Arc V and Odd Observation

[Chaosrider]

I finally got around to putting my Arc V strobe onto one of my Mini-2s. Big sucker, compared to the regular Arc that I had on it before. And a lot brighter! Why, I'll bet I'll be able to see it...1.2 miles away...

;-)

Seriously, I'd be shocked if I could see it even a mile away, but I have increased my acceptable range a bit, and discovered an unexpected limitation. At a distance of about 2500 ft, the RC signal strength dropped to 4 bars. I pressed on just a little bit farther, and the signal dropped to 3 bars, and changed from white to red. At that point, I brought it home.

What might cause that signal degradation? There were zero obstacles between me and the drone. Nothing metallic anywhere nearby on the ground, just trees and rocks. I had, however, just gotten to the top of the ridge, although it's not obvious why that would make any difference.

Is this normal? I guess I just had the impression that the control range was greater than that.

Thoughts?

Thx!

TCS

 

[Deleted member 103366]

Where the trees in the line of sight between the drone and the controller's antennae?

 

[Phantomrain.org]

I finally got around to putting my Arc V strobe onto one of my Mini-2s. Big sucker, compared to the regular Arc that I had on it before. And a lot brighter! Why, I'll bet I'll be able to see it...1.2 miles away...

;-)

So there are many reasons why the bars drop , to many to list, and you have to learn how to fly with the bars dropping , maybe when you get to 2 bars , but always leave some height for you to climb to when loosing bars. Its just part of flying and getting to know your drone and setup.

Phantomrain.org
Gear to fly your Mini 2 in the Rain. Land on the Water.

 

[BSauce955]

I finally got around to putting my Arc V strobe onto one of my Mini-2s. Big sucker, compared to the regular Arc that I had on it before. And a lot brighter! Why, I'll bet I'll be able to see it...1.2 miles away...

;-)

Seriously, I'd be shocked if I could see it even a mile away, but I have increased my acceptable range a bit, and discovered an unexpected limitation. At a distance of about 2500 ft, the RC signal strength dropped to 4 bars. I pressed on just a little bit farther, and the signal dropped to 3 bars, and changed from white to red. At that point, I brought it home.

What might cause that signal degradation? There were zero obstacles between me and the drone. Nothing metallic anywhere nearby on the ground, just trees and rocks. I had, however, just gotten to the top of the ridge, although it's not obvious why that would make any difference.

Is this normal? I guess I just had the impression that the control range was greater than that.

Thoughts?

Thx!

TCS

What was your height? That can affect things. I've noticed the farther you go, the higher you seem to need to go to maintain a solid signal.

 

[Chaosrider]

Where the trees in the line of sight between the drone and the controller's antennae?

No, absolutely clear line of sight. The other side of my canyon is pretty steeply sloped. I was also careful to make sure the antennae were pointed at the drone.

I'm pretty careful about the 400 ft AGL rule. The creek bed at the bottom is about 150 feet below my house, so if I climb to not more than 250 ft directly after takeoff, I'll always be less than 400 ft AGL. As a practical matter, even in Sport Mode with a full power forward and climb, I get to the point where the slope starts to rise, before I get above 250 ft.

At the time of the event in question, I was within a couple of hundred feet above the ridgeline, well under 400 ft.

Thx,

TCS

 

[jimlips]

I finally got around to putting my Arc V strobe onto one of my Mini-2s. Big sucker, compared to the regular Arc that I had on it before. And a lot brighter! Why, I'll bet I'll be able to see it...1.2 miles away...

;-)

Seriously, I'd be shocked if I could see it even a mile away, but I have increased my acceptable range a bit, and discovered an unexpected limitation. At a distance of about 2500 ft, the RC signal strength dropped to 4 bars. I pressed on just a little bit farther, and the signal dropped to 3 bars, and changed from white to red. At that point, I brought it home.

What might cause that signal degradation? There were zero obstacles between me and the drone. Nothing metallic anywhere nearby on the ground, just trees and rocks. I had, however, just gotten to the top of the ridge, although it's not obvious why that would make any difference.

Is this normal? I guess I just had the impression that the control range was greater than that.

Thoughts?

Thx!

TCS

I can't comment on the Mini-2s, but on my Mavic-1, the farthest I've ever flown is al ittle over a mile. I was out over a large farm field, could no longer see the drone (but could see the strobe, and my buddy could still see the drone).

Even if you have no obstructions between the drone and your RC, there is a thing called "Free Space Path Loss" where your radio-frequency signal gets lower and lower, the farther away you get. There are LOTS of other things involved including the frequency, modulation type, bandwidth, antenna gain/loss, and receiver sensitivity and transmitter power. DJI uses frequency-hopping to attempted to overcome the heavy usage of the 2.4/5.8GHz radio bands (everyone shares it with their routers/phones/refrigerators, etc), but it can only help so much.

