[GRASS-user] How to perform Layer reduction for hyperspectral image cube?

GRASS GRASS user
1

Dear All:

I want to reduce layers from NOVASOL hyperspectral image cube which has 140 bands/layers.

  1. How can I perform layer reduction
  2. If I want use i.atcorr should I process only a single layer at a time?
  3. if 2) is not how do I process all the layers in one go (the txt?
  4. Is there any means to include a new sensor outside what is lited in the ‘‘predefined sensor’’ e.g., 64: 4th band of ETM+ Landsat 7

Any assistance is appreciated.

Cheers,

–
Asefa Teferi Areda
MSc student Centre for Geo information and Remote Sensing

Wageningen University
Bornsesteeg1 3c 5
6708GA Wageningen
The Netherlands
E-mail: moybonat2u@gmail.com
Mobile: +31644565064

2

Asefa Areda wrote:

Dear All:

Hello Asefa,

I want to reduce layers from NOVASOL hyperspectral image cube which has 140
bands/layers.

1) How can I perform layer reduction

I have no experience with Hyperspectral imagery. But PCA should be a valuable
option to consider. Have a look at the manual

<http://grass.osgeo.org/grass64/manuals/i.pca.html&gt;

and some examples in a GRASS-Wiki page

<http://grasswiki.osgeo.org/wiki/Principal_Components_Analysis#Using_i.pca&gt;

2) If I want use* i.atcorr *should I process only a single layer at a time?

You "can" only process one layer per run.

3) if 2) is not how do I process all the layers in one go (the txt? 4) Is
there any means to include a new sensor outside what is lited in the
''predefined sensor'' e.g., 64: 4th band of ETM+ Landsat 7

a) You need to script it in order to get it run for multiple "layers" in one
go. If you work under Linux, I can send you a Bash shell linux script (off-
list) I have used to run i.atcorr for some Landsat scenes. It'll sure need
some hand-crafting as there are some hardcoded stuff.

Maybe some-one has already a "clean" solution on that.

b) For "adding new band filters", have a look at:
<http://trac.osgeo.org/grass/browser/grass/trunk/imagery/i.atcorr/README&gt;

Regards, Nikos