Litchi waypoint altitude transition

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Hi,
I have been loving using Litchi with my Phantom 4 Advanced and my missions around the house have been going well. I just took it out on the farm (what I bought it for) and sent it on a hilly mission that I had carefully planned and double checked with Google Earth.

It seems it disconnected and crashed pretty shortly thereafter. It seemed too low just before it disappeared.

I'm thinking either Google Earth altitudes are out by 10m or so OR it goes to each waypoint and then changes altitude (and I had assumed a straight line between the two). Can anybody help? This would help me decide where to search.

I will go and hunt for it in the gorse in the morning. I had so much work planned for it and it was going so well!
 

Meta4

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I'm thinking either Google Earth altitudes are out by 10m or so OR it goes to each waypoint and then changes altitude (and I had assumed a straight line between the two).
Google Earth heights are approximate and are for the terrain, not any vegetation above the terrain.
Litchi makes a smooth transition between altitudes.
Can anybody help? This would help me decide where to search.
If you can share your Litchi mission details someone clever might be able to look into it and help suggest a likely crash location.
 
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Thank you, that helps and gives me a few places to start. The mission seems stupidly ambitious now, it wasn't a good place to have it all go wrong.


Google Earth heights are approximate and are for the terrain, not any vegetation above the terrain.
Litchi makes a smooth transition between altitudes.

If you can share your Litchi mission details someone clever might be able to look into it and help suggest a likely crash location.[/QUOT
 

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Here is a quick picture
mjlp.jpg

Rod
 
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RodPad

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Try to save your mission as a KML 3D path, the load it in google earth pro.

Rod
 
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Try to save your mission as a KML 3D path, the load it in google earth pro.

Rod
Yes, I did that when I planned it...hence my unwarrranted confidence as I started the misson. I also carefully made sure I launched it slightly above Waypoint 1 and that Waypoint 1 was pretty much at the top of the mission.

The ground is really rough, so I'm guessing it met ridges in places it wasn't expecting them :-(
 
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Here is a quick picture
View attachment 103204

Rod
That's a Litchi screen?
Yes, I did that when I planned it...hence my unwarrranted confidence as I started the misson. I also carefully made sure I launched it slightly above Waypoint 1 and that Waypoint 1 was pretty much at the top of the mission.

The ground is really rough, so I'm guessing it met ridges in places it wasn't expecting them :-(
 

RodPad

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Well I see now why your focused between wp1 and wp3.
I made some modifications to give me a better look.
Mission Hub - Litchi

Questions,
How far were you away from launch to wp1?
Where did you loose signal?
Can you upload your log from your mobile device to here?
DJI Flight Log Viewer - Phantom Help
Then share your log with us, copy the results URL back here.

Then I'm sure some others will join in on your hunt. ;)

Rod
 
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RodPad

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@Tony Micle,
Google Earth view of his mission.

Rod
 
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Did you ever resolve the issue. ..The 3d Google view looks like it would be fine
 
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Here is the data, but as you will see it doesn't last long. I should have started it from a ridge where I was going to be able to see it for a while. Now full of gorse prickles, but will go and look tomorrow again between 2 and 3, but this time take a scrub cutter...

 
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Okay .. I was looking into doing away missions with this app. And happened across the thread. . And spooked me .. so you reckon you didn't get to the 100 feet Above Ground because of higher than expected vegetation
 
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What is the max height of the trees/scrub along the route. For me Google is pretty accurate in ground heights, but it will have no clue as to tree heights, etc. Starting out, I would use the GO app to check surrounding tree heights plus a significant flight altitude above them.
 
