What's the best way to use remote sensing data to measure soil moisture?

Question

I want to find out how to use Landsat multi-spectral imagery to measure soil mosture on some absolute scale to determine one of many factors that may indicate irrigation activities on agricultural fields.

Answer 1

There are a few algorithms that you can use. You need to find the one that best suits you conditions and spectral values. Some GIS programs already have some algorithms for this purpose, but i don't know where you would get other algorithms from though other than the ones already in the GIS program.
I did something like that in university a few years ago and got a good image as a result, however, buggered if I can remember what algorithm I use.
Sorry

Answer 2

Hmm, too bad you don't have access to Synthetic Aperature Radar data. Landsat data is more useful when combined with SAR data since radar can see through clouds which often cause areas of missing data in Landsat images. The combination is great, you get the higher resolution of the Landsat data combined with the in-fill of cloud covered areas by the radar data. If you have access to programs like ERmapper perhaps you could map the infrared range and post that as a gradient it might allow you to somewhat quantify the data. I'm not an ERmapper expert but I've seen people do similar things with algorithms in that tool. Quantification will be tricky though because of problems like cloud cover obscuring parts of your data.

Here are a few links to articles that discuss using remote sensing imagery for your purpose:

http://landsat.gsfc.nasa.gov/about/Application1.3.html

http://landsat.gsfc.nasa.gov/education/compositor/

http://chesapeake.towson.edu/data/all_landsat.asp

http://nsidc.org/data/docs/daac/nsidc0199_smex_landsat_tm_gd.html


Hope this helps a little. Good luck and have fun!

Answer 3

From a distance~thus "remote"~.