Estimating height if trees, utility line. Buildings. Hills and other natural features both nearby and distant.

[Kenh6468]

When setting return to home setting the proper altitude is necessary so my Mavic Mini doesn't fly into objects in its flight path while coming home so I'd like to know is there an android phone app that can be used to estimate the height of both close by and distant obects such as trees, buildings, ultility lines, etc. which people like me who aren't good at estimating height can use?

 

[rehkram]

My thinking is climb to the height where the FPV view shown on your device is dead level with the top of highest obstacle. Then add, for example, 33% to the height shown on the display and set that as your RTH altitude. You don't need an app for that.

So if the top of the highest tree is 100 feet, multiply 100 x 1.33 = 133 feet.

 

[pinballwiz86]

To be safe just set it for 300 feet and forget it.

UNLESS—you’re flying somewhere with crap above the drone. Then set it to hover in place.

 

[lannes]

I use the method of looking for nearby building and counting the stories, if I can see 4 stories for example I know it's about 16m high.
A storey is about 4m roughly

 

[slup]

When setting return to home setting the proper altitude is necessary so my Mavic Mini doesn't fly into objects in its flight path while coming home so I'd like to know is there an android phone app that can be used to estimate the height of both close by and distant obects such as trees, buildings, ultility lines, etc. which people like me who aren't good at estimating height can use?

As already said ... use your drone.

Made a post back in March about this, have included it here below with an example made in Google Earth to show how to do it.

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[AMann]

Theodolite is a good IOS app for measuring objects on an iPhone, I believe there are droid versions of it too, try searching for theodolite pro.

 

[AMann]

As already said ... use your drone.

Made a post back in March about this, have included it here below with an example made in Google Earth to show how to do it.

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I can see how this would work well if the horizon is near the same elevation as you are, but looking at that second image, I wonder what happens if that horizon line is a high hill or mountain? In that case, wouldn’t one get tricked thinking that since the tree line in the foreground is below the horizon, they are flying higher than the trees?

 

[slup]

I can see how this would work well if the horizon is near the same elevation as you are, but looking at that second image, I wonder what happens if that horizon line is a high hill or mountain? In that case, wouldn’t one get tricked thinking that since the tree line in the foreground is below the horizon, they are flying higher than the trees?

It's all about judging & common sense, you will never be 100% sure without actually fly to the obstacle & check. But granted ... gauge a height with the drone towards the horizon requires a reasonably free horizon. Adding those extra meters is what should take care of possible gauging errors. Besides all this, a proper flight plan is needed so you know that something unforeseen high never will be in between the HP & the AC anywhere in the flight path.

 

[Phil56]

Hi all. New owner of a mini and super impressed as I use it for our solar projects to view daily progress.
With regards the tree height there is an easy solution. Use a pencil while standing away from the tree with your arm attached out in front of you and size the tree height with the pencil length where the base is your thumb and the tip the tree top. Turning the pencil 90 degrees pick the spot where the tip ends and your thumb lined up at the base. Pace the distance from the tree base and you will have a reasonable idea of the height. The further back you go the more accurate you will be. Rule of thumb again.

 

[zeusfl]

To be safe just set it for 300 feet and forget it.

UNLESS—you’re flying somewhere with crap above the drone. Then set it to hover in place.

I do exactly the same thing. Where i fly the limit is 400 ft. I always set to 300 personally and I am sure that I have plenty clearance.

 

[Tolly]

I have Dronelink and even if I am not going to use it to fly a pre planned mission I can use it to set up a flight over the area I am going to then run a virtually mission in google earth. That way I can see the altitude I need to clear all obstacles in the area. Of course, that is a useless option if you need something on spec in the field.

 

[macfawlty]

I generally like to fly lower for more cinematic video. There are typically some trees taller than the rest I need to watch for, or I'm traveling along a ridge with undulating contours. A reconnaissance flight over the area and estimation from camera view described above is a good start. I don't like to set the RTH at max height due to wind at higher altitudes.

 

[Bsnyder]

As already said ... use your drone.

Made a post back in March about this, have included it here below with an example made in Google Earth to show how to do it.

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It makes sense, what you are saying and the pictures you have shown, but Dose the angle of the gimbal effect what you are seeing and the height you need to fly to clear everything.
Thanks Bob

 

[TreeHugger]

Hey -
Before you complain about the cost, note that it comes with a really nice cleaning cloth. ?

Nikon Forestry Pro II Laser Rangefinder

 

[Camino Ken]

It makes sense, what you are saying and the pictures you have shown, but Dose the angle of the gimbal effect what you are seeing and the height you need to fly to clear everything.
Thanks Bob

Yes, the gimbal need to be at 0deg (default horizontal). Also it helps to turn on the grid lines to help judge the middle of the frame.

 

[Bsnyder]

Yes, the gimbal need to be at 0deg (default horizontal). Also it helps to turn on the grid lines to help judge the middle of the frame.

Thanks for the information

 

[Ol' Sparky]

Sorry if this is a stupid question...I fly a Spark and a M2Z using the Go4 app. Doesn't this apply to a mini and the fly app?

 

[zeusfl]

Sorry if this is a stupid question...I fly a Spark and a M2Z using the Go4 app. Doesn't this apply to a mini and the fly app?
View attachment 114552

No. The mini only have 1 sensor and is in the bottom of the aircraft. Can detect if something is wrong when landing. Can not avoid any obstacle front, back, left, right or top for the lack of sensors.

 

[Ol' Sparky]

No. The mini only have 1 sensor and is in the bottom of the aircraft. Can detect if something is wrong when landing. Can not avoid any obstacle front, back, left, right or top for the lack of sensors.

Thanx for the confirmation. One of the costs of staying under 250g I guess

 

[Kenh6468]

It makes sense, what you are saying and the pictures you have shown, but Dose the angle of the gimbal effect what you are seeing and the height you need to fly to clear everything.
Thanks Bob

Can't view the attachments you've included in this post. When I click on each one it takes me back to this screen and post.