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Okay .. I was looking into doing away missions with this app. And happened across the thread. . And spooked me .. so you reckon you didn't get to the 100 feet Above Ground because of higher than expected vegetation
Litchi is great. This was definitely my fault. Lessons learnt:
- If the drone is going out of sight have a plan for what to do if it all goes wrong, it is a horrible feeling when it doesn't come back and searching is futile (so far!)
- Be very careful in rough terrain and get to know it first - go high and slow
- Google Earth is great, but having bashed around the hill a lot now, I'm not sure the ridges are in exactly the right places and in steep terrain that really matters
- Allow for trees to be bigger than you think
- Don't rush. I really wanted this footage for a project and so pushed ahead before I should have
 
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What is the max height of the trees/scrub along the route. For me Google is pretty accurate in ground heights, but it will have no clue as to tree heights, etc. Starting out, I would use the GO app to check surrounding tree heights plus a significant flight altitude above them.
Higher than I thought :-( there are some individual pine trees and the dark green trees to the north-west are also pines, but I don't think it ever got that far. The rest is low scrub
 
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I did a simple straight-line mission that flew into a hedge (my missions are all for real-restate and most are about 2-5 metres above the ground).
Litchi's response to my query (the flight should have cleared the hedge easily) was that heights above sea level can be out by 30 feet. It didn't satisfactorily answer my question because if that was the cause, the start position should have been equally wrong.
So I'm not a big help! :)
 
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65' AGL?? Most trees are 80' and some pines can reach 110-120' I always fly at a minimum of 150' and even then the trees appear very close.
 
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Hi,
I have been loving using Litchi with my Phantom 4 Advanced and my missions around the house have been going well. I just took it out on the farm (what I bought it for) and sent it on a hilly mission that I had carefully planned and double checked with Google Earth.

It seems it disconnected and crashed pretty shortly thereafter. It seemed too low just before it disappeared.

I'm thinking either Google Earth altitudes are out by 10m or so OR it goes to each waypoint and then changes altitude (and I had assumed a straight line between the two). Can anybody help? This would help me decide where to search.

I will go and hunt for it in the gorse in the morning. I had so much work planned for it and it was going so well!

Litchi Learning Curve:
My first Litchi flight was a waypoint mission over 100 acres and a lake. I had planned it in Mission Hub in the comfort of my home. The property looked flat from satellite maps (duh). I did not think of Google Earth. My Waypoint mission started from a 400 ft panorama and went to waypoint 2 at 125 ft by the lake, then waypoint 3 at 85 feet and by the lake shore. On the way to WP 3, I lost video signal and then RC signal and the last thing I saw was a tree, way higher than the drone. I was 1/2 mile from the lake and started my hike to try and find my Mavic Pro in the trees. 200 yards up the trail, I got a video signal again. Again all I could see was a pine tree. I finally angled the camera down and saw a road. The Mavic was hovering above the road where my truck was parked but up close to a pine tree and the obstacle avoidance had stopped it.
My stomach stopped aching and I landed my drone and said a prayer of thanks.
It turned out a ridge was between me and WP 3 and I didn't know it since I hadn't checked Google Earth terrain map.
The Mavic had completed it's programmed flight, took beautiful video and when the mission ended and it had no signal, it returned to home and hovered. It missed home by 20 feet and ended up against a tree.
I had not even accounted for the difference in tree height from ground height.
I was SO lucky.

A couple of weeks later. flying my P4P (see, I know this is a Phantom forum:)), on a 200 acre parcel, I had added 100 feet to each waypoint altitude to account for trees; I thought.
1/2 way through the mission, while watching the video monitor, I saw a tree higher than the drone go by and hit the abort button and shot straight up. Since the waypoint mission was still on the monitor, I finished flying the mission manually and got good footage.
Back home and checking the terrain maps again, if I drew a straight line between the 2 waypoints where I had the tree problem, I saw it passed over a ridge at an altitude lower than the possible tree height. I had programmed a waypoint 100 feet over the river to 100 feet over a distant ridge not counting on a straight line between the two crossing too low over a ridge in between.
I just shot another property where the measured tree height was up to 130 feet. My 100 foot "guess" would have had me in trees again.
So what have I learned? Trees are higher than I thought and I can't just trust Litchi Mission Hub altitudes to be safe. Maybe that sounds dumb, but I had to learn it by making mistakes.
I don't know any solution to just using Litchi Mission hub to plan in advance without doing a flying survey of the property once you get on site to see if your plan makes sense altitude and obstacle wise.
 
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