Three fatal mistakes when flying over water!

[Squidinc]

Hi all,
A great many of us fly over water at some point with our flights. I came across this interesting YouTube video on Ted Nemeth's channel and thought it was worth sharing.

 

[Meta4]

I don't think the video has any useful information to help you fly over water.
You commonly hear that the downward facing sensors get confused over water.
The video guy demonstrates another common problem.
Some drone flyers are confused about how their drones and the their sensors work over water.

He demonstrates misunderstanding some basics of how the drone works and is influenced by the common myth that drones "get confused" over water and rather than analysing his incidents to see what actually happened, he's just going with the myth and perpetuating it.

He talks about having the drone out of visual range and having to rely on what the controller is telling him.
"The controller can tell you that you are 10 metres up but the drone is only one metres high.
This shows a complete misunderstanding of what the controller does and doesn't tell you.
It doesn't give you any information about how high the drone is above the water.
But if you rely on it, thinking it does, you are putting your drone at risk.

He suggests that the visual sensors somehow measure height of the drone - they don't.
The visual sensors are for horizontal positioning, not vertical measurement.

Later on he says something that indicates he thinks GPS reception affects the drone's ability to maintain height - it doesn't.

 

[kevguy]

I think the title of the video is improper. The video is more of his 3 personal opinions when flying over water.

 

[JeffreyS]

Junk. I fly over water all the time. No different than flying anywhere else. Just fly properly.

 

[twickers14]

I’ve never had a problem but I am more nervous than normal if I am over water. So I just keep my eye on the drone and the controller/phone screen to see if there any warning signs. The guy in the vid is quite engaging but I would not know about the capabilities of the sensors, the guys and gals here on the Forum know much more about that, including our friend Squidinc who’s work I much enjoy.

 

[MS Coast]

Lots of techno-babble and conjecture. Not much science or engineering.

 

[Droning on and on...]

It doesn't give you any information about how high the drone is above the water.

Not to detract from an absolutely proper trashing of a crap video, I think you forgot about the ultrasonic or IR ranging sensors that, when closer than 10m (ultrasonic) or 15m (IR ToF) the drone does measure an absolute height above the surface below it, and display it in the bottom left of the display in red.

A minor nit.

 

[Richard R]

I don't think the video has any useful information to help you fly over water.
You commonly hear that the downward facing sensors get confused over water.
The video guy demonstrates another common problem.
Some drone flyers are confused about how their drones and the their sensors work over water.

He demonstrates misunderstanding some basics of how the drone works and is influenced by the common myth that drones "get confused" over water and rather than analysing his incidents to see what actually happened, he's just going with the myth and perpetuating it.

He talks about having the drone out of visual range and having to rely on what the controller is telling him.
"The controller can tell you that you are 10 metres up but the drone is only one metres high.
This shows a complete misunderstanding of what the controller does and doesn't tell you.
It doesn't give you any information about how high the drone is above the water.
But if you rely on it, thinking it does, you are putting your drone at risk.

He suggests that the visual sensors somehow measure height of the drone - they don't.
The visual sensors are for horizontal positioning, not vertical measurement.

Later on he says something that indicates he thinks GPS reception affects the drone's ability to maintain height - it doesn't.

@Meta4 thanks to you and other experts who spend considerable time reading and replying to posts, this forum is my go to source from valuable drone education.

 

[Squidinc]

I don't think the video has any useful information to help you fly over water.
You commonly hear that the downward facing sensors get confused over water.
The video guy demonstrates another common problem.
Some drone flyers are confused about how their drones and the their sensors work over water.

He demonstrates misunderstanding some basics of how the drone works and is influenced by the common myth that drones "get confused" over water and rather than analysing his incidents to see what actually happened, he's just going with the myth and perpetuating it.

He talks about having the drone out of visual range and having to rely on what the controller is telling him.
"The controller can tell you that you are 10 metres up but the drone is only one metres high.
This shows a complete misunderstanding of what the controller does and doesn't tell you.
It doesn't give you any information about how high the drone is above the water.
But if you rely on it, thinking it does, you are putting your drone at risk.

He suggests that the visual sensors somehow measure height of the drone - they don't.
The visual sensors are for horizontal positioning, not vertical measurement.

Later on he says something that indicates he thinks GPS reception affects the drone's ability to maintain height - it doesn't.

Thanks @Meta4. You make some very valid points.

 

[Squidinc]

Lots of techno-babble and conjecture. Not much science or engineering.

