What are you getting for range in an urban environment?

[kds]

DJI's specs list the Mavic Mini as having 4,000m (13,123ft, or just under 2.5 miles) as the RC-aircraft range under ideal, unobstructed conditions.

This test by Billy Kyle got a range of about 9,000ft over a river in Philadelphia. This test over a river in a non-urban environment seems to confirm DJI's 4,000m rating.

I've been launching from home in a suburban development and the furthest I've been able to go is 2,500 ft before I start getting interference or complete loss of RC connection and RTH is activated. I knew I would get less than the rated range, but I haven't been able to even get half as far.

What has everyone else been getting in an urban environment?

 

[DanMan32]

Funny you should post this. I got same results: 2500-3000ft at 200-300ft altitude. Much worse if it was behind me where there were trees between us LOS.

 

[chriscuk]

I'm waiting on a thread to be approved by moderators but I've got a pile of maths in there explaining range. Long story short, I can't see how DJI get the claimed 4000m safely with the FCC model

 

[kds]

I'm waiting on a thread to be approved by moderators but I've got a pile of maths in there explaining range. Long story short, I can't see how DJI get the claimed 4000m safely with the FCC model

I will be looking forward to reading that!

 

[F22arecool]

I got a 3700 foot range but I did not push any further because of the battery warning. If the signal got choppy I went higher to around 350 feet and the signal was clear with no lag spikes at the furthest distance.

 

[grahamjohnson10]

I managed 2962 feet today, I think I could of gone further.

 

[MAvic_South_Oz]

I saw a YT vid from an Aussie pilot and he flew his mini just under 1km (3240'), but only 40m (130') altitude, before his vid trans went a bit funny, then messages such as 'Strong signal interference', then 'Weak signal adjust antenna', finally 'RC signal lost' appeared and it went into auto RTH.

This took 75 seconds from time of first message to RTH kicking in, quite a bit longer than the stated 11 seconds in the manual for this to happen.
(Not sure if he was running IOS and no other options yet for failsafe.)
It picked up again almost immediately it turned around for home, but he let it return by itself.

He flew over businesses and homes, no doubt a lot of wifi.
Disappointingly, he also flew over main roads and large carparks with lots of traffic, as well as directly over people.

 

[WithTheBirds]

I'm waiting on a thread to be approved by moderators but I've got a pile of maths in there explaining range. Long story short, I can't see how DJI get the claimed 4000m safely with the FCC model

What maths do we need?

With respect to the claim of 4000m safely not sure what your getting at- max transmission distance in unobstructed clean RF environment suggests in most cases you should expect less.

 

[old man mavic]

it would seem from a lot of the videos that altitude plays a big part in signal stability at extended range probably because at lower heights the signal is absorbed by trees and buildings and interference while it is very nice to have this info on how far can it fly, i have to agree with Mavic south oz that it is not really the thing to do flying beyond VLOS in such places

 

[MAvic_South_Oz]

it is not really the thing to do flying beyond VLOS in such places

Indeed, even with a Strobon or FHT Dual strobe and you could see the mini at a km in daylight easily, urban flying is probably more risky with these wifi drones and connection in good remote areas . . . adding in all the wifi and other such interference in urban areas only makes it worse.

I think most will fly their minis fairly close in both types of areas, I know (if I ever feel the need to get a mini) my use for it would be for travel, and the riskier flying under trees, obstacles, inside abandoned buildings etc where it would be a neat drone to use, outside in open areas I'd be probably less than a km with good LOS and strobe, but then I'd rather grab the Spark or M1P for those flights.

 

[chriscuk]

What maths do we need?

With respect to the claim of 4000m safely not sure what your getting at- max transmission distance in unobstructed clean RF environment suggests in most cases you should expect less.

What maths? The maths that explains the differences between radio transmissions at 2.4ghz vs 5ghz in regards to range and why their calculations seem "off". As for "safely" I was hoping my post would make it clear but it's not been approved by a mod yet.

Basically to make the maths work on the provided power, frequency, atmospheric losses along with receiver sensitivity the link margin has to be really low to get the numbers they are claiming.

I prefer to understand why something is doing what it is. I've had contacts around the globe on less power than this drone emits it's just understanding the hows and whys that I enjoy.

 

[Bjord]

Flying in a suburban area with the FCC version at around 250ft, I was only able to make it about 500m before I got interference warnings and then lost signal. Probably a lot of wifi from the houses.

 

[WithTheBirds]

What maths? The maths that explains the differences between radio transmissions at 2.4ghz vs 5ghz in regards to range and why their calculations seem "off". As for "safely" I was hoping my post would make it clear but it's not been approved by a mod yet.

Basically to make the maths work on the provided power, frequency, atmospheric losses along with receiver sensitivity the link margin has to be really low to get the numbers they are claiming.

I prefer to understand why something is doing what it is. I've had contacts around the globe on less power than this drone emits it's just understanding the hows and whys that I enjoy.

The 5.8 atmospheric losses might be expected to be around 7db higher than at 2.4 in ideal situations.

I think many are interested in how DJI derives the published max range figures. I know I have been and can see where you are coming from. You probably won’t get there with calculations. It is probably as simple as them doing real world testing.

 

[MAvic_South_Oz]

I think many are interested in how DJI derives the published max range figures. I know I have been and can see where you are coming from. You probably won’t get there with calculations. It is probably as simple as them doing real world testing.

