Mavic 2 Pro lost a signal

[NicVl87]

Hi,

Briefly situation.

I flew 367-400 meters through the city (I stood 367-400 meters from the drone) on altitude is 30 meters, there are NO high houses (max 2 floors) and no radio towers.

After that I see a message - "Weak Signal, Avoid blocking the antennas and keep the antennas parallel to and facing toward the aircraft during flight." And than - The signal disappeared for 10-15 seconds and the drone fly up for 80 meters and automatic back home.

What happened? In my opinion it is strange, even in the commercial it was said, that Mavik 2 can fly steadily in the city.


P.S I bought drone 5 days ago, flew 3-4 times.

Thanks

 

[mavic 999]

Hi,

Briefly situation.

I flew 367-400 meters through the city (I stood 367-400 meters from the drone) on altitude is 30 meters, there are NO high houses (max 2 floors) and radio towers.
After that I see a message - "Weak Signal, Avoid blocking the antennas and keep the antennas parallel to and facing toward the aircraft during flight." And than - The signal disappeared for 10-15 seconds and the drone fly up for 80 meters and automatic back home.

What happened? In my opinion it is strange, even in the commercial it was said, that Mavik 2 can fly steadily in the city.

Thanks

You flew 400 metres through the city with no buildings higher than 2 floors. ( Mod Removed )

 

[wackerpw]

Hi,

Briefly situation.

I flew 367-400 meters through the city (I stood 367-400 meters from the drone) on altitude is 30 meters, there are NO high houses (max 2 floors) and radio towers.
After that I see a message - "Weak Signal, Avoid blocking the antennas and keep the antennas parallel to and facing toward the aircraft during flight." And than - The signal disappeared for 10-15 seconds and the drone fly up for 80 meters and automatic back home.

What happened? In my opinion it is strange, even in the commercial it was said, that Mavik 2 can fly steadily in the city.

Thanks

Signal noise can and will interfere!

 

[Keule]

You flew 400 metres through the city with no buildings higher than 2 floors. ( Mod Removed )

Being rude and calling names doesn't help the OP.
He asked a question, maybe he is new to operating a drone, why don't explain the issues to him?

 

[Keule]

@NicVl87, what happed is as follows:
You flew your aircraft beyond LOS (line of sight), the communication between the remote control (RC) and the aircraft (AC) was lost, blocked by buildings, trees or whatsover.
After communication link was lost, the aircraft switched into RTH mode (Return To Home) and did what the settings in GO4 were set to (climb to a specific height, here: 80m and fly to the point where you took off from)

For the future:
- please read the manual
- understand airspace structure by using Google, Youtube or other social media or simply ask
- understand and follow your local regulation about flying a drone (when, where, how and so on)

 

[NicVl87]

оkay, thanks.

 

[Cymruflyer]

@NicVl87, what happed is as follows:
You flew your aircraft beyond LOS (line of sight), the communication between the remote control (RC) and the aircraft (AC) was lost, blocked by buildings, trees or whatsover.
After communication link was lost, the aircraft switched into RTH mode (Return To Home) and did what the settings in GO4 were set to (climb to a specific height, here: 80m and fly to the point where you took off from)

For the future:
- please read the manual
- understand airspace structure by using Google, Youtube or other social media or simply ask
- understand and follow your local regulation about flying a drone (when, where, how and so on)

The OP did not say he lost line of sight with his drone, therefore you are assuming he did, not good, best to first ask if he lost sight of it before he had that message show. I have been flying my Mavic 2 Pro where I have in the past flown my Mavic Pro (which never sent a weak signal message during flight) and close to me and high above me, as in about 320 feet, so no problem with line of sight or interference. This has happened on about three or four occasions so far, showing a weak signal message pop up.

There is no way that should be showing up for me, but it has done. I shall keep track in future of height and distance when this happens because it really concerns me that such a message shows when it is less than 600 feet away. It may just be a problem somewhere with the Mavic 2 Pro on some models. I would love to know why mine stated weak signal.

Now if the OP did lose sight of it due to it going around or behind a building, that is a different matter, that was not the case in my situation.

 

[Keule]

The OP did not say he lost line of sight with his drone, therefore you are assuming he did,

No, math did:

flying at 30m height with 400m distance gives you an angle of 4.29° from the operator location between RC and AC.
OP described its enviroment as 'there are NO high houses (max 2 floors) and no radio towers'
If you are, theoretically' putting an obstacle (houses, trees) higher than 3.75m between RC and AC at a distance of 50m from the RC operator, then we can not speak of LOS anymore.
(i'm only talking about LOS in context of wave propagation, not VLOS)

(A 2 storey building is approximately, let's say, 10m high)
OP stated he was flying in the city, so there should multiple buildings ... (OK, i assume that...)

