satellites
- Thread starter NRRTRAINS
- Start date
10 is not that much, 15 good and 20 perfect. Bellow 10, the Spark is at risk to switch to ATTI/OPTI mode. It means also a poor location to fly where the GPS status can change quickly.
The number not always tell you the quality of the signal received. It can be that 10 gives a better quality position where a 12 could be worst. It depends where are located the satellites in the sky (what elevation to the horizon) at that moment and what obstacles are on the signal path.
You can see more information with the app "UAV Forecast". It can predict at your location what number of satellites you can expect.
The number not always tell you the quality of the signal received. It can be that 10 gives a better quality position where a 12 could be worst. It depends where are located the satellites in the sky (what elevation to the horizon) at that moment and what obstacles are on the signal path.
You can see more information with the app "UAV Forecast". It can predict at your location what number of satellites you can expect.
I have issues with UAV Forecast and it's GPS reporting. I use it on my LG Stylo 3 phone and it will give me a report of "Not Good to Fly" based on the low number of satellites shown while sitting indoors. If I take my phone outside and wait a minute or so, the number of satellites does not change nor does the warning. My Go 4 app on my iPad Mini 4 does not see any sats. while indoors. Therefore I have to question the "Forecast" of the app in it's accuracy. I know that it could be my phone's fault but I also think that there should not be such a big difference either.
I think that the forecast is not based on the phone GPS as you can get forecast for any place.
It should be based on something similar to this: Visibility
Then you can set a mask on the horizon where you expect no satellite visible and finally UAV forecast reduce that number as per the Kp value of solar activity.
desert spark
Well-Known Member
Clouds sure mess with my satellite TV siginal
Exactly! I keep hearing people say that clouds don't interfere with GPS signals, but from my personal experience that is false. A few weeks ago, I went outside on a nice, but very overcast day to fly (same spot in my back yard where I fly frequently) and I couldn't get GPS to lock and Spark stayed in ATTI mode. The next day, same spot, but no clouds at all, I locked in 18 good GPS satellites.
I would have thought clouds affect GPS but apparently it’s affects are minimal!
Does RAIN, SNOW, or CLOUDS affect reception of GPS signals?
Does RAIN, SNOW, or CLOUDS affect reception of GPS signals?
GPS is in average good quality but there could be some period of time where the number of usable satellites at a particular location is low.
This site gives status and prediction for satellites reception based on their location in the sky: Visibility
desert spark
Well-Known Member
That’s a useful link! I guess the best thing to follow (assuming it’s accurate) is the satellite stats provided in Go 4. I have also been using UAV Forcast but the Visibility link would be good to check the accuracy of both the other apps!
That John Deere site is interesting. It said I should have 7 satellites. At 3.7 feet altitude I had 6 or 7. It would fluctuate. At 8.5 feet I had 8. At 22 feet I had 9. At 211 feet I had 11. At 213 feet I had 12, then 13, then 14, then 17. It stayed between 15 and 17 the whole time I was up there. Maybe the trees have a big influence at lower altitudes? That is a rhetorical question. I KNOW they block GPS reception. I had sufficient signal to set the Home Point at ground level and 93.2% of my flying is comfortably above the trees where I typically had 15 satellites or more. UAV Forecast said I shouldn't be flying and they are forecasting the same (No Flying) all day (24 hours) tomorrow.
Don't forget to enable also Glonass as the Spark use them.
In UAV forecast, you can set aminimum angle over horizon where the satellites are considered as visible. On a flat area it can be very low. In a mountain area it should be higher. It cut a surface in the sky where there is the highest density of satellites so obstacle like mountain can highly reduce satellites number.
I have a similar question; I got 9 satellites on a recent mission when the software said the minimum is 5 satellites. When my orthomosaic came back from 'Maps Made Easy' the map was 65 feet away from the location shown on Google earth. I used photo identifiable points found on both google maps and my orthomosaic to relocate the map successfully. But that gives me concern that if my mission is set with Google map coordinates the drone may not fly to the planned position. Is this typical for a spark? Do other Mavic product have a similar issue?
