Worrying about DJI Drones

[Paint Rock Drones]

I like your take on this. I would like to learn more about this unlocking process
Do you have a recommended reference where I could learn how? Thanks

Zone unlock is available through Fly Safe - DJI
There are a number of youtube videos that can walk you through it if it isn't clear.

 

[snowghost]

Your drone isn't restricted to 400 ft above it's launch point.
DJI drones can get to 1640 ft higher than their launch point.

I know that. I'm just posing the question that if it there were a strict 400' AGL you couldn't do towers.

 

[Chaosrider]

If that happened, you'd see a hacking community spring up to find vulnerabilities almost immediately. Plus, it's getting much easier to build your own...completely free of any restrictions.

I completely agree. I went to Caltech, and it's hard to describe the strength of the "beat the system" response among nerds.

In general, reasonable restrictions will get followed, and excessive restrictions will get busted.

The development of the LSA/Sport Pilot rules evolved from a widespread disregard for ultralight weight restrictions. I can say more about that if there's any interest.

TCS

 

[Chaosrider]

The aircraft only knows height relative to takeoff. It does not know altitude AGL.

I think I'm missing something, since there seems to be an easy fix to this.

The GPS signal that the drone receives contains the MSL altitude of the launch point. The drone knows how high it is above the launch point.

Wouldn't it be a simple software fix to tell the drone (or the controller) to just do the math?

Thx,

TCS

 

[Paint Rock Drones]

I think I'm missing something, since there seems to be an easy fix to this.

The GPS signal that the drone receives contains the MSL altitude of the launch point. The drone knows how high it is above the launch point.

Wouldn't it be a simple software fix to tell the drone (or the controller) to just do the math?

Thx,

TCS

It does do the math. But unless you go straight up, and assuming the ground isn't flat (e.g. you fly over a slope) then the GPS based MSL from the drone minus the launch point is not an accurate AGL reading as soon as you move away from the launch point.

 

[Chaosrider]

It does do the math. But unless you go straight up, and assuming the ground isn't flat (e.g. you fly over a slope) then the GPS based MSL from the drone minus the launch point is not an accurate AGL reading as soon as you move away from the launch point.

I'm still not seeing the problem.

The drone knows it's GPS location. The GPS signal contains the MSL of the GPS location on the ground below it. The GPS location of the launch point provides the MSL of the launch point, with the drone at 0 ft AGL just prior to launch. The drone knows how high it is above the launch point.

The math just doesn't seem that hard.

Perhaps it's a precision question. As long as I have the AGL +/- 20 feet, that's just fine for me. 1000 ft distance is as far as I can reliably see it VLOS, even with the strobe.

Are you suggesting that the GPS altitude could be more than 20 ft off, at a distance of 1000 ft?

I've seen discussion around this before, but I still don't have a clear understanding.

What would be the limiting factor in the system that would prevent getting AGL altitude +/- 20 ft?

Thx,

TCS

 

[DoomMeister]

I'm still not seeing the problem.

The drone knows it's GPS location. The GPS signal contains the MSL of the GPS location on the ground below it. The GPS location of the launch point provides the MSL of the launch point, with the drone at 0 ft AGL just prior to launch. The drone knows how high it is above the launch point.

The math just doesn't seem that hard.

Perhaps it's a precision question. As long as I have the AGL +/- 20 feet, that's just fine for me. 1000 ft distance is as far as I can reliably see it VLOS, even with the strobe.

Are you suggesting that the GPS altitude could be more than 20 ft off, at a distance of 1000 ft?

I've seen discussion around this before, but I still don't have a clear understanding.

What would be the limiting factor in the system that would prevent getting AGL altitude +/- 20 ft?

Thx,

TCS

Altitude Accuracy

gpsinformation.net

 

[sar104]

I'm still not seeing the problem.

The drone knows it's GPS location. The GPS signal contains the MSL of the GPS location on the ground below it.

No it doesn't. The GPS data include the 3-D position of the drone (lat/long location and height AMSL), but no information on the elevation of the ground below the drone. That's why this calculation isn't possible. The drone would need to have its own DEM for the ground elevation in order to compute height AGL.

 

[Chaosrider]

Altitude Accuracy

gpsinformation.net

Altitude Accuracy

gpsinformation.net

Well, that's the supposed problem, but not the explanation. As long as it's within *20 FEET*, I don't care about any errors.

It can't even do that?

TCS

 

[Chaosrider]

No it doesn't. The GPS data include the 3-D position of the drone (lat/long location and height AMSL), but no information on the elevation of the ground below the drone. That's why this calculation isn't possible. The drone would need to have its own DEM for the ground elevation in order to compute height AGL.

OK, that helps me to look at it a little differently.

I've flown Part 61 airplanes with GPS. In every case, they displayed the AGL altitude. What you're suggesting is that it has a source of information separate from the GPS, that knows the elevation of the ground at any given GPS location, and then puts the two together to give me the AGL at my present GPS location.

OK. I'll but that.

Thanks!

TCS

 

[snowghost]

OK, that helps me to look at it a little differently.

