[GRASS-user] Derivation of Landsat 8 Tasseled Cap coefficients for certain scene in Grass

[Moritz Lennert]

On 09/06/15 23:42, Kozlova Maria wrote:
> Dear all,
> Asking for help in sudden difficult situation:
> I need to derive proper,  'personal', Tasseled Cap coefficients for some scenes of my study area.
> I know, such procedure can be done by Matlab, but unfortunately, my colleague who could do this have now some troubles and cannot help me at the moment.
>
> I need to do this work but can use only Grass. So is it possible to derive my own TC coefficients for each scene using Grass? If so, which modules should I use?
> Is it possible to do image Tasseled cap transformation with these new coeficients?
> Am I right, that Grass module i.tasscap only provide TCT with use of standard TC coefficients (in the case of OLI images derived by M.H.A Baig et al, 2014)?

Yes. BTW, the module is actually "just" a python script [1], so you 
easily modify the coefficients if you want to.

Tassled cap coefficients are derived via principal component analysis + 
possibly some rotation. You can actually get pretty close by just doing 
your own PCA using i.pca. As Nikos said: it all depends on what you want 
to do.

Moritz



[1] 
https://trac.osgeo.org/grass/browser/grass/trunk/scripts/i.tasscap/i.tasscap.py