I have some AVIRIS hyperspectral imagery which covers a small area. I would like to scale this up using Landsat to cover a larger region. Is there a way I can find the Landsat equivalent bands in my data. For instance, the NIR peak in vegetation occurs in band 5 of Landsat 8 OLI imagery. How can I link this with my AVIRIS data? I essentially want to reduce my AVIRIS data (currently over 430 bands) down to the 7 most important bands that match Landsat (C,B,G,R,NIR,SWIR,SWIR2).
Hi Nathan,
You are right. If you need to compare the two images, you have to do a little manipulation on the AVIRIS data.
As you pointed out, you can reduce the AVIRIS data down to the 7 most important Landsat bands. One way to do this is to use the center wavelength of the landsat bands and pick the 7 channels of the AVIRIS that match the bands. For example: channel 24 (665nm) of Aviris = landsat band 3; channel 137 (1653nm) of Aviris = landsat band 5; and so on...These are just sample numbers, and in your case, you have to check your AVIRIS 430 bands to find the matching channels for the Landsat. This is the easy way.
Another method is to do the weighted average of TM corresponding channels. In this case, you are simulating the landsat bands for the AVIRIS data.
Please check the PDF below for more. I hope this helps.
http://aviris.jpl.nasa.gov/proceedings/workshops/02_docs/2002_Lee_web.pdf
Hi Nathan, in ENVI you can use spectral resampling according to filter functions (.sli files). It is really straightforward but you might want to consider the other options given as well. Hope that helps as well. Best wishes, Richard.
You can also consider to choose all AVIRIS bands that fall into the range of corresponding Landsat 8 bands and perform Principal Component Analysis (PCA) on them. PCA decorrelates cell values to get the highest variety of informations, which is one of best methods for reducing redundant channels.
An input number of components is equal to number of original bands, and in result you should choose the first component.
I agree with Richard, 'Spectral Resampling' in ENVI is one of the ways to do it. I have tried with hyperspectral laboratory measured reflectance values from 1.2µm to 16 µm and resampled it to e.g., ASTER TIR bands using Spectral Resampling tool and it works just fine. In fact with ENVI version 5.2 you will find pre defined L8 OLI filter function.
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