Here4/PRO height difference with Here3

Hello from Italy!

I am experiencing a strange issue with the Here4/PRO GPS compared to the Here3, which I hope some kind soul could help me with.

I connected both the Here3 and Here4 to a CubeBlack with the latest vanilla ArduPilot firmware 4.4.4, and the firmware for Here4 is also up to date. Below is a screenshot of the messages:

#15 is Here4, #125 is Here3. The correct heights are from #125, ~28000 MSL and ~73000 WGS.
What seems strange to me is that both the ellipsoid and MSL heights of #15 are exactly the same, which doesn’t seem right.

Can someone suggest a potential solution? I use the ellipsoid data in my application for backward compatibility, so I cannot switch to using MSL.
I am experiencing the same behavior with all three of my Here4 units, as well as with the HerePRO.

Thanks in advance

Hi Ivan, thanks for reporting. I will look into fixing that.

1 Like

Hi @sidbh, do you have any news for us about this? Thx!

Hi @Ivan apologies for the delay, I have created a new release: Release v1.13.3 · CubePilot/GNSSPeriph-release · GitHub The ellipsoid height should be correctly set now. Please verify. Use the Here4_FW.bin and HerePro_FW.bin from to update the GPS modules. I will make this as official release after few more tests and positive result on your end.

Hi @sidbh, thanks for replying back. We’re testing this out on the ground and on a few flights this week. I’ll make sure to give you some good feedback soon

we are testing our fleet with here4 modules and the height estimations are very accurate compared with here3/3+