Regardless, any unintended height fluctuation over water should not be more or less than over land if flying normally because it's the barometer controlling the altitude, not any of the vision sensors. So you would leave the same buffer you are comfortable with when flying over any other surface, the only difference being that if it goes down, it's worse over water, so it's probably best practice to air on the side of caution.
Question about flying over water and diving
- Thread starter dwolfe002
- Start date
Regardless, any unintended height fluctuation over water should not be more or less than over land if flying normally because it's the barometer controlling the altitude, not any of the vision sensors. So you would leave the same buffer you are comfortable with when flying over any other surface, the only difference being that if it goes down, it's worse over water, so it's probably best practice to air on the side of caution.
mikemoose55
Well-Known Member
dwolfe
One thought you may look into.
I saw a video on youtube that I remembered last night. It was a DJI tutorial on calibrating the forward and downward sensors.
Think about looking into the DJI web in the mean time here is a youtube vid on the same subject with a Phantom but the gig is the same with a Mavic. You will need to get hooked up with DJI Assistant2 or whatever it is call to operate through your PC or Mac
mikemoose55
One thought you may look into.
I saw a video on youtube that I remembered last night. It was a DJI tutorial on calibrating the forward and downward sensors.
Think about looking into the DJI web in the mean time here is a youtube vid on the same subject with a Phantom but the gig is the same with a Mavic. You will need to get hooked up with DJI Assistant2 or whatever it is call to operate through your PC or Mac
I watched that a couple of weeks ago but I'm not having any sensor errors so I didn't think I would need to. I believe the front sensors will me doing most or all the work. I don't really know if any of the bottom sensors work while moving fairly quick, but something is lifting the Mavic up and in place when the front sensors detect the ground and stop me . It seems that it is only about a foot or so but something is making it ascend a little which is a good problem for me to have. Thanks.
Take care and happy flying!
STUFF2C
Well-Known Member
I fly over water a lot! After losing my drone to a unexpected splash down, I would suggest some sort of recovery system like the
I dont plan to fly over water much any more without one.
My.02
My.02
I don't think anything would do me any good. Saltwater will ruin just about any electronics and metal. I had a splashdown on land yesterday so I have changed my plans of flying a foot over the water. How high were you flying?
STUFF2C
Well-Known Member
After losing my drone in a lake in my backyard... recovery would just make me feel better 
My case is in the hands of DJI right now. According to the data it may be a warranty claim. I was at approximately 100' then an uncontrollable splashdown.
I thought I may have caused it myself somehow... the data shows a different set of circumstances.
My case is in the hands of DJI right now. According to the data it may be a warranty claim. I was at approximately 100' then an uncontrollable splashdown.
I thought I may have caused it myself somehow... the data shows a different set of circumstances.
Ok, Here is some video of my tests a couple of days ago. It looks like when I put in the clips they went in backwards . So the front is the back, the back is the front and the middle stayed where I thought it was. That ought to clear that up. It's my first time using a video editor and I just downloaded the first free one that I found. They didn't tell me the advertisement would be there until I started to render the video. Video editing is a first test also. Anyway I hope all this works because uploading files to a forum is also a first test. Hoping for a trifecta.
Well, that didn't work. I tried to attach the video and it told me it was not a valid file extension. It's in MP4 format. Anybody have any ideas?
Well, that didn't work. I tried to attach the video and it told me it was not a valid file extension. It's in MP4 format. Anybody have any ideas?
kilomikebravo
Well-Known Member
DWolfe: These videos, even the shorter clips, are very large files as you've no doubt seen. Consequently, the folks who run this forum don't have the square miles of servers that YooToob/Google have and thus, cannot handle the zillions of uploads us crazy droners create. 
Therefive, you have to upload your clips to one of the video streaming sites like YT or Vimeo and then, grab the link for your clip and post that here. If you look at the other semi-thumbnails of videos folks post, you'll almost always see either YouTube or Vimeo at the bottom.
