We an issue we’ve been experiencing with the HERE 4 units we’ve been using.
So far, we’ve purchased a total of 75 units trough resellers in Germany and Spain. During testing, we’ve noticed a recurring issue: some GPS units never achieve RTK fix, even when placed in identical conditions to others that do. This includes the same location, antenna, power supply, and setup—everything controlled and replicated.
Out of the 75 units, only 36 are consistently delivering reliable RTK performance. The rest either perform poorly or never reach a fix at all.
We’ve documented and recorded all test data, including logs, photos, and videos, and would be more than happy to share this with you if it helps in diagnosing the problem.
We’re hoping to work with you to find a solution to this issue, as it’s creating serious delays in our workflow.
We are a drone manufacturer, and we require a great number of GPS units, but working within specs.
We need urgent help with this issue.
Looking forward to your response.
Đani Vrsalović
Have you tried metering the power on each faulty unit?
Yes, the first thing we did. Tested on Lab power sources, they all have the same values.
They were interchanged between the drones that had a good GPS signals and the ones. It was the same even when its installed on the different drone, so that is not the problem for sure.
Please measure the noise on the vehicle power supply and the electrical noise in the area around the receiver.
Put each of the suspect receivers in an open area with a quiet power supply and record the signal and noise levels.
If you provide a log I’m quite certain you will see the receiver is happily reporting a serious noise issue in the installation.
The here 4 has an inbuilt spectrum analyser that is very helpful in tracking down these sorts of issues.