting Leica base observation files to RINEX
Learn more about converting Topcon base observation files to RINEX
Check the Observation File for Gaps
Check if the observation file has any gap.
Learn more about Checking for Gaps in Base Station Observation Files
If it has gaps, it can be trimmed.
Learn how to trim a RINEX file with RTKLib
Alternatives to Single Base Proessing
If your GNSS base station data is unavailable or unreliable, you can still achieve accurate positioning using Trimble’s PP-RTX (Post-Processed Real-Time Extended) technology for supported systems. This cloud-based correction service allows you to post process the sensor trajectory without relying on a local base station.
Learn What to Do If You Have a Problem with Your Base Station
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