In theory, a dual antenna receiver can output a heading direction. Can this unit output a heading?
There is an NMEA-0183 message associated with the heading. Here is an example:
$GPHDT,123.456,T*00
Thanks,
Yes, the ZED-F9P provides heading information.
Hi Sparky,
Is there somewhere that’s documented? I have not been able to find it.
Thanks,
David
Oops. Never mind. Got it out of the data ZED sheet. Thanks again.
Dear Sparky,
This board has a single antenna with a splitter to the ZED and NEO chips. Sorry for the stupid question, but how does it determine a valid non-zero heading from one antenna? I’m reading about the HPS profiles that use the inertial sensors in the ZED. But suppose you have an essentially static box, i.e. all it does is rotate. The integration manual says that IMU heading is frozen when the vehicle is stopped. How will it know which direction it’s pointing?
Or am I missing something?
Thanks Again,
David
You’d need a dual ZED-F9P implementation (Moving Base in u-blox speak) to support two antennas
The NEO-D9S in the GPS-22560 is an L-Band modem to demodulate signals from Inmarsat, etc, used by providers like Sapcorda (PointPerfect), Trimble, etc
The ZED-F9P decrypts the SPARTN data forms, and provides position.
With this board you’d need to be moving. Direction of travel reported by RMC, UBX-NAV-PVT, etc.
https://www.sparkfun.com/products/22560 (ZED-F9P + NEO-D9S)
You’d need a product with a ZED-F9R to have an integrated IMU. That wouldn’t preclude you from implementing your own INS / AHRS with the GPS-22560
Hey Clive,
I’m looking at the F9R manuals, so I’m probably more confused that I think…
I suppose the simplest thing would be to use two boards and do the math on the host. Adds some cost to the system tho. I was hoping to get away with just one board.
Cheers!
D
Putting two ZED-F9P on a board is rather costly, and has fewer customers. Most just daisy-chain a pair of boards, like the GPS-16481 https://www.sparkfun.com/products/16481
https://portal.u-blox.com/s/question/0D … s-accuracy
https://portal.u-blox.com/s/question/0D … nformation
You could combine a GPS-22560 and GPS-16481 such that one reports position (RTK via RTCM3 or SPARTN), and the other relative displacement / angle
I don’t understand the picture. Is that green thing just an antenna, or some other board feeding the two F9P boards?
The green thing represents a RTCM3 radio link to the fixed base station via a serial input
Moving Base App Note
Makes sense. Does the F9P support some sort of serial pass-through mode that allows it to share the RTCM source?
No, one would typically just use wire for such a task.
In moving base the Primary unit is generating RTCM3 data it feeds to the Secondary Unit. Where the Secondary unit is performing an RTK solution with a base line of a few carrier cycles. Nominally about 1m separation in the two antennas to resolve the angle sub-degree.
The Primary unit is fed with RTCM3 or SPARTN data so as to resolve it’s position with high accuracy.
Thanks for the App Note.
Presumably the primary correction data could be coming over a PerfectPoint L-Band link to a NEO-D9S then on to the F9R via UART?
The ZED-F9R is the IMU model, it can’t be used in the dual antenna configuration. For RTK operation it is fed with RTCM3 from a base, or SPARTN from a NEO-D9S, or network connection.
The ZED-F9P can take similar data to establish it’s position
The pairing works with ZED-F9P + F9P or F9H models.
The ZED-F9R can’t generate RTCM3 output
If a receiver is moving it can provide speed and trajectory
Copy. I will concentrate on the F9P.
Clive,
BTW, is there a selection matrix that shows the major differences between the various chips (E9R, E9H, E9P, E9K, E9T, -0x, etc)?
Thanks,
David