Include GNSS data into recordings

Software
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Hello all,

I am using an OS2 to collect point clouds from roads and streets.

Right now, I manually align the point cloud with a geo-referenced map, but this process is slow and results in really bad precision.

I have a GPS/RTC receiver connected through the multiport IO + pulse sync and I can sucessfully read the NMEA sentences via the ouster API, including all the “locked” status mentioned in the end of this post.

My question is: is it possible to include the GPS data from the receiver in the recorded PCAP file or ROS bags? Ideally, I’d like to feed a mapping algorithm with point cloud + IMU + GPS data. I am unsure if the NMEA sentence is just used for timestamping or if it can be fully integrated onto the final recording. If it is I don’t see it mentioned in the documentation, only the timestamping part.

As a fallback, I can record the data from the GPS separately and align it with timestamps (since both GPS and OS2 are now synchronized), but this would require some architectural changes and a way to merge both data streams.

TLDR: Can more GPS data be recorded via the PCAP (preferably) or the ROS bag? Currently only the timestamp is exported, but is it possible to also include location or even the full NMEA sentences?

Thank you very much!

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Hi @PRamos,

You should be able to write the additional GPS data to the ROS bag if you directly interface with the GPS.

With regard to retrieving the GPS data directly from the sensor .. This is something that needs to be supported by the FW, I would check the next FW release for this feature.

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Ok, thank you for confirming it!

I will be checking the next FW releases. It would be very useful to have GPS data directly accessible from the sensor and ideally captured in the PCAP file (if that format supports it), as I wouldn’t need to align the GPS + Lidar frames in post-processing.

I can already query the latest NMEA sentence through the API, but it is very slow and inconsistent (HTTP requests add a lot of overhead) so it wouldn’t work on my current system, but this means the NMEA sentence is already temporarily persisted in the lidar.