Hi, I need to perform post-processed kinematic (PPK) analysis. How can I record the raw GNSS data (observation and ephemeris) from my K803 module to my computer?
Hi,
Recording raw data is essential for high-precision post-processing. You can achieve this by sending specific LOG commands via a serial port.
Note: Replace comX with your actual output port
log comX rawephemb onchanged // GPS Ephemeris
log comX glorawephemb onchanged // GLONASS Ephemeris
log comX bd2rawephemb onchanged // BeiDou Ephemeris
log comX galephemerisb onchanged // Galileo Ephemeris
log comX rangecmpb ontime 1 // Observation Data (1Hz)
Important Steps:
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Preparation: Ensure your module is connected to a GNSS antenna with a clear sky view.
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File Logging: Before sending these commands, make sure your serial tool (like CRU or Terminal) is set to "save" or "Capture Text" mode to save the binary stream.
Thanks! The data is logging now. However, I noticed the file size grows very quickly. Are there any tips to ensure I don't lose data during long observation sessions, and what should I do with the output file next?
That’s a great observation. Raw GNSS data can be quite dense, especially with multi-constellation support. Here are some professional tips for managing your logs:
1. Managing File Integrity:
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Baud Rate: Since rangecmpb (compressed range) and multiple ephemeris logs generate high traffic, ensure your serial port baud rate is set to 460800 to prevent data "choking."
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Binary Format: The commands above output in Binary (indicated by the 'b' at the end of the command). Binary is much more efficient than ASCII for long-term logging.
2. Post-Processing Workflow:
