Drones at Height.

braveheart · Aug 8, 2018

I would like to ask for some help on drones for a novel I am writing.

My "hero" is looking for a cave in the White Mountains of Crete where his grandfather hid something while on the run during the Second World War. He is no mountaineer but can get to a plateau at 4000 feet in a 4 x 4. The cave is somewhere above him, around the 5000 feet mark.

Would it be feasible for him to fly a drone with a camera attached at this height to search the surrounding mountains for the cave??

I know nothing about drones!!

Meta4 · Aug 8, 2018

braveheart said:
Would it be feasible for him to fly a drone with a camera attached at this height to search the surrounding mountains for the cave??

Yes ... DJI drones account for >70% of all ready-to-fly drones sold.
They are hardwired to fly no higher than 1500 feet above their launch point.

WV. Rootman · Aug 8, 2018

There is a quad copter with four motors. And there are drones that fly like regular planes. It seems that most people like to fly the quad copters because they can hover in one place. They also have gimbals which allowed for the cameras to look down and look up 30° pass the Horizon. A problem with the cameras for looking for things is that the cameras are wide angle so everything seems further away. So to see something well you have to get in close. Looking for a cave could be difficult because of trees rocks obstructions in the winds that whip around the rocks. Winds up that high can play havoc with a drone. If you fly with the win you can go rather fast and far away. But coming back and be a big problem. Let’s say the wins 30 miles an hour and your drone does 32 miles an hour. It’ll come back quite slowly and may not get back before the battery runs out. Or if it doesn’t have enough power it just keeps going away from you till the battery goes dead and crash lands.
Another problem with flying drones is large birds of prey. if you get anywhere near their nest you’re likely to get a attacked very quickly. With eagles they just may come over an attack you for no reason or for territorial reasons. Eagles aren’t affected by the props on the drones at all I can carry the drone off and place it on the ground. Drones have been recovered that way. Drones are also very noisy and Can and startle animals .
I had so much to say. I just spoke verbally into the laptop. I hope it all comes out OK

braveheart · Aug 8, 2018

Thanks very much for these replies, guys. It makes me understand how much I don't know about drones! The thing going for my idea for my novel is that frequently, it is very hot and absolutely still in the White Mountains of Crete. So it seems to me that while noting the point about wide-angle lens, a drone could still work in searching for the cave in still conditions. There are simply no trees above the 4000' level, so that is not a problem. But I hadn't thought about large birds of prey of which there are many in these mountains. But I will now!

Your assistance is much appreciated.

Nightwolf · Aug 8, 2018

Can't go inside the caves or you will lose GPS and reception and thus crash the drone. It is important to maintain line of sight in order to maintain communications with the drone. If you lose communication with the drone but it still has GPS it will return home. If you lose GPS it does not know where home is so if you still have Communication you can fly it manually. If you lose both you lose the drone.

All of this is in reference to DJI drones. I'm relatively new here so i welcome corrections to any of my statements

braveheart · Aug 8, 2018

Nightwolf said:
Can't go inside the caves or you will lose GPS and reception and thus crash the drone. It is important to maintain line of sight in order to maintain communications with the drone. If you lose communication with the drone but it still has GPS it will return home. If you lose GPS it does not know where home is so if you still have Communication you can fly it manually. If you lose both you lose the drone.

All of this is in reference to DJI drones. I'm relatively new here so i welcome corrections to any of my statements

Thanks, Nightwolf: gotcha! In my scenario, the drone would NOT enter the cave. It would locate the cave and my Protagonist would go to the cave on foot and enter it in person. But thanks again.

Meta4 · Aug 8, 2018

braveheart said:
it is very hot and absolutely still in the White Mountains of Crete. ...a drone could still work in searching for the cave in still conditions.

The drones can easily deal with wind.
It's just strong winds that are an issue.

tcope · Aug 8, 2018

Meta4 said:
Yes ... DJI drones account for >70% of all ready-to-fly drones sold.
They are hardwired to fly no higher than 1500 feet above their launch point.

1640 feet above take off.

With The Birds · Aug 9, 2018

tcope said:
1640 feet above take off.

1500 was probably close enough, where we use metric we just multiply by 3 for a rough calc. it’s 1639.34426 ft to be precise about it. We can probably assume launch and takeoff to be the same point.

happydays · Aug 9, 2018

You could cover a lot of ground with the phantom to eliminate much of the terrain. You might have to make a number of reconnaissance flights so factor that in. Sounds like a good project.

Technical Bob · Aug 9, 2018

braveheart · Aug 11, 2018

Hi Technical Bob

Is it okay to ask you a couple of questions about filming from a drone? I am not at all technical nor IT savvy!

braveheart · Aug 11, 2018

happydays said:
You could cover a lot of ground with the phantom to eliminate much of the terrain. You might have to make a number of reconnaissance flights so factor that in. Sounds like a good project.

Could you please explain in non-techie English what you mean by "with the phantom"?? Thnaks!

ribjig · Aug 11, 2018

Phantom = drone model
if your character is also drone newbie,
it would not be unusual after finding cave,
which he would see on remote control
tablet, to not know that trees & rock can
block signal & drone would crash into
tree or rocky outcrop near cave...

Mike z. · Aug 11, 2018

braveheart said:
Hi Technical Bob

Is it okay to ask you a couple of questions about filming from a drone? I am not at all technical nor IT savvy!

Protagonist would need extra batteries for search over 25min. Maybe a inverter in vehicle to charge battery.

apprentice · Aug 11, 2018

braveheart said:
Thanks, Nightwolf: gotcha! In my scenario, the drone would NOT enter the cave. It would locate the cave and my Protagonist would go to the cave on foot and enter it in person. But thanks again.

Are you talking about the mountains close to Samaria gorge? It is a very deserted area with no trees. I've been there several times as a photographer for a tourist agency.

For my opinion you would hardly see a cave from the air while flying. You should be real close but I really like to avoid flying close to the terrain while flying in the mountains. But I do lots of reconnaissance flights with my Phantom. I always research the area with google maps in advance. I print a map of the area and mark the points of interest in advance. Then I make a reconnaissance flight and record a video. When back home I examine the recordings on my computer because I have a much bigger monitor at home than the tablet I use for flying has.