GPS lock goes out midflight

Kylen · Sep 18, 2016

Hey all, I am super new to this UAV world, and own a Yuneec Typhoon H (pro) with intel realsense. I have flown it about ten times since i got it a couple weeks ago. The GPS has gone out midflight (in strong wind) 2 times. first time with 14 satellites and second time with 11 satellites.

Since I am pretty new to this, and just dropped 2k of my hard earned money on this bird......when it went into manual mode in strong wind with trees around, I just about had a heart attack. Both times landed fine, but now I am all sketched out about flying it in wind.

Anyway, my real question is, how many satellites do you need to keep a solid GPS lock? I know theres two sets, for the controller and the bird, but whats a good number for both?

The first time could have been a calibration issue, but It happened after 20 minutes of successful flight. Wouldnt a calibration issue show up right away? The second time GPS went out, I had calibrated it the day before just 2 miles away, and flown for 30 minutes at distances of 500m or so, with no issue. Also, each time it goes out mid flight, with pretty much the same number of satellites as when I took off. When I took off the GPS says "ready". I am just confused, so any info helps a lot! Thanks!

banned user · Sep 18, 2016

Kylen said:
Hey all, I am super new to this UAV world, and own a Yuneec Typhoon H (pro) with intel realsense. I have flown it about ten times since i got it a couple weeks ago. The GPS has gone out midflight (in strong wind) 2 times. first time with 14 satellites and second time with 11 satellites.

Since I am pretty new to this, and just dropped 2k of my hard earned money on this bird......when it went into manual mode in strong wind with trees around, I just about had a heart attack. Both times landed fine, but now I am all sketched out about flying it in wind.

Anyway, my real question is, how many satellites do you need to keep a solid GPS lock? I know theres two sets, for the controller and the bird, but whats a good number for both?

The first time could have been a calibration issue, but It happened after 20 minutes of successful flight. Wouldnt a calibration issue show up right away? The second time GPS went out, I had calibrated it the day before just 2 miles away, and flown for 30 minutes at distances of 500m or so, with no issue. Also, each time it goes out mid flight, with pretty much the same number of satellites as when I took off. When I took off the GPS says "ready". I am just confused, so any info helps a lot! Thanks!

GPS should not be turning off mid flight, call Yuneec or your dealer and get it sorted.

For sat visibility my H and ST16 can normally see all of the available sats as per this site..Visibility If you are in the US I don't think you have much GONLASS coverage so you will need to toggle off that switch.

gwhuntoon · Sep 18, 2016

A couple of things - someone here posted this link which shows the best satellite coverage and when for your area Location Lookup and look up a K Index app for your phone which tells you the current Geomagnetic storm rating for your area. I don't fly if its above a 4. Trees and clouds will interfere with satellite reception. I also wait when I start up my H. Even if I have a lot of satellites it doesn't mean I have a good positional lock yet HDOP Acronym for horizontal dilution of precision. A measure of the geometric quality of a GPS satellite configuration in the sky. HDOP is a factor in determining the relative accuracy of a horizontal position. The smaller the DOP number, the better the geometry. It could take from 1-12 minutes to update the satellite almanac assuming the H's GPS does this. If you have a Windows notebook or a Mac with Windows, download and install the Typhoon H GUI. while you are getting ready to fly, plug the USB in, run the GUI and look at the GPS Status which includes HDOP.

gwhuntoon · Sep 18, 2016

mwelr said:
GPS should not be turning off mid flight, call Yuneec or your dealer and get it sorted.

For sat visibility my H and ST16 can normally see all of the available sats as per this site..Visibility If you are in the US I don't think you have much GONLASS coverage so you will need to toggle off that switch.

Actually I wouldn't toggle off GLONASS. Russian satellites are probably more over the US than anywhere else. My Cheerson CX 20 will only get 6-8 satellites without GLONASS. My H gets 12-20 with it.

banned user · Sep 18, 2016

gwhuntoon said:
Actually I wouldn't toggle off GLONASS. Russian satellites are probably more over the US than anywhere else. My Cheerson CX 20 will only get 6-8 satellites without GLONASS. My H gets 12-20 with it.

I'm not knowledgeable like you on GPS but I saw the map on this page and others similar to it before, looks like a big hole around most of the US? GLONASS Modernization

Rayray · Sep 18, 2016

gwhuntoon said:
Actually I wouldn't toggle off GLONASS. Russian satellites are probably more over the US than anywhere else. My Cheerson CX 20 will only get 6-8 satellites without GLONASS. My H gets 12-20 with it.

Exactly my experience here in Texas. You need all the GPS Sats.
Kylen, you mentioned trees, but you were not flying under them, were you, or going under trees with the ST-16? In Angle mode, right?

Also, before you start the props, let the bird sit there, don't move it and don't get too close. Watch the GPS Sats a minute or so until the H stops picking up new ones and says ready (on the left). The ST-16 should have, my opinion, 8 or more GPS Sats, and the H 11 or more.

Best of luck to you. Do not hesitate to call Yuneec if the problem repeats.

Rayray · Sep 18, 2016

mwelr said:
I'm not knowledgeable like you on GPS but I saw the map on this page and others similar to it before, looks like a big hole around most of the US? GLONASS Modernization

Hey mweir, how's it going? The Russians have completed the program, and their bird are flying.