Import Landsat 7 & 8 thermal images - Dragonfly

grasshopper dragonfly-legacy
1

Hi all,

Has someone managed to import Landsat 7 & 8 thermal images through Dragonfly?
I´ve got Landsat 4-5 working pretty well, but when I try with more recent versions it produces unexpected results. I guess there are some small modifications to the band/file naming and metadata structure.

I´ve seen it on the list for Dragonfly+ (which looks very promising!), but perhaps someone has a workaround in the meantime.

Rafael

2

@RafaelA ,

I am sorry to say that I have not yet added support for LANDSAT 7 and 8 images in the Dragonfly plugin or core libraries yet. As soon as I finish cleaning up the UWG API in Dragonfly+ (which should be pretty soon), I think the next priority will be to build objects for LANDSAT images and I will do it correctly this time (the LANDSAT 5 support in Dragonfly Legacy plugin is very hacky).

The best workaround that I can give you for now is that I think the conversion formulas for going from digital numbers for the thermal TIFF image to temperature in Celcius are pretty similar to those used in LANDSAT 7+8:

So, if you grab the right thermal image TIFF from a LANDSAT 7 image, I think you can use the same formulas to get temperature.

3

Thanks for the update Chris!
The formulas are very useful, I´ll try to play around with them and see if I manage to make it work in the meantime.
Rafa

4

Hi @RafaelA and @chris, Has there been any updates to the LANDSAT image processing workflow since this last discussion?

1 Like
5

Hi @chris, just reviving this topic here to know if there is any roadmap regarding reading surface temperatures from Landsat 7 8 9?

best,
Olivier

6

Hey @OlivierDambron ,

It’s still pretty far from our highest priority and, if you really want this capability, I might recommend using some type of Remote Sensing Software to process the LANDSAT images that you download instead of waiting for me to release something. 10 years ago, I used to use the ENVI software (listed on that Wikipedia page) to process the digital numbers in the raw image data into temperatures. I don’t know if it’s still the state of the art but I know packages like ENVI are much more devoted to this type of thing than Dragonfly was/will be.

1 Like
7

Thanks Chris,
Google Earth Engine is a great resource for importing, viewing, and analyzing remote satellite data as well . NASA created a few useful tutorials describing the basics: ARSET - Using Google Earth Engine for Land Monitoring Applications | NASA Applied Sciences