What happens if you fly from a cliff?

[MichaelR]

This is the only way a drone could maintain a 400' AGL constant and be enforceable as a restriction. Currently it's not a constant definable attribute during flight.

Yes absolutely, I have been thinking this too. I would also like a real time barometer reading for my own interest too.

 

[Meta4]

I would like a 'real-time' barometer feature like in real aircraft. The reading from Start point is great....but i would also like an accurate AGL reading whilst in flight too. Would this extra feature be too costly or complex for a circa £1,200 copter?

Multicopters are all compromise - you can't have everything.
There are lots of things that would be nice but you can easily live without.
For AGL altitude, you would need some kind of laser or radar altimeter - think weight + cost.

These don't look particularly lightweight or cheap.
https://buy.garmin.com/en-US/US/in-.../cInTheAir-cAvionics-cRadarAltimeters-p1.html
Miniature Radar Altimeter

 

[Rumbaar]

Yes absolutely, I have been thinking this too. I would also like a real time barometer reading for my own interest too.

I'd love a built in Anemometer. The wind speed can be considerably different at 100m+, and having real-time information could be very helpful.

 

[MichaelR]

Multicopters are all compromise - you can't have everything.
There are lots of things that would be nice but you can easily live without.
For AGL altitude, you would need some kind of laser or radar altimeter - think weight + cost.

Ah ok i understand. Its a costly (and possibly heavy) feature? I have absolutely no idea what a barometer looks like, or what kind of cost they are. But with technology moving so fast, maybe it will be an inexpensive possibility before too long do u think?

 

[Meta4]

I'd love a built in Anemometer. The wind speed can be considerably different at 100m+, and having real-time information could be very helpful.

Then put your Phantom into atti mode and watch your instruments while it hovers.

Ah ok i understand. Its a costly (and possibly heavy) feature? I have absolutely no idea what a barometer looks like, or what kind of cost they are. But with technology moving so fast, maybe it will be an inexpensive possibility before too long do u think?

You have a barometer - it measures air pressure and can't tell you anything about AGL height.
I added some details of radar altimeters to my post above that might be informative.

 

[MichaelR]

As Rumbaar says, with all this new registration, legislation, and pilot accountability coming in, how can we as pilots make sure we keep within the 122m /400 ft altitude limit if we dont have real-time altitude readings.
I often fly from a high point halfway up a hill, or on the moorland, and when i fly back down the hill, the 100m altitude i have at Home Point becomes a lot higher even just 500meters away. I can tell i am a lot higher than the 100m just by looking at my ipad display. I'm well above the 122m height limit, but i have no actual idea of my true AGL.
If we are going to be open to prosecution in the future for breaking CAA rules, how can we stick within the laws?
A bit like driving a car without a speedometer and just kinda guessing that you are within the speed limit aint it..?

 

[Wolfiesden]

There are only three ways the drone could know its AGL reading. 1. using Internet and accurate topo maps. 2. Radar. 3. LIDAR. First option would require internet access during flight. Not gonna happen for a lot of folks. Second option ONLY way that could happen is if they started putting ground radar on the copters. The sonar can't possibly reach 400'. Baro is air pressure and has squat to do with AGL. The same baro reading would be valid if you were sitting on a 400' tall hill or 400' up in the air from 0 AMSL. The Baro calculations are a relative, meaning relative from set point, ie the home point I would guess. Ground radar is heavy, expensive and complicated. Not happening on a $1k copter. Last is LIDAR. Possible. However, inaccurate on reflective surfaces (water for example). And I am not sure how heavy that would be and how accurate it could be in a small package.

Would I like it? Sure. I would also like horizontal LIDIR for terrain and obstetrical avoidance during RTH. If it sees something in front of it, fly over it. Sure would be nice. Again, weight vs flight time issue. More stuff, bigger batteries, bigger motors. Its a vicious circle.

 

[MichaelR]

Then put your Phantom into atti mode and watch your instruments while it hovers.

You have a barometer - it measures air pressure and can't tell you anything about AGL height.
I added some details of radar altimeters to my post above that might be informative.

Interesting, thanks for sharing these links [emoji106] i understand a little more about the weight/cost problem with this kind of feature now.

 

[MichaelR]

There are only three ways the drone could know its AGL reading. 1. using Internet and accurate topo maps. 2. Radar. 3. LIDAR. First option would require internet access during flight. Not gonna happen for a lot of folks. Second option ONLY way that could happen is if they started putting ground radar on the copters. The sonar can't possibly reach 400'. Baro is air pressure and has squat to do with AGL. The same baro reading would be valid if you were sitting on a 400' tall hill or 400' up in the air from 0 AMSL. The Baro calculations are a relative, meaning relative from set point, ie the home point I would guess. Ground radar is heavy, expensive and complicated. Not happening on a $1k copter. Last is LIDAR. Possible. However, inaccurate on reflective surfaces (water for example). And I am not sure how heavy that would be and how accurate it could be in a small package.