 

[Chaosrider]

So there are many reasons why the bars drop , to many to list, and you have to learn how to fly with the bars dropping , maybe when you get to 2 bars , but always leave some height for you to climb to when loosing bars. Its just part of flying and getting to know your drone and setup.

Phantomrain.org
Gear to fly your Mini 2 in the Rain. Land on the Water.

That's excellent information, good to know!

So down to 2 bars is OK? The only reason I hesitate is that it went down to 3 very quickly after it went down to 4, with very little additional movement.

Because of the topography of the canyon, and my flight plans, all I'll need to do to gain AGL altitude will be to come back a few feet the same way I went out! I'm way above my RTH the whole time.

This whole exercise is part of my plan to get to know my drone and set-up a little better. I've moved into an active experimentation phase, where I want to find the edges of the performance, but not cross them. I'd rather not trigger an emergency RTH due to signal loss...but I suppose a lot worse than that could happen.

Thanks!



TCS

 

[eEridani]

Antidotally - I placed a DR-02 strobe on my drone that actually disturbed the on board compass in a bad way. Had to recalibrate after install and after removal. So that strobe no longer gets near my drone.

I did do a visibility range test with my Lucorb tri-color strobe, and it was visible three miles out. Not as bright as car headlights a couple miles farther down the road, but I could see it flashing in the darkness. The DR-02 didn't make it as far. At 3 miles, it isn't what I'd consider an attention grabber though.

The test was near ideal: strobe on a hill top about 3 miles away, me on a bit taller hill. Air was a bit smoky from fires, results were conservative.

When flying around to test directionality features (tri-color), at 1000' the strobe was more than visible, and hard to miss with peripheral vision. It was also easy to see where the drone was headed White red and green showing most of the time - except pitch dips for acceleration when moving directly away.

 

[Deleted member 103366]

I'd rather not trigger an emergency RTH due to signal loss...but

Actually I think experimenting your way through all the RTH behaviours is a VERY GOOD idea, in a safe place, but reread the relevant sections of the manual before you experiment. And, where relevant, include RTH tests either side of distance/behaviour thresholds.
I'd also suggest trying the 3 failsafe behaviours. Switch the controller off. My expectations of "hover" were proved wrong, it hovered (as expected) until the low battery RTH kicked in then RTH's (unexpected).
"Land" could also lead to a hover if the drone rejects the landing site.
A curious Mavic 2 RTH caught me out twice in the same RTH when several behaviours were mixed together.

 

[vindibona1]

I don't usually press for distance on my Mini 2, but regularly mount the Arc V and a smaller red and smaller green on my Mini 2 and have had it out over 2500 feet. On my Mavic 2 pro, at night, I have had 4 Arc V's mounted, one top, one bottom and red/green on the arms and could maintain LOS for 10,000 feet which is where it became difficult to see and I turned it around to come home.

The strobes could possibly interfere with signal strength, but it would probably be in conjunction with obstructions. I was out flying over a frozen lagoon with trees separating my Mini 2 and the controller. I thought it would be cool so fly just over the ice, but as I got a bunch lower than the tree line I lost signal altogether and somehow managed to get it back up to fly it home. I don't think it had anything to do with the strobe.

I'm sorry that I don't keep an active log and try to stay within VLOS all the time. What I can tell you is that without strobes, during daylight I lose visuals on my Mini at about 400' but with strobes I can see where it is clearly to about 600'. At night the visual distance is exponentially greater.

 

[Chaosrider]

Antidotally - I placed a DR-02 strobe on my drone that actually disturbed the on board compass in a bad way. Had to recalibrate after install and after removal. So that strobe no longer gets near my drone.

I did do a visibility range test with my Lucorb tri-color strobe, and it was visible three miles out. Not as bright as car headlights a couple miles farther down the road, but I could see it flashing in the darkness. The DR-02 didn't make it as far. At 3 miles, it isn't what I'd consider an attention grabber though.

The test was near ideal: strobe on a hill top about 3 miles away, me on a bit taller hill. Air was a bit smoky from fires, results were conservative.

When flying around to test directionality features (tri-color), at 1000' the strobe was more than visible, and hard to miss with peripheral vision. It was also easy to see where the drone was headed White red and green showing most of the time - except pitch dips for acceleration when moving directly away.

I've been strictly a daylight flyer so far, and I'm likely to stay that way until it gets warmer!

When I do dip my toe into night flying, it will be very gradually. There are virtually no lights in this canyon, and there are trees and rocks and steep mountains everywhere.

