Coral Reef Mapping / Stitching Issues, etc

We’re in Jamaica & trying to map the progress of growing coral reefs from year to year.
I know I’ve been warned about the stitching software not dealing well with water but this is very clear & still & shallow water.
Note that almost this entire image is underwater/completely submerged except for the far tight side where the trees are.
I’m attaching a clip of our first attempt.
I’m actually quite happy with it even though we had some issues.
I’m hoping to get some answers here.


This day was very clear but the water was a bit rougher than we hoped for. Still very happy with what we achieved.

There were focus & exposure issues on the first battery flying North to South along the beach on the right side of the image. That was resolved for the most part after the battery change.
I will try in full manual exposure & focus on the next test.
Any suggestions?

There are some very strange “Sawtooth Stitching Patterns” on the right side, that appear to be in-between the first leg/battery & second leg/battery.
This will be a problem if we can’t resolve this issue.
Any ideas why this happened?
Is it possible it has to do with the out of focus fist leg confusing the stitching software with the focused second leg?

Lastly, The map lines up very well with the GPS Google map on my iPhone, which we flew the mission with, but it is way off the marks when I view it on my Macbook pro.
Any idea why there this is happening?

Any & all constructive help is appreciated.
Thanks in advance.

Did you takeoff from the same spot for the 2 parts? If so, do you have a photo of the start spot while the drone is on the ground? If so are the recorded GPSAltitude the same? To see GPSAltitude right-click on picture, select Properties > Details and scroll down to GPSAltitude. If the altitudes are not the same, perhaps this contributed to the stitching problem, causing a saw-tooth pattern as it bridged from one elevation to the next.

Hi @jmitteco,

I highly encourage you to use full manual exposure and focus settings on your next flight to see if these issues persist. In regards to the other issues with your map, can you share the name of the map(s) as well as the e-mail address associated with your DroneDeploy account? You can send these over to me in a private message.


The sawtooth could be due to the blurred images in area one, but they could also be due to the homogeneous water compared to the left area that has more details to stitch with.

You might try something like this. Sometimes I will fly at two altitudes and upload both sets as one map. The higher one supports better alignment and stitching and the lower one supports better resolution. I did this with a P3P (similar cam to the Mavic) at 150 and 300 feet. I uploaded each separately and both together to test variations in resolution. The 150 foot gave .8 in/px resolution and the 300 foot gave 1.5 in/px. Both together gave .9 in/px. If the lower one works, I use it. If not, I lose very little with the combined set. The altitudes may need to be adjusted depending on subject matter.

Yes, I did takeoff from the same spot on all 3 batteries.
I did not do a photo from the drone while it was on the ground.
I’m convinced the sawtooth pattern is due to the out of focus first leg.
Will be going full manual settings & focus on my next attempt.

I’m convinced the sawtooth pattern is due to the out of focus first leg.
Will be going full manual settings & focus on my next attempt.
I’ve done some more manual testing over land & looks pretty good.

I’m convinced the sawtooth pattern is due to the out of focus first leg.
Will be going full manual settings & focus on my next attempt.
Quite happy with the results of the last two legs where everything is in focus & has decent exposure.
Thanks for the input.

On my Phantom 4 Pro when DroneDeploy flies a mission it usually takes a picture at the takeoff location automatically. Have you looked at all your pictures? Is there one taken on the ground? Perhaps the Mavic Pro does things differently.

Not sure where you want me to “right-click” on the image to get altitude?
I’m on a Mac & it doesn’t show “properties”.
If I Command>i I get latitude & longitude. Not seeing altitude.

I’m on a PC so I not sure what to do on a Mac. When I say right-click, I mean in the file browser where you can see all the files listed in a directory. How do you look at the properties of a file on a Mac? That is what I am doing on the PC. It lets me see much of the information in the Exif data of a picture.

Another way to get the altitude data, at least for the P4P, is to open the file in a simple text editor like Notebook and then scroll down to find the entry that says AbsoluteAltitude.

Any luck finding the altitude information? Be aware that the altitude shown in DroneDeploy when you look at an individual picture is the altitude above the takeoff point not the absolute altitude.