Do some searching on YT for the best rendering options for the various YT resolutions which, as others have stated, are highly-compressed and while generally of good quality, they will not look as good to the eye compared to playing the clip natively on a 4k display or TV.
Hope that helps and don't hesitate to ask more questions on the subject, most of us were where you are at one time or another. But, it does help us if you do a little investigating on your own by searching topics on here first before you ask questions since it is very rare for someone to ask a question that hasn't already been answered.
Hang in there and be as patient as you can. There are about a million things to think about when you fly one of these amazing gadgets AND shoot top-notch videos and stills while you're at it. Practice and staying up with the forum posts is the best advice I can give.
Therefive, you have to upload your clips to one of the video streaming sites like YT or Vimeo and then, grab the link for your clip and post that here. If you look at the other semi-thumbnails of videos folks post, you'll almost always see either YouTube or Vimeo at the bottom.
Do some searching on YT for the best rendering options for the various YT resolutions which, as others have stated, are highly-compressed and while generally of good quality, they will not look as good to the eye compared to playing the clip natively on a 4k display or TV.
Hope that helps and don't hesitate to ask more questions on the subject, most of us were where you are at one time or another. But, it does help us if you do a little investigating on your own by searching topics on here first before you ask questions since it is very rare for someone to ask a question that hasn't already been answered.
Hang in there and be as patient as you can. There are about a million things to think about when you fly one of these amazing gadgets AND shoot top-notch videos and stills while you're at it. Practice and staying up with the forum posts is the best advice I can give.
The purpose of the GetterBack in my view is no so much to get a working drone back (though you can always hope) but to get the drone back so it can be sent in for DJI Care if you have that....
That makes good sense. I don't have DJI Care and would just figure that if I go into the water the drone is gone. I don't think any of it will be any good to me except maybe the sd card. One thing I will do is take full responsibility for any crazy situations I may put myself in. Now for over land flights I have considered getting something to help me track it if it should get lost in the forest.
Take care and Happy Flying!
DWolfe: These videos, even the shorter clips, are very large files as you've no doubt seen. Consequently, the folks who run this forum don't have the square miles of servers that YooToob/Google have and thus, cannot handle the zillions of uploads us crazy droners create.
Therefive, you have to upload your clips to one of the video streaming sites like YT or Vimeo and then, grab the link for your clip and post that here. If you look at the other semi-thumbnails of videos folks post, you'll almost always see either YouTube or Vimeo at the bottom.
Do some searching on YT for the best rendering options for the various YT resolutions which, as others have stated, are highly-compressed and while generally of good quality, they will not look as good to the eye compared to playing the clip natively on a 4k display or TV.
Hope that helps and don't hesitate to ask more questions on the subject, most of us were where you are at one time or another. But, it does help us if you do a little investigating on your own by searching topics on here first before you ask questions since it is very rare for someone to ask a question that hasn't already been answered.
Hang in there and be as patient as you can. There are about a million things to think about when you fly one of these amazing gadgets AND shoot top-notch videos and stills while you're at it. Practice and staying up with the forum posts is the best advice I can give.
I have never uploaded anything to a forum or youtube so I didn't even consider the server space. The error said the format was invalid and that was what I was asking about which most probably would have led us back to this. I guess I would have rather seen an error due to file size. That would have given me a better hint to what was wrong.
Take care and happy flying!
Ok...I think I figured youtube out at least enough to upload the video. I think the test is at this URL. No promises or refunds!
Some thoughts regarding vision sensors. They are not perfect. On page 20 of the Mavic 2 manual it shows the operating angles of the various sensors. The front is 70 degrees, tilted down 5 degrees. The bottom is 100 degrees. It seems as though there are dead spots depending on angle of attack. In addition there are speed limitations of the sensors, the fronts are limited to 14m/s (31mph). The bottom sensors do not have a speed spec. There is an overall sensor speed spec of 31 mph (50 kph) but it is a a height of 6.6 ft (2m). It’s possible that closer to the ground they are not fast enough to operate properly.
