# GPS never published

Source: https://forum.modalai.com/topic/3825/gps-never-published
Category: General Questions (https://forum.modalai.com/category/2/general-questions)
Posted: 2024-09-23 20:15:53 UTC by groupo
Replies: 4 · Views: 898

## groupo · 2024-09-23 20:15:53 UTC

A while ago I posted about having a lower number of satellites in one of my sentinels (7-13) compared to my other one (20). Today the latter sentinel's GPS stopped working. I have clicked through a few forums and tried some qshell commands to no avail. I saw some other posts about the diagnostic work differing with the addition of a 5G modem, which I have. What should I do?

## Reply by groupo · 2024-09-25 20:06:58 UTC

@groupo Any traction?

## Reply by ben grocholsky · 2024-09-26 05:47:11 UTC (in reply to groupo)

@groupo From the description it's hard to tell if the GPS stopped communicating or stopped getting a usable solution. L1 GPS is very easily degraded by RF interference from high speed signals on wires or communications devices. Look at the `jamming_indicator` field in the `sensor_gps` uorb to get a better sense of if you have a RF interference issue. Value much above 40 indicate too much interference. Grounding and shielding the wires from the voxl2 to the GPS can improve this. 

There is a bit more confusion in that px4 health checks by default need > 7 satellites in use to say system has GPS (==> GPS working but not good enough), or EKF2 can reject good GPS and report `no global position` in situations where vibration or magnetic interference is the underlying problem. 

I'd recommend sharing more details from the `sensor_gps` output or a ulg file so folk can help further.

## Reply by Eric Katzfey (ModalAI staff) · 2024-09-26 15:59:51 UTC (in reply to ben grocholsky)

@ben-grocholsky Thanks Ben! Yes, having a look at some log files would definitely help in troubleshooting.

## Reply by groupo · 2024-09-26 17:43:33 UTC (in reply to Eric Katzfey)

Thank you @ben-grocholsky! I should be more clear, when I ran ```px4-listener sensor_gps``` I received something along the lines of "GPS never published". I just went to go get the verbatim output but everything seems to be working. I do indeed see the uorb now. Puzzling