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Table of Contents
1. Introduction
2. Sensors
3. Microwaves
4. Image Analysis
5. Applications

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Fundamentals of Remote Sensing

Chapter 5
 

5.5.2 Did You Know?

Another part of the electromagnetic spectrum that has been used for soil moisture measurement is the gamma ray wavelength range. Recording the natural emission of gamma rays from the earth, aircraft carrying gamma ray spectrometers are used to detect the attenuation or alteration by soil moisture, of the intensity of the emanation. The gamma ray wavelength is extremely short - about 10-12 metres in length (!) and the intensity of this natural radiation at the earth's surface is very weak. As a result satellite altitudes are not practical for this form of remote sensing. Even the aircraft used for this purpose must fly as close to the ground as possible.

Section 5.5.2 Section 5.6
Updated2002-08-21 go to top of page Important Notices