Agree.

 

[Squidinc]

I’ve never had a problem but I am more nervous than normal if I am over water. So I just keep my eye on the drone and the controller/phone screen to see if there any warning signs. The guy in the vid is quite engaging but I would not know about the capabilities of the sensors, the guys and gals here on the Forum know much more about that, including our friend Squidinc who’s work I much enjoy.

Thanks @twickers14 for your kind remarks. I think @Meta4 has summed up this “over water” video pretty well.

 

[Yorkshire_Pud]

I don't think the video has any useful information to help you fly over water.
You commonly hear that the downward facing sensors get confused over water.
The video guy demonstrates another common problem.
Some drone flyers are confused about how their drones and the their sensors work over water.

He demonstrates misunderstanding some basics of how the drone works and is influenced by the common myth that drones "get confused" over water and rather than analysing his incidents to see what actually happened, he's just going with the myth and perpetuating it.

He talks about having the drone out of visual range and having to rely on what the controller is telling him.
"The controller can tell you that you are 10 metres up but the drone is only one metres high.
This shows a complete misunderstanding of what the controller does and doesn't tell you.
It doesn't give you any information about how high the drone is above the water.
But if you rely on it, thinking it does, you are putting your drone at risk.

He suggests that the visual sensors somehow measure height of the drone - they don't.
The visual sensors are for horizontal positioning, not vertical measurement.

Later on he says something that indicates he thinks GPS reception affects the drone's ability to maintain height - it doesn't.

@Meta4 , if you haven't already, it might be useful if you responded in the comments section on the actual youtube as well.

 

[singram]

Junk. I fly over water all the time. No different than flying anywhere else. Just fly properly.

Same. I pretty much have a river in my backyard that runs thru the surrounding 3 'burbs, so my flights a almost exclusively over water. In the 2 years I've been flying both drones, no Bermuda Triangle incidents or sea monster sightings to report.

 

[kevguy]

Same. I pretty much have a river in my backyard that runs thru the surrounding 3 'burbs, so my flights an almost exclusively over water. In the 2 years I've been flying both drones, no Bermuda Triangle incidents or sea monster sightings to report.

Have you seen the Loch Ness Monster? I hear he likes to eat drones…

 

[thepushercg]

with the Tennessee river 2 miles from me it makes a prime spot to fly. done so many years, lost a few birds because of stupidity, mainly bebop 2s maxing out the battery's. however not any problems with dji birds. its just a natural attraction

Have you seen the Loch Ness Monster? I hear he likes to eat drones…

to fly over water for me.

 

[singram]

with the Tennessee river 2 miles from me it makes a prime spot to fly. done so many years, lost a few birds because of stupidity, mainly bebop 2s maxing out the battery's. however not any problems with dji birds. its just a natural attraction


to fly over water for me.

Its also a very wise location to fly IMO. Almost like a free pass(within reason)- no people to worry about flying over and nobody bitching and moaning about you flying over their property.

 

[tls3601]

Thanks @twickers14 for your kind remarks. I think @Meta4 has summed up this “over water” video pretty well.

Erring on the safe side and good old common sense should always rule. I have often wondered just how accurate my height and distance indicators are, once again line of sight

 

[Meta4]

Erring on the safe side and good old common sense should always rule. I have often wondered just how accurate my height and distance indicators are, once again line of sight

Your screen display of distance is very accurate (to within 2 or 3 feet) as it comes from GPS.
Your screen height comes from measurements of air pressure and can be +/- 10 feet or so over the duration of a flight.
You also have to remember that the displayed height is relative to the height of the launch point too.

 

[tls3601]

Your screen display of distance is very accurate (to within 2 or 3 feet) as it comes from GPS.
Your screen height comes from measurements of air pressure and can be +/- 10 feet or so over the duration of a flight.
You also have to remember that the displayed height is relative to the height of the launch point too.

And of course your launch point is GL, so everything above it is AGL. Didn’t know air pressure can throw off accuracy of flight level by plus or minus 10’. Thanks.

 

[Meta4]

And of course your launch point is GL, so everything above it is AGL.

It's not clear from your reply that you realise that your screen display of height is not showing you the height of the drone above ground level. It's showing the height relative to the height of the launch point.
How high the drone is relative to the launch point has no relation to the AGL height of the drone, unless you are flying over a flat, level landscape.

Didn’t know air pressure can throw off accuracy of flight level by plus or minus 10’.

And sometimes even more.