That would be good to know !
Like car manufacturers, they would probably have a "test track" out back of the factory, but also may do this out in the field, open terrain, even flying from a peak to maximise LOS.

Like car manufacturers, they probably test in ideal conditions to maximise results in their favour, and like car manufactures, their "fuel use" figures are not usually achievable in the real world.

Good to know your bird as good as possible is all regards, so all these tests, and such info taken on board can assist giving people a vague picture of where to start this process.

 

[deleted member 877]

DJI's specs list the Mavic Mini as having 4,000m (13,123ft, or just under 2.5 miles) as the RC-aircraft range under ideal, unobstructed conditions.

This test by Billy Kyle got a range of about 9,000ft over a river in Philadelphia. This test over a river in a non-urban environment seems to confirm DJI's 4,000m rating.

I've been launching from home in a suburban development and the furthest I've been able to go is 2,500 ft before I start getting interference or complete loss of RC connection and RTH is activated. I knew I would get less than the rated range, but I haven't been able to even get half as far.

What has everyone else been getting in an urban environment?

On Billy Kyle's video (in the comments section), someone had a go at him about going BVLOS and he responded that it was OK because he was in radio contact with a visual observer.

What are the current FAA regulations pertaining to VLOS? Is it now OK to communicate with a VO via radio or phone?

 

[DanMan32]

He also seemed to be over traffic, though that can be deceiving. He did go over bridges with high traffic though.

 

[Deleted member 109934]

That would be good to know !
Like car manufacturers, they would probably have a "test track" out back of the factory, but also may do this out in the field, open terrain, even flying from a peak to maximise LOS.

Like car manufacturers, they probably test in ideal conditions to maximise results in their favour, and like car manufactures, their "fuel use" figures are not usually achievable in the real world.

Good to know your bird as good as possible is all regards, so all these tests, and such info taken on board can assist giving people a vague picture of where to start this process.

Don't they use FFC report test results and extrapolate that with software? I'm new to drones so I'm not sure how drone manufacturers are doing it, but I would assume the same as all wi-fi hardware manufactures, this way they can claim mind-blowing speeds, that we will never see in the real environment. They use special testing chambers to isolate the environment and then produce controlled noise etc... Testing any wireless hardware in the real-world would be pretty much impossible, it must be all in the lab to be "valid" Again not a drone expert so might be wrong.

Here is FCC report for my CAD transmitter, with those numbers you can "pretty much" predict the range in "ideal conditions"

FCC ID SS3-MR1SS51905

fcc.report

 

[MAvic_South_Oz]

Don't they use FFC report test results and extrapolate that with software? I'm new to drones so I'm not sure how drone manufacturers are doing it, but I would assume the same as all wi-fi hardware manufactures, this way they can claim mind-blowing speeds, that we will never see in the real environment. They use special testing chambers to isolate the environment and then produce controlled noise etc... Testing any wireless hardware in the real-world would be pretty much impossible, it must be all in the lab to be "valid" Again not a drone expert so might be wrong.

Here is FCC report for my CAD transmitter, with those numbers you can "pretty much" predict the range in "ideal conditions"

FCC ID SS3-MR1SS51905

fcc.report

That could well be !
Would have thought they'd have to do some sort of field testing, but maybe not.

Of course there are SO many factors that affect this, like driving a car, you have hills, head winds, etc that affect fuel use, so too drones have all sorts of potential interference, even atmospheric conditions can affect wireless signals I believe.

Battery life is also something totally fluid, at the whim of wind, flight characteristics (alt gains and how the drone is flown in aggressiveness), and such.

 

[WithTheBirds]

Don't they use FFC report test results and extrapolate that with software? I'm new to drones so I'm not sure how drone manufacturers are doing it, but I would assume the same as all wi-fi hardware manufactures, this way they can claim mind-blowing speeds, that we will never see in the real environment. They use special testing chambers to isolate the environment and then produce controlled noise etc... Testing any wireless hardware in the real-world would be pretty much impossible, it must be all in the lab to be "valid" Again not a drone expert so might be wrong.

Here is FCC report for my CAD transmitter, with those numbers you can "pretty much" predict the range in "ideal conditions"

FCC ID SS3-MR1SS51905

fcc.report

You need only look at the many range threads to see people are achieving advertised flight distances (or greater) for the various DJI drones. Whatever the means employed to determine the maximum distance figures they agree with reality.

 

[Deleted member 109934]

Outside testing to be consistent and meaningful would have to be done in the desert somewhere, air temperature, pressure, humidity, bedrock, altitude, etc. would all affect the outcome. If you start reading it, it shows you how much radiation is absorbed by holding remote in the left hand, right hand, from the top etc. all that could affect the final outcome, to have meaningful results it would have to be tested by the same person. Skinny people and fat people absorb\reflect\influence radiation differently. It is quite complex to have somehow repeatable precise results.

Hence they do this in the locked chamber and robot arm measures all of that, FCC labs look pretty much the same all over the world, and if there are any differences they are controlled. They are even specific about where and to what power outlets is testing equipment connected as it could easily influence the results.
If they are using industry standards they are using FCC reports and lab to measure it then extrapolate it.

Based on those tests they can easily calculate real-life range quite precisely, having said that we might not get that rage when testing in the city with tons of interference. So if the say 4000m it is 4000m I'm sure the take bottom numbers to avoid any lawsuits, but 99% of us living in the city will never see those numbers.