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New warning and new MA2 flight behavior confused me!

Mt-Ed

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I'm a new drone pilot, with just about a dozen flights under my belt. Each flight reminds me of when I first started to drive, where it seemed there were so many things to keep track of and manage. Like then, I find myself tensing up while flying, particularly when an unexpected warning or announcement pops up on my screen, which is what occurred during one of my last three flights (used 3 batteries).

I was flying to a place in the forest, an opening of approx. 30yds wide by 50yds long. This opening contains an elk wallow, which is typically a wet (open water) and muddy area, where bull elk come to urinate in this mess, and then proceed to wallow in it! It really turns the lady elk on? Anyhow, I had flown to this place last fall. At that time, I approached the opening the same as this time, flew above tree level til I reached the opening, rotated my gimbal directly down, positioned myself in the center of the opening, and then slowly and carefully descended to examine the details of the wallow. I got low enough at that time to observe the prop wash in the grass that was growing there, and then when I hovered over the 8' pool of water, I easily saw the drone's reflection on the water's surface. I proceeded to maneuver around the clearing before ascending and returning back the the HP.

On the flight I took the other day, I attempted to duplicate my past flight to this opening, and everything was occurring as before, until I was slowly descending into the clearing. As I neared the "ground" I received a written warning on my screen. I do not remember it in detail, and what lingers in my feeble memory was it was indicating that the "ground" surface was unsatisfactory for the sensors. You see, on this trip, there was at least 3 feet of snow where the grass and water was before! To make matters worse, this "ground" was in the shade, so it had NO definition. So "if" the warning was as I seem to recall, this made perfect sense to me, and my solution was to immediately ascend a bit. The warning went away, but I don't remember if it was after I ascended, or just timed out. I have physically been to this "wallow" many many times......to the point that I know where each tree and shrub is, so I brought the gimbal back to 0 degrees, and once again slowly started to descend while watching specific shrubs, and my juxtaposition to them, giving myself some idea of where I was in relation to the snow ground. This time as I was descending, I got a "command" that my drone was going to land, and provided a red dot with an "X" in it with the instructions, "press the "X" if you wish to abort the landing! My anxiety level maxed out because I did not know exactly how close I was to the snow, would the drone shut off after landing, if it did, could I restart it to take off again, or what ever else that might happen for which I had no knowledge of! BTW, I DID NOT want to have to snowshoe back in there to retrieve it either!

I aborted the landing, and then ascended about 20' (based on a reference tree, who's height I know exactly). I then moved a short distance horizontally, and then all of a sudden, I got the "drone is landing" command again! So, again I aborted the command, ascended above tree level, and returned to my HP. I thought I knew what to expect from this point, until I had my drone back in my hand, but oooooooh nooooooo! When I got my drone back to the HP, I was maneuvering for a hand catch landing ( the area has no level places, is very rocky, and on a hill side). I flew the drone just past me, and towards the uphill side, where it was probably between 2 and 3' from the ground. Then it happened again...the "drone is landing" command, "press the button to abort", which I did, then maneuvered over to my outreaching hand and caught it.

So, that whole rambling missive was to, as accurately as I could recall, describe all conditions before I ask:

Has anyone else ever received a "warning" for a ground surface that the sensors were not registering? Was the reason I was getting the "drone landing" command because I had gone so low to the ground, that the algorithm assumed that is what I wanted to do, and was just confirming that process? The only perplexing event regarding the landing command was when I was at least 20' above the ground when I got the 2nd landing command?

I plan to return to this location and do some controlled experimentation. On that day, I had to snowshoe over numerous snow fields to reach the spot I chose for my HP. When I return next time, I plan to choose a HP just a dozen yards from a "representative" snow covered area like the forest clearing, launch my drone, and try to duplicate the events of the other day, by approaching the shaded snow from high above, see if I get the same warning for the unrecognizable surface, and then as I approach the surface, see if I get the landing command again.

I welcome any input from all on here, particularly if you've experienced any of these events. After I get back out and complete my experimentation, I will report back here and update with my findings.......in case anyone else is interested. Thanks so much for listening.......and commenting!!
 

Meta4

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So, that whole rambling missive ...
Yes
Has anyone else ever received a "warning" for a ground surface that the sensors were not registering? Was the reason I was getting the "drone landing" command because I had gone so low to the ground, that the algorithm assumed that is what I wanted to do, and was just confirming that process? The only perplexing event regarding the landing command was when I was at least 20' above the ground when I got the 2nd landing command?
As always, the place to find answers is in your recorded flight data for the relevant flight.
It will likely give clues about what was happening.

Go to DJI Flight Log Viewer | Phantom Help
Follow the instructions there to upload your flight record from your phone or tablet.
That will give you a report of the flight.
Come back and post a link to the report it gives you (even if it looks like an empty report).
Or .. just post the txt file here.
 
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Mt-Ed

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Thanks Meta. I did as instructed, but got an error msg. "Error: The recaptcha challenge failed. If this continues to happen, please contact [email protected]." So, I'll copy the txt file for you here. Wish I could have seen the decoded flight record........
 

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  • DJIFlightRecord_2021-04-03_[09-27-06][1].txt
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Meta4

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Mt-Ed

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I was finally able to access the log. I see there was a forced landing at approx. 13m and then again at 15m into the flight. They both start appro. the same altitude, so I'm wondering, was the drone sensors indicating I was at the "safe" lower limit, and my full down throttle was then forcing the drone to land?
Also, can you please tell me what the black/white dots represent on the map? Two of them show the forced landings, but I don't see what the others represent? Thanks Meta!!
 

Meta4

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Thanks Meta. I did as instructed, but got an error msg. "Error: The recaptcha challenge failed. If this continues to happen, please contact [email protected]." So, I'll copy the txt file for you here. Wish I could have seen the decoded flight record........
Unfortunately warnings and error messages in DJI Fly don't show up well in the Phantomhelp log viewer so I've used Airdata to see them.

The confirm landing mesages appeared at 13:-4 and 15:03.
Both times the VPS was reporting that the drone was less than 3 ft above something and you were holding the left stick down.
Obstacle avoidance stalled your descent to prevent you bumping into what was down there.

Something about whatever was below the drone, didn't appear to be a good landing site to the downward facing sensors.
It asked if you really wanted to continue descending and land the drone.
This is quite normal.
 

Mt-Ed

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Thanks again Meta, I suspect the sensors were having trouble with the snow as it was smooth, without any defects in the surface, and in the shade, which even makes it hard for human eyes to determine where the surface actually is!

Can you please tell me what the black and white dots were in Phantomhelp along the flight path? Also, in PH, is the circular, 1/2 blue indicator on the right, the drone's attitude indicator while in flight?

Thank you very much....
 

Meta4

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Can you please tell me what the black and white dots were in Phantomhelp along the flight path? Also, in PH, is the circular, 1/2 blue indicator on the right, the drone's attitude indicator while in flight?
The dots are a countdown of battery life in 10% increments - 90%, 80%, 70% etc
The circle is the attitude indicator, showing pitch and roll for any line of data that you click on.
 

Holdenfish

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II too have had troubles flying in the winter in the mountains to elk clearings. The snow doesn't provide a very good ground surface for the drone to get recognition I've had this trouble I love flying in the snow but much like smooth water there's no texture for the drone to recognize. The drone had a little trouble. you'll work it out