One thought that just occurred to me is that if Litchi will let me fly waypoints with the Mini-2, I could map out a simple and super-safe course in the daylight, and then fly that course at night to see what it looks like. I don't think seeing the drone at night will ever be a problem. My concern will be with being able to see the surrounding hazards and obstructions.

But, now that I've thought about it a bit more, I'm definitely going to have to do it!

Thx!



TCS

 

[eEridani]

The stock LED's were useful out a few hundred feet. Past that I could not tell which way the drone was pointed. The tri-color Lucorb strobe on top cured the directional control issue well past 1000'. The great thing about it is it solves 99% of my night flight lighting issues in one 17g package that hooks on top the battery. Sweet and simple. The night rig is simply to be prepared. The Air 2 doesn't do well for night video, and there's really not much point to flying in pitch black.

 

[vindibona1]

I've been strictly a daylight flyer so far, and I'm likely to stay that way until it gets warmer!

When I do dip my toe into night flying, it will be very gradually. There are virtually no lights in this canyon, and there are trees and rocks and steep mountains everywhere.

One thought that just occurred to me is that if Litchi will let me fly waypoints with the Mini-2, I could map out a simple and super-safe course in the daylight, and then fly that course at night to see what it looks like. I don't think seeing the drone at night will ever be a problem. My concern will be with being able to see the surrounding hazards and obstructions.

But, now that I've thought about it a bit more, I'm definitely going to have to do it!

Thx!



TCS

IMO you should get at lest one clear strobe. ARC V would be my recommendation. During the day just mount it on the bottom, clear of the ventilation. On a bright day you can see it out to about 1600'. Without a strobe my visual contact stops at around 400'. For me, they are really handy in visually requiring my drone in the sky if I take my eyes off of it for a few seconds. I actually began with a single ARC II, the added smaller red/green strobes for the arms, which now I use front and back if possible. FWIW I tried the Lucorb and sent it back. A while back wrote up a comparison thread which you may or may not find interesting. Link below.

Lucorb vs Firehouse

 

[Chaosrider]

What was your height? That can affect things. I've noticed the farther you go, the higher you seem to need to go to maintain a solid signal.

I've open a distinct thread for the height issue. I was a little over 1100 feet above launch point, but below 400 ft AGL.

Thx,

TCS

 

[Chaosrider]

I can't comment on the Mini-2s, but on my Mavic-1, the farthest I've ever flown is al ittle over a mile. I was out over a large farm field, could no longer see the drone (but could see the strobe, and my buddy could still see the drone).

Even if you have no obstructions between the drone and your RC, there is a thing called "Free Space Path Loss" where your radio-frequency signal gets lower and lower, the farther away you get. There are LOTS of other things involved including the frequency, modulation type, bandwidth, antenna gain/loss, and receiver sensitivity and transmitter power. DJI uses frequency-hopping to attempted to overcome the heavy usage of the 2.4/5.8GHz radio bands (everyone shares it with their routers/phones/refrigerators, etc), but it can only help so much.

I have more quantitative data about this now. I have three Mini-2s, Enterprise, Defiant, and Phoenix. I have 2 launch sites at my house, the forward flight deck, and the rear flight deck.

The first in this series of tests, when I saw the signal degradation start at 2500 ft distance was from the rear flight deck.

The next day, I did the same test with Defiant from the forward flight deck. Different drone, different controller. At 3000 ft out, the signal was strong, mostly still 5, with occasional burps down to 4.

Then later that afternoon, I did the test with Phoenix from the rear flight deck. 2500 ft out, and the degradation starts.

This suggests the takeoff location makes a difference. I'll know more after another test later today.

The difference is that the forward flight deck is wide open, at least in the direction of the canyon floor, there are few trees right near the launch point. The rear flight deck, however, is nestled among the trees, and carved into the cliffside.

My current theory is that even though there were no obstructions at all in my LOS to the drone, the surrounding trees and house and other ground clutter degrades the strength of the control signal from the rear flight deck.

Thoughts?

Thx!

TCS

 

[Chaosrider]

Actually I think experimenting your way through all the RTH behaviours is a VERY GOOD idea, in a safe place, but reread the relevant sections of the manual before you experiment. And, where relevant, include RTH tests either side of distance/behaviour thresholds.
I'd also suggest trying the 3 failsafe behaviours. Switch the controller off. My expectations of "hover" were proved wrong, it hovered (as expected) until the low battery RTH kicked in then RTH's (unexpected).
"Land" could also lead to a hover if the drone rejects the landing site.
A curious Mavic 2 RTH caught me out twice in the same RTH when several behaviours were mixed together.

