Friday, August 12, 2016

Scattering mechanisms for active sensors

Scattering mechanisms for active sensors

The three common scattering mechanisms for active sensors are:
  1. Smooth surface or specuar reflection: This kind of reflection comes from flat terrain like roads or water. In this type of reflection, very less energy of the transmitted radiation returns to the sensor. Pixels appear dark. Typical pixel values are less than -20dB.                                                                        
  2. Rough surface or diffuse scattering: This ype of scattering occurs on rough surfaces typically ploughed farms or vegetation. Radiation is scattered in all directions diffusely. Typical pixel values are greater than -20dB.                                                                                                                                     
  3. Double bounce backscatter: This type of scattering occurs when radiation bounces off a series of objects like vegetation and buildings. The reflected pulse hits one surface after another.Typical pixel values are greater than -10dB.