Signal loss - flight review

[flabombarda]

Guys,

Coul you please help me reviewing the flight Airdata UAV - Flight Data Analysis for Drones

Go to the sensor tab and you will see the purple area, at some point I lost signal for about 20 seconds, the app (lichi) was showing full bars of signal for both controller and video transmission and suddenly I was disconnected (both, controller and app) RTH started, and after something like 20seconds I was able to get back the control, cancel RTH and return.

I was in the middle of the country side, not close to any antenna or any transmission system. That happened at 2.2Km distance from the controller, clear line of sight.

Is there any setting on the controller or aircraft level I could play with trying to prevent this ? This was not the first time it happened, sometimes even closer I start to lose video signal.

Any clue ?

Thanks

 

[Gary cato]

it can happen anywhere, interference comes from many sources, sometimes u can fly through it and regain signal if it is just a second or two of interference. It can happen at 50 meters or 3000 meters, in the countryside or in town.

You gotta keep a close eye on it and realise that this is not a problem with the Mavic but with the signal somewhere down the flight line.

i had the same at 2300 metres out around 1,4 miles in clear countryside, yet i have flown in more suburban and congested areas and not had any issues up to 1000 metres.

there is a switchable video feed but the Mavic does sear ch for the best feed and sometimes there is not one. The HD feed drops to 720 anyway as you get further out.

watch for the RC symbol flashing before those bars drop, if that happens then you are entering into some kind of interference zone and that means signal can drop out very rapidly.

 

[flabombarda]

Thanks for the advice Gary.
I´m aware this is not a mavic problem I was just wondering if there is any tuning I could do on the communication level to reduce this.

I also noticed is that the RTH speed is very low, like 17Km/h is that normal?

 

[AlanTheBeast]

This is sort of your POV from Google Earth.
That loop E .. F is not ideal LOS. So your issue could be related to Fresnel Zone Clearance.

 

[AlanTheBeast]

Thanks for the advice Gary.
I´m aware this is not a mavic problem I was just wondering if there is any tuning I could do on the communication level to reduce this.

I also noticed is that the RTH speed is very low, like 17Km/h is that normal?

See my other post wrt signal.

I show you doing 31 mph (50 km/hr) ground speed on that leg with a pretty stiff tail wind.

 

[Gary cato]

Thanks for the advice Gary.
I´m aware this is not a mavic problem I was just wondering if there is any tuning I could do on the communication level to reduce this.

I also noticed is that the RTH speed is very low, like 17Km/h is that normal?

Alan is the master here i have to bow down to his knowledge i am afraid. All i can add is that speed is denoted by wind and if u had a tail wind and was doing 50kmh you were either in sport mode or maybe had OA off as i think even with a tail wind you would struggle to get 31MPH in normal mode.

Yesterday i did a quick battery run down flight and in normal mode i was making 3mph lol yea the winds were **** high. i had to switch to sports mode as i watched the Mavic almost at standstill 100 meters away with 6 seagulls heading in for the attack. (really they decided the Mavic was pissing them off, started with one gull and within 5 minutes there was 6).

first time ever i have had that problem with a Mavic. (only other time was freeclimbing a cliff with no ropes in Jersey. 120 feet up i got too close to a nest.) On that occasion even a special forces abseiler could not have descended that 120 as quick as i did. Really they tried to take me off tat cliff. it is only when they are one foot above your head you realise how big they are.

back to the OP. the winds at ground level can be zero but the gusts at 50 meters may be 20 to 30. The Mavic is a powerful drone but she is no inspire where winds are concerned.

As said Alan is the man here for the more diagnostic and advanced advice. All i can do is the basics after that i leave it to these guys.

 

[AlanTheBeast]

As said Alan is the man here for the more diagnostic and advanced advice. All i can do is the basics after that i leave it to these guys.

Not quite master. Prodigy in training with various others guiding me who are pretty sharp. (I do have a lot of experience with airborne systems, radio, radar, GPS though - so there's that...) BudWalker, msinger, Robbyg, Cyberpower 678 ... all have insight, experience, tools and analytical skills that are quite amazing...

 

[Gary cato]

Not quite master. Prodigy in training with various others guiding me who are pretty sharp. (I do have a lot of experience with airborne systems, radio, radar, GPS though - so there's that...) BudWalker, msinger, Robbyg, Cyberpower 678 ... all have insight, experience, tools and analytical skills that are quite amazing...

You are not far off the rest Alan, i am not kissing anyone's *** here but you gotta give credit where its due.

When you write i read

 

[flabombarda]

Thank you all for the inputs here. You are right about the wind, today was VERY windy here, about 20mph.
Regarding the speed, I wasn´t in sport mode, just with obstacle avoidance off the whole time

 

[Gary cato]

Thank you all for the inputs here. You are right about the wind, today was VERY windy here, about 20mph.
Regarding the speed, I wasn´t in sport mode, just with obstacle avoidance off the whole time

yea i guessed as much from Alan's speed reading lol, OA will slow you right down, its a good middle stage in winds to first turn off OA to give you some extra help and if that does not work sport mode is the way to go.

 

[AlanTheBeast]

Thank you all for the inputs here. You are right about the wind, today was VERY windy here, about 20mph.
Regarding the speed, I wasn´t in sport mode, just with obstacle avoidance off the whole time

50 km/hr is like P-mode with OA off and the pitch stick pinned forward - about what I'd expect from the MP in RTH with OA off - though with that tailwind I'd have expected a higher ground speed.

Wind was 20 .. 25 mph on that leg.

(As a side note, for HD to even compute wind it has to see data that indicates max speed for the given mode (since there is no TAS sensor)).

 

[AlanTheBeast]

You are not far off the rest Alan, i am not kissing anyone's *** here but you gotta give credit where its due.

When you write i read

Some people barf, others throw stones...!

 

[flabombarda]

Alan, what did you see to calculate the wind on that particular leg ?

 

[AlanTheBeast]

Alan, what did you see to calculate the wind on that particular leg ?

Logged into my HealthyDrones account, linked to your log above and looked at the winds. You have to have a HD account to do that.

 

[flabombarda]

Thanks Alan, I was curious about the process to determine the wind.

 

[Gary cato]

Thanks Alan, I was curious about the process to determine the wind.

Your signal loss happened at your lowest altitude (which was still quite high) but it starts to deteriorate as you fly directly to the side of that building, it is their that you then lose signal. That looks like some quite dense greenery their as well. Looks like that building has some kind of lorry operation going on down there.

Maybe nothing to do with it at all to be honest, just interesting that you start to lose signal just as you run alongside that building.