OK, this is interesting. I was thinking about doing that kind of "advanced" RTH testing, which I may do after reviewing the manual on the issue.

My concern is that if, for whatever reason, the test fails, and the RTH doesn't work properly, the drone will be effectively unrecoverable. So the question then becomes, am I interested enough in doing the test to risk the $225 flyaway replacement cost?

The answer is...not yet!

But that raises another question. Suppose, hypothetically, someone was willing to insure me for the $225 flyaway cost to do the test? If the test works, and the drone comes home, they pay me nothing. If the test fails and the drone is lost, they would pay me the $225 replacement cost.

Would that be legal? I have my 107. Suppose I was willing to pay $25 for that coverage, which I probably would be if anyone was willing to offer it. Would that be legal?

Inquiring minds want to know!



TCS

 

[BSauce955]

...But that raises another question. Suppose, hypothetically, someone was willing to insure me for the $225 flyaway cost to do the test? If the test works, and the drone comes home, they pay me nothing. If the test fails and the drone is lost, they would pay me the $225 replacement cost.

Would that be legal? I have my 107. Suppose I was willing to pay $25 for that coverage, which I probably would be if anyone was willing to offer i. tWould that be legal?...

I fail to see how it wouldn't be legal. Maybe without your Part 107 but even that is unlikely as you're just getting paid for your drone not for flying it.

 

[Deleted member 103366]

whatever reason, the test fails, and the RTH doesn't work properly,

so far, in hindsight, all my RTH's have been in accordance with correct behaviour.
The ones where something apparently went wrong turned out to be due to me having the wrong expectations. Once the manual was reread with the observed behaviour in mind I could see that the drones had behaved correctly.

 

[eEridani]

I've flown far and wide, and then messed up and flew my drone behind something I didn't expect to get behind. It ended in an LOS; drone disconnected from the controller.

The drone initiated Smart RTH - first backed up 50 feet (more a maybe it did than demonstrable in the log); then the drone rotated and pointed to my home point (note there was a hill between the drone and me); then the drone continued its Smart RTH (distance was such the drone angled downhill to save battery and further buried itself behind the hill); APAS notice the ascending ground and decided altitude was needed and continued to ascend until clear of the hill (once clear signal was restored so I retook control).

The lesson was to pay a bit closer attention to the drone when navigating around obstacles. I expected a horizontal loss of visual as I swung around the pillar, but had I noticed the drone dipping behind the hill top vertically I would have recovered without incident.

All this other hypothetical aside, I am reasonably confident DJI has tested RTH in many environments and found it to be useful most of the time. The fact it worked so well in my one actual OMG event highlights its capability to do the right thing.

The flip side is all of the underlying settings needed to be aligned with the starts for the RTH to have worked. It is far too easy to change an RTH setting and get a less than desirable outcome. One tap on the wrong area of screen will ruin your day in you don't notice the tap (APAS mode change Bypass->Brake->Off).

 

[Chaosrider]

I don't usually press for distance on my Mini 2, but regularly mount the Arc V and a smaller red and smaller green on my Mini 2 and have had it out over 2500 feet. On my Mavic 2 pro, at night, I have had 4 Arc V's mounted, one top, one bottom and red/green on the arms and could maintain LOS for 10,000 feet which is where it became difficult to see and I turned it around to come home.

The strobes could possibly interfere with signal strength, but it would probably be in conjunction with obstructions. I was out flying over a frozen lagoon with trees separating my Mini 2 and the controller. I thought it would be cool so fly just over the ice, but as I got a bunch lower than the tree line I lost signal altogether and somehow managed to get it back up to fly it home. I don't think it had anything to do with the strobe.

I'm sorry that I don't keep an active log and try to stay within VLOS all the time. What I can tell you is that without strobes, during daylight I lose visuals on my Mini at about 400' but with strobes I can see where it is clearly to about 600'. At night the visual distance is exponentially greater.

Interesting. I wonder if the snow covering parts of the mountains could contribute to the problem?

After running the test yesterday, it's clear that the bulk of the range difference that I've noticed is the result of the launch site, and not differences in the drones. From the forward flight deck, I get about 3000 ft of useful control range. From the rear flight deck, only about 2500.

It's definitely not an issue with any single drone. I have 3 Mini-2s, and they all exhibit the same behavior.

For any of you who have flown a Mini-2 beyond 3000 ft range, how many bars of control signal strength did you have? For anyone who has flown a Mini-2 a mile away, what signal strength did you have at that range? It's starting to look to me like the purported 6 mi range isn't dimly close to right.

Thoughts? Observations?

Thx!

TCS