Of course the 2 way communication between RC / AC does not stop at that obstacle, but the signal can be more or less significat disrupted. (Lookup 'LOS wave propagation' and 'Fresnel zone' on that topic)

The control link was definetly broken at some point, as the aircraft initiated failsafe RTH as described by the OP: 'The signal disappeared for 10-15 seconds and the drone fly up for 80 meters and automatic back home. '

If other factors such as incorrect antenna position, distance from RC to nearest building or other external interferences (i.e. home WiFi hotspots) played a role in that case, i can't tell, that would be speculation.

 

[Cymruflyer]

Brilliant deduction Holmes... however you are still speculating here, therefore, we need to hear from the OP to be sure. You are speculating/assuming he lost sight due to a building. What if he flew straight down a street in the city? In that scenario he would not have lost any signal strength because he was in a straight line of sight situation, therefore, your speculation would fall apart. I suggest we wait to here back from the OP to see if he was in fact flying straight down a street in that city or if he was in fact up over building that would of course, cause a possible disruption to signal. No math needed here, just an answer from the OP who had the problem.

 

[Canuk]

My guess is the OP is gone as nobody likes getting there butt chewed out .
Lately people start ranting before they know the complete story .

 

[NicVl87]

I doubt there was a direct visibility. There was a slight turn in the street.

Today, the connection has disappeared 2 times. And always around 350-500 meters. I was embarrassed only by the fact that the manufacturer stated that Maviс 2 pro should keep the signal more stable in the city, but it lost it in the small town (village) after 300m fly.

 

[DanMan32]

I've rarely gone past 1500ft or so in areas with lots of houses and trees in suburban areas.
Specs are with ideal conditions.
What's improved is dual band, and better use of bands to minimize signal loss.

 

[gnirtS]

No matter what protocol it uses it still has to follow basic physics - microwaves wont propagate through solid objects regardless of whether those are leaves, trees, buildings or anything else.

 

[FormerMember07122019_2]

There is an important point to note which may, or may not be the case here. The position of the antennas on the controller are fairly critical. Others have posted (sorry, don’t remember who) about antennae theory. I have recently re-educated myself and can assure you that the direction of the antennas are very important. As a previous poster pointed out the antennas radiate a signal as if a donut is placed on them. The primary radiation pattern is perpendicular to the orientation. To put it differently, you get maximum signal strength when the the antennas are parallel to the drone. Remember, the corresponding antenna on the Mavic 2 are in the front legs, so if the drone is far away you need to point the antennas on the controller straight at the sky to get the strongest signal. Conversely, if you point the antennas directly at the drone the signal actually approaches zero. At close range this is not as critical due to scattering effects of the atmosphere but at longer distances it can make all the differences in the world. Obstacles still have a huge impact with metal content being the worst enemy.

Hope this helps.

Ken

 

[kilomikebravo]

..you get maximum signal strength when the the antennas are parallel to the drone.

Ken: I think you meant to type "perpendicular to the drone" (when it's not overhead) and parallel when it is.)

 

[FormerMember07122019_2]

Hi KiloMikeBravo,

Thanks for fact checking me. I guess I could have been clearer. What I said is technically correct but I see the potential confusion. Since the legs of the drone are the antennas, when the drone is far away the controller antennas need to pointed up, this makes them parallel to the drones antennas. I can see if you think of the drone as a single body it would seem to be perpendicular but antenna to antenna are parallel. Interestingly, when the drone is overhead, in the picture you show from the manual, shows the controller antennas perpendicular to the drone antennas which is not ideal from a signal strength but the other choice is worse.

 

[Cymruflyer]

Hi KiloMikeBravo,

Thanks for fact checking me. I guess I could have been clearer. What I said is technically correct but I see the potential confusion. Since the legs of the drone are the antennas, when the drone is far away the controller antennas need to pointed up, this makes them parallel to the drones antennas. I can see if you think of the drone as a single body it would seem to be perpendicular but antenna to antenna are parallel. Interestingly, when the drone is overhead, in the picture you show from the manual, shows the controller antennas perpendicular to the drone antennas which is not ideal from a signal strength but the other choice is worse.

Hmmmm, now I'm confused again. Are these photos correct or not? Do the signals from the antenna go out from the side that face away from the person holding the controller or do they propagate both back and front of the flat sides? If the drone is above you, do you then need to hold the controller tilted up so the back side of the antenna are facing the drone?

 

[DanMan32]

It's a circle around the antenna sticks, not a laser from its tips.

 

[FormerMember07122019_2]

The pictures from the manual are correct. I was trying to explain technically (maybe a bit too much) what was happening.

Ken

 

[Cymruflyer]

It's a circle around the antenna sticks, not a laser from its tips.

Okay, so the signal is equally as strong all around the antenna then. I will say I have had a few times when it says signal strength low while the drone is directly above and I hold the controller level with antenna at about 45 degrees pointing upwards,,as it shows they should be positioned. When I tilt up toward the drone, the message goes away.