I've flown Part 61 airplanes with GPS. In every case, they displayed the AGL altitude. What you're suggesting is that it has a source of information separate from the GPS, that knows the elevation of the ground at any given GPS location, and then puts the two together to give me the AGL at my present GPS location.

OK. I'll but that.

Thanks!

TCS

I thought you only had GPS altitude and Calibrated. I'd be curious to know where the AGL data comes from.

 

[sar104]

OK, that helps me to look at it a little differently.

I've flown Part 61 airplanes with GPS. In every case, they displayed the AGL altitude. What you're suggesting is that it has a source of information separate from the GPS, that knows the elevation of the ground at any given GPS location, and then puts the two together to give me the AGL at my present GPS location.

OK. I'll but that.

Thanks!

TCS

That's correct - some GPS avionics have that option.

But also note that height AGL is much more useful in manned aviation where altitudes flown are generally much higher. Drones fly so close to the ground, relatively speaking (< 400 ft), that lack of DEM resolution and obstacle heights become much more important, and relying on computed AGL heights to avoid hitting things is going to be unreliable. While it could be useful to avoid breaking the legal height limit, pilots would try to use it for terrain and obstacle avoidance and I suspect that's one reason that DJI and others haven't implemented it - too many muppets would crash and blame the AGL readings.

 

[BanditsRoost]

I'm worried that my significant investment in DJI drones will be denied use in the U.S. with the current state of U.S. / China affairs.
I'm not certain but it seems like the U.S. is denying the official purchase of DJI drones for the federal government (maybe state governments too & local police?).
I have also been concerned with the frustrating DJI locking of their drones in U.S. airspace, just doesn't seem right even though there are safety reasons, but seems like DJI should just back off before they lost MANY customers. I love the DJI products but ... we will see how all of this plays out.

Are other pilots in U.S. worried? Love to hear your comments.

I suspect a lack of remote ID will curtail flights with your significant investments before the US denying purchase of DJI products will.

 

[norsehabanero]

Wait, are you saying that you can't fly higher than 400' above ground? I could've sworn it was 400' above the tallest building within a certain radius.

yes 107 permits 400 ft radius around a structure as well as above

 

[AusFlyer]

The realtionship between China and the US is a tit for tat. We become the victims. The US pesters Huawei and keeps their CFO in Canada 2 years under house arrest and buys no governmental DJI drones. They retaliate by imposing restrictions. A kindergarten. I live in Australia that for some reason does the same. I love my Mavic Air 2 and my Osmo after the complete collapse and lack of product development at GoPro. But we have no restrictions so far. We will probably end up with world war 3 and then nobody can fly. As to the matter of idiots with drones, spoke today with someone who usually takes Mavic Pro to 500-600 metres. Told me it was completely legal. I could not convince him he committed an offence. It felt like discussing with an anti COVID vaxxer. Alternative facts………

 

[jaja6009]

I am involved in these DJI ban threads from the FCC commissioner's recent comments on a total DJI ban. I like most DJI owners did take notice and did worry about what effects there could be to me.

Recent comments from this commissioner though have made me feel more confident. This person seems to be a bit off, and seems to just be throwing around ideas that to me make him seem uneducated at best, and off his rocker at worse.

Check out his recent comments on robotic dogs and robotics in general. I myself feel better now. His Twitter feed reads like a spoof, but unfortunately it is real.

Spot robotic dog lands on US FCC commissioner's 'banned' wish list

FCC commissioner Brendan Carr wants to ban Spot, the robotic dog developed by Boston Dynamics, because he knows how the movie "I, Robot" ends.

dronedj.com

 

[sar104]

I am involved in these DJI ban threads from the FCC commissioner's recent comments on a total DJI ban. I like most DJI owners did take notice and did worry about what effects there could be to me.

Recent comments from this commissioner though have made me feel more confident. This person seems to be a bit off, and seems to just be throwing around ideas that to me make him seem uneducated at best, and off his rocker at worse.

Check out his recent comments on robotic dogs and robotics in general. I myself feel better now. His Twitter feed reads like a spoof, but unfortunately it is real.

Spot robotic dog lands on US FCC commissioner's 'banned' wish list

FCC commissioner Brendan Carr wants to ban Spot, the robotic dog developed by Boston Dynamics, because he knows how the movie "I, Robot" ends.

dronedj.com

He just keeps digging. It's hard to imagine that anyone in public service would deliberately act like an imbecile, so maybe he really is as stupid as he appears to be.

 

[DoomMeister]

He just keeps digging. It's hard to imagine that anyone in public service would deliberately act like an imbecile, so maybe he really is as stupid as he appears to be.

All the more reason to take him off of the public payroll. His cheese never was on the cracker. What an absolute idiot!

 

[Jagerbomb52]

His cheese never was on the cracker.

LOL never heard that one before, save for when I might need it.
Thanks

 

[Robert Prior]

It's hard to imagine that anyone in public service would deliberately act like an imbecile

I dunno. As a Canadian, having the head of Homeland Security publicly blaming the 9/11 hijacking on poor Canadian border security nearly a decade after the attacks while prominent politicians defend her rather lowered my bar for what constitutes imbecility…

https://www.cbc.ca/news/world/mccain-defends-napolitano-insists-9-11-perpetrators-came-from-canada-1.830149