I think it would have been lower than that at WP16. Takeoff elevation was 57 m MSL. Height above that at WP16 was 2 m, giving 59 m MSL. Ground elevation at WP16 is 53 m, putting it 6 m (~ 20 ft) off the ground.
Phantom 3 drone down
- Thread starter rickatom
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I think it would have been lower than that at WP16. Takeoff elevation was 57 m MSL. Height above that at WP16 was 2 m, giving 59 m MSL. Ground elevation at WP16 is 53 m, putting it 6 m (~ 20 ft) off the ground.
Meta4
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The differences are due to the starting point height.
I took that from Google Earth as 205 ft and Wpt 16 as 177 ft or -28 ft for the Phantom + 6 feet for the waypoint height = 34 ft agl.
With either number, it wouldn't allow enough clearance for the sort of trees there.
This thread is like reading a good mystery only to find the last 3 pages are missing.
Maybe you can form a local droners posse to help search.
I sure hope you find it.
crasher
Maybe you can form a local droners posse to help search.
I sure hope you find it.
crasher
The differences are due to the starting point height.
I took that from Google Earth as 205 ft and Wpt 16 as 177 ft or -28 ft for the Phantom + 6 feet for the waypoint height = 34 ft agl.
With either number, it wouldn't allow enough clearance for the sort of trees there.
I agree - it's certainly too low at WP16 - street view shows the trees are quite tall. I see where the discrepancy in the altitude comes from - you used the mission end point (205 ft MSL) as the reference elevation while I used the mission start point (188 ft MSL). I think that the altitude reference will be the start point.
i have flown around my home taking estimates. Trees right around the area are about 125 ft.
I had binoculars today. Still hard to tell.
You guys seem pretty certain it should be there. I will look again. My son looked from Wp 17 back. He said i was pretty thick. Smaller trees and bushes growing under the fairly bare tall trees.
I appreciate you guys helping me out.
We love these puzzles. Now it's up to you to compare all our modeling with reality.
Note also that if the trees between WP11 and WP12 are also that high then you will need to consider that area - the programmed altitude AGL was only around 70 ft there.
In fact if you have 125 ft trees around then your 41 m (134 ft) relative altitude was inadequate over much of the track. But those would be huge trees - are you sure they are that high?
I am probably not off by much. Alot of pines and gum trees around here.
Google Earth DEMs are not bad in my experience. Unlike the weather, ground elevation is pretty constant on our timescales.
In that case, why did you think that a flight altitude of 134 ft was adequate for the mission?
Keep at it Rick. I'm sure I'm not the only 'lurker' that's pulling for ya from the sidelines. This has become a great mystery. 
honestly, I flew a few trial mission around the house and footage seemed good. No rhyme or reason. I guess another lesson learned.
I would recommend always allowing at least a 50 ft buffer above any anticipated obstacles. If you are unsure of the height of obstacles on the programmed track then I'd go for a 100 ft buffer above your best guess.
Though all these scenarios seem realistic, Is there anything else that could have gone wrong?
When I took off, I loaded the flight plan. It loaded, and took off. It seemed not long after I lost signal, and camera scrambled. I waited ,for quite a while. Not sure how long. I walked around towards front of house to higher ground. My cellphone lost power. I changed batteries in cell, once I got it powered up, I was totally lost. I hit return home. but if no reception, it wouldnt have worked anyway.
Though drone should have continued mission regardless, right? I never turned off controller.
When I took off, I loaded the flight plan. It loaded, and took off. It seemed not long after I lost signal, and camera scrambled. I waited ,for quite a while. Not sure how long. I walked around towards front of house to higher ground. My cellphone lost power. I changed batteries in cell, once I got it powered up, I was totally lost. I hit return home. but if no reception, it wouldnt have worked anyway.
Though drone should have continued mission regardless, right? I never turned off controller.
Correct. A Litchi mission does not require connection to the RC once it has started.
just wanted to make sure nothing during this time would have sent it mixed signals or something.