Would I like it? Sure. I would also like horizontal LIDIR for terrain and obstetrical avoidance during RTH. If it sees something in front of it, fly over it. Sure would be nice. Again, weight vs flight time issue. More stuff, bigger batteries, bigger motors. Its a vicious circle.

Interesting, thanks for explaining all that.

 

[Meta4]

Laser systems may be smaller and cheaper than radar but they still cost quite a bit more than the average Phantom buyer wants to spend.
http://www.lightware.co.za/shop/en/
https://www.unmannedsystemssource.com/shop/agl-n-laser-altimeter/

with all this new registration, legislation, and pilot accountability coming in, how can we as pilots make sure we keep within the 122m /400 ft altitude limit if we dont have real-time altitude readings

If we are going to be open to prosecution in the future for breaking CAA rules, how can we stick within the laws?
A bit like driving a car without a speedometer and just kinda guessing that you are within the speed limit aint it..?

Airplane pilots managed quite well for 100 years with only barometric altimeters.
With a little experience, it's not that hard to estimate reasonably well what your height is above terrain and there's no-one out there with a tape measure checking on you.

 

[MichaelR]

Haha yeah sure. Thanks

 

[Rumbaar]

Then put your Phantom into atti mode and watch your instruments while it hovers.

How will this give me real-time wind speeds?

 

[Rumbaar]

Airplane pilots managed quite well for 100 years with only barometric altimeters.
With a little experience, it's not that hard to estimate reasonably well what your height is above terrain and there's no-one out there with a tape measure checking on you.

They were also present in the aircraft to gauge distance relative to the craft and themselves, which is not comparable to working out a distance from yourself to the drone and the drone relative to itself and the ground beneath,

 

[movius]

Nice job Robby. Just one question, how on earth do they manage to keep kids off that boat. It must be magnet

Sent from my SM-N9005 using Tapatalk

 

[Helijoc]

Ok, here is a question that I think is perfectly valid, but it maybe dumb to some.....
On a previous thread some time ago I was suggesting features/improvements that could possibly be incorporated into the next (or future) models i.e. Phantom 4 etc.
I would like a 'real-time' barometer feature like in real aircraft. The reading from Start point is great....but i would also like an accurate AGL reading whilst in flight too. Would this extra feature be too costly or complex for a circa £1,200 copter?

In atti mode it uses a barometer to maintain altitude. When you are in GPS your altitude is your AGL. GPS Does positioning and altitude.

 

[Rumbaar]

In atti mode it uses a barometer to maintain altitude. When you are in GPS your altitude is your AGL. GPS Does positioning and altitude.

But still relative to starting point of zero.

 

[impilot51]

I thought I had read that even in GPS mode, the barometer is used as part of he calculation since GPS altitude is not as accurate as Lat/Lon position.


Sent from my iPhone using PhantomPilots mobile app

 

[Meta4]

How will this give me real-time wind speeds?

The wind aloft will be similar to what you sense down on the ground but it may be stronger.
If there is no wind aloft, your Phantom in atti mode, will just hang there.
If there is a slight wind, it will be blown slowly along, showing you the speed and direction of the wind.
If it scoots along at 10 metres/sec you know you have a significant wind to deal with.
You can also get a sense of the wind in GPS mode by watching your speed as you fly into the wind.
If you can only manage 10 m/s, you know you have 5m/s against you etc.

You can see from this graph the kind of difference you can expect with increasing altitude altitude

 

[John Locke]

If we are going to be open to prosecution in the future for breaking CAA rules, how can we stick within the laws?
A bit like driving a car without a speedometer

With practice you can easily learn to recognize your AGL height via FPV. Just look at the view. 100' looks way different than 400' in your screen. It's not that difficult. It's like judging how fast your driving without looking at the speedometer. You can usually estimate it within 25mph, right? Easy. It's just as easy to know if you're 100' versus 300' by looking at the screen. Teach yourself, it's not hard if your eyes are normal. Estimating within a 100' tolerance is easy with enough practice. It's part of learning how to fly. Make it point to practice fpv visual height recognition. You'll learn it pretty quick.

 

[Rumbaar]

The wind aloft will be similar to what you sense down on the ground but it may be stronger.
If there is no wind aloft, your Phantom in atti mode,

Um, what does that have to do with real-time wind speed and a built in anemometer? Also how does that help, when the drone is 1.5 kms away, over a cliff or at 120m height? I understand, after the fact, you can use tools like HealthyDrones.com or visual cues like you've described, but that of no assistance when out in the field in real-time flight conditions.