Hi, I’m trying to determine whether the subject product can meet my needs as a flight track recorder. I’m hoping for 10 to 20 Hz recording, and the ublox “navigation rate” and accuracy listed more than meets my needs. What I’m unsure about is whether this recording rate can be achieved using the SD card. The Hookup Guide says “Logging any of 67 messages at up to 4Hz is supported for all constellations.”. Does this imply that I can only record the GPS solution at that rate, and not at the 10 or 20 Hz I’m looking for?
RTK Express Plus is using a UBlox F9R chip that can produce up to 30 Hz messages in priority navigation mode. In this mode, only a fraction of messages can be produced at this rate. Priority mode also needs the use of the fusion engine (combining RTK and IMU). Fusion engine is only available specific dynamics : automotive, e-bike and mower. So, you will not be able to use it for flight tracking. You will have better to go F9P (with RTK Express for instance) for high rate RTK. Or you may go to other products using Unicore UM980/981/982.
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@Eric_S Thank you for the information! Are you saying the RTK Express with the F9P chip is capable of logging at a higher rate? I see its Hookup Guide has the same comment about 4 Hz. And I will look into the Unicore options you suggest. Thanks!
The data sheet for the ZED-F9P goes into the specifics of the RTK solution rates vs constellation combinations. I think it’s quoted as around 7 Hz for all, figure 30+ satellites contributing.
The RAW MEASUREMENT rates can be significantly higher, but you need to decimate the SOLUTION RATE to reflect the computational load doing so creates.
The ZED-F9R has a lower RTK rate, originally around 2 Hz, but now 4-5 Hz, which it uses to establish hard way points on the track of the vehicle, and then the 100 Hz IMU rates are used to fill in the gaps via dead-reckoning to get the quoted 30 Hz PRIORITY SOLUTION RATES, or HNR (HIGH NAVIGATION RATE) on prior M8L, M8U, M8V implementations.
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