DSM and Sea Level

Hello Jeremy,

THANK YOU FOR YOUR REPLY. If you could change check out Wampler (6) and Wampler (5) that will give you and idea of how far off these elevations are. Keep in mind that these are flat cornfields right next to each other. There aren’t any major dips or sinkholes as I’ve walked the majority of this area.
Thank you

If you exclude some of the blue in the edges of those two maps, it seems like the elevation data is saying it’s a pretty flat map. As for the difference between the two I think that could be due to some GPS inaccuracy on the Phantom/Inspire. The starting altitude is only going to be good within a few meters. I might be wrong about this and @jeremy can probably add more.

Well yeah, they are pretty flat, but farmers don’t want pretty close. A few, 3, meters equals 9 feet. Thats a major difference. Let’s say 1 meter, that’s still 3 feet and that is enough to cause puddling and growth issues within a field of corn. Within a flood plain it could be even worse.
What is the answer to this problem? If a few meters is satisfactory in your eyes, then it’s a shame but we would not be able to use this promising service.

I am referring to the few meters difference between the two maps, which is just a difference in what it thought its starting elevation was. If it makes it easier to read we could start the legend at zero. This would make it read as both of those maps are around 1-2 meters high.

That would actually be better. It would give a clearer definition of the elevation rather than a guessing game.

@jeremy can probably explain more than I can. We’d have to provide an option or a way to do that. From what he was telling me there are a lot of cases where people want those actual values.

I see your issue - the scales can definitely be confusing the way they are at the moment (especially if the two fields show different global values). As mentioned before, we are adding in some finer control over elevation values so that you can show relative changes rather than global elevations, but that will be a couple of weeks.

We are also working on improving the accuracy of the height variations across each map. We are certainly not satisfied with merely satisfactory results and constantly working on improving all aspects of map quality, so if there is a map where you’re seeing more height variation reported on the DSM (i.e. the difference between the min and max values on the colourbar) than there actually is when you inspect the field, then we can have another look at the data to see if we can improve the results for you. If you point me at a particular map where you saw unrealistic variations then I can investigate further. This kind of feedback is really useful to us as we improve our software, so please do keep it coming!

As @chasemgray mentioned, the reason we have the elevations shown as they are now is that some customers do want to see the global (or above sea level) values (e.g. for generating a contour map of a hillside). To accommodate all our users, we’re building the option to switch between global and local elevation differences to suit your specific needs.

In the meantime, I’d suggest just looking at the relative differences in elevations for your maps (basically just look at the difference between the max and min values on the colourbar on the left hand side of the data page to get an idea of the scale, and then just look at the colour differences across the map to see local height variations). Less than ideal, but we’re working on improving it so stay tuned…

The seasonal increase in water level of the seas and oceans

Would you enable the DTM and contour permissions for my account too? My email / login for the DD app os caiopc@ipt.br . Thanks!

Hi Jeremy,

I have the same issue with vegetation/trees affecting my elevations. Could you please enable DTM and contour permissions for your account? I would like to rerun elevations on my processing site and camp maps.

Thank you


Hi @mrowbottam,

I had my teammate @Stephanie take a look at your account and it appears that you already have Contour permissions enabled for your account. Can you share some specific details about your issue so we can take another look?