That does make a lot of sense. I didn't want to crash my M2P and while the angle of attack was pretty much the same, the timing of letting off the vertical down stick and the height was in no way the same each time. Most of the time I was looking to let off at around 5 to 6 feet and going maybe 20 to 25 mph. Possibly, if I didn't let off in time the front sensors did kick in at least most of the time and save me. I do know that when I could pull it off correctly, normally I could keep going horizontally along the ground but didn't even try that many times. The only crash I had was when the sensors were turned off and that was after the drone had finished its vertical decent and was going completely horizontal. So in the end, the sensors may have saved me more than 30% of the time even though I do agree there are dead spots so to speak.
Take care and happy flying!
I think it’s been fairly well covered that your sensors won’t keep you out of trouble when flying over water.
One other point worth noting is that when you’re descending over water through your display there’s no point of reference to give you a visual cue how far off the water you are - since it’s more or less uniform in many instances (and usually flying with a fairly small display) being at 10m looks roughly similar to being at 0.5m. For this reason, flying VLOS is essential.
One other trick I’ve learnt is to do your start up prodcedures right by the water’s edge. Being what it is, water tends to sit at the lowest point, so if start a few metres higher, you 0 altitude reference height will be at that height. This technique will allow you to fly closer to the deck using instrument flying, but of course this is not without risk,
BUT, the shot you’ve described is pretty high risk, so I’d approach it with caution.
Whenever I do high risk or tricky compound shots (when there are obstacles around or when I want to conetrate on operating the camera) I use a Litchy mission. I build the mission and then set all the parameters up to do it very slowly and with the camera pointing in the direction of travel. Run it through a few times and make any adjustments needed. Once I’m absolutely comfortable that it’s going to safely fly the mission, I then start to bring the speeds up within the mission until I have the shot I’m after. The trick to this approach is patience, and I can easily burn three batteries getting a relatively short compound shot.
One other point worth noting is that when you’re descending over water through your display there’s no point of reference to give you a visual cue how far off the water you are - since it’s more or less uniform in many instances (and usually flying with a fairly small display) being at 10m looks roughly similar to being at 0.5m. For this reason, flying VLOS is essential.
One other trick I’ve learnt is to do your start up prodcedures right by the water’s edge. Being what it is, water tends to sit at the lowest point, so if start a few metres higher, you 0 altitude reference height will be at that height. This technique will allow you to fly closer to the deck using instrument flying, but of course this is not without risk,
BUT, the shot you’ve described is pretty high risk, so I’d approach it with caution.
Whenever I do high risk or tricky compound shots (when there are obstacles around or when I want to conetrate on operating the camera) I use a Litchy mission. I build the mission and then set all the parameters up to do it very slowly and with the camera pointing in the direction of travel. Run it through a few times and make any adjustments needed. Once I’m absolutely comfortable that it’s going to safely fly the mission, I then start to bring the speeds up within the mission until I have the shot I’m after. The trick to this approach is patience, and I can easily burn three batteries getting a relatively short compound shot.
All of this will definitely be vlos. Just the latency of seeing it on screen will cause me to crash. I will not be operating anything but the sticks! I will take a look at Litchy to see if it might help. I'm just trying to learn to fly and learn what the capabilities are. Since I don't know anything about Litchy, will it control a full dive at 10 to 20 mph or does it not do that type of flight. Thanks a bunch!
Take care and happy flying!
Move slow. Record at the correct settings. Adjust speed in post processing. Simples
Yea, knewt suggested flying the mission backwards, flying low and then assending, and then reversing it post. Right now I know nothing about post. The video I put up is just cut up to give everyone an idea of what happened. Lots to learn before I try it. Your suggestion is another I will consider. Thanks for the idea!
Take care and happy flying!
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