[R-sig-Geo] Antw: problem with ndvi

2012-01-24 Thread Matteo Mattiuzzi
Dear Vikram, I have update the RemoteSensing package in order to easily compute the DN to reflectance conversion. For Unix system you should be able to update RemoteSensing to 0.4.2 with this updates. On Windows you have to wait a little more. try: metafile -

Re: [R-sig-Geo] Antw: problem with ndvi

2012-01-24 Thread Vikram Ranga
Dear Matteo, I work on windows, but I calculated the NDVI from on sensor reflectance (toa reflectance) with 'Landsat' package. I already try the 'RemoteSensing' package and really liked it. Though I am waiting for windows version of this package. I found this bit easier than 'landsat' package.

Re: [R-sig-Geo] Antw: problem with ndvi

2012-01-19 Thread Agustin Lobo
Matteo, by RemoteSensing package you mean the landsat package? Agus 2012/1/18 Matteo Mattiuzzi matteo.mattiu...@boku.ac.at: Dear Vikram, It is not good to calculate NDVI from DN. The purpose of DN (digital number) is only for packing as much information as possible into a given “BIT-size”

Re: [R-sig-Geo] Antw: problem with ndvi

2012-01-19 Thread Matteo Mattiuzzi
Hi Agus, no I mean the RemoteSensing package https://r-forge.r-project.org/projects/remotesensing/ Cheers Agustin Lobo alobolis...@gmail.com 19.01.2012 11:26 Matteo, by RemoteSensing package you mean the landsat package? Agus 2012/1/18 Matteo Mattiuzzi matteo.mattiu...@boku.ac.at: Dear

[R-sig-Geo] Antw: problem with ndvi

2012-01-18 Thread Matteo Mattiuzzi
Dear Vikram, It is not good to calculate NDVI from DN. The purpose of DN (digital number) is only for packing as much information as possible into a given “BIT-size” (in Landsat 8-bit/pixel/band). DN is practically the radiance (I think TOA?) modified with an offset and a gain in order to