Friday, February 13, 2009

The Wiki Power

Last week I could experiment the power of cooperative work on the Internet.

In the frame of the development of the ORFEO Toolbox (OTB), I was doing some bibliographic research. I wanted to find as many radiometric indices as possible that I could compute using optical multispectral remote sensing data. My problem was mainly focussed on Pleiades-like data, but I thought that it would be interesting to widen the search. After all, these indices are going to be coded in OTB, which has a rather heterogeneous user base.

Unfortunately, I have no easy access to application oriented remote sensing journals, so I was facing a tedious work.

I started with the most well known indices as NDVI and I wrote some descriptions for them in the OTB Wiki. As I was on the wiki, I thought I could ask some other people to complete the documentation, so I sent an e-mail to several mailing lists where I knew that people knew about radiometry issues.

To be honest, at the beginning I thought that it would be useless. I had a good surprise, when the next morning I saw that somebody had created a new account on the wiki and was formatting and enriching (adding some descriptions and bibliographic references) to the list of indices I had started. The day after that 2 other people joined the effort and added new indices and useful information.

The list is accessible here. At the moment of this writing, the list seems to be stable and contains 14 vegetation indices, 8 water indices, 3 soil indices and 2 built-up indices. Most of them where immediately coded in OTB.

This is a real win-win approach: you give us the formulas, we give you the code.