CEE 4221 Lecture Notes - Lecture 12: Spectral Signature, Diffuse Reflection, Specular Reflection

• School: Temple University
• Department: Civil Engineering
• Course: CEE 4221
• Professor: Brooks

Document Summary

Incident energy is completely reflected in one direction (cid:1) angle of reflection is equal to the angle of incidence. Reflection is maximum along the angle of reflectance. Reflection is negligible in other directions (cid:1) reflectance varies with sensor location and incidence angle (cid:1) occurs when the surface is smooth and flat (cid:1) wavelength > roughness (cid:1) specular reflection dominates (cid:1) (cid:16)(cid:13)(cid:11)(cid:11)(cid:5)(cid:17)(cid:3)(cid:9)(cid:14)(cid:8)(cid:9)(cid:18)(cid:7)(cid:19)(cid:20)(cid:3)(cid:8)(cid:12)(cid:13)(cid:7)(cid:15)(cid:9)(cid:10)(cid:3)(cid:11)(cid:6)(cid:3)(cid:4)(cid:12)(cid:13)(cid:14)(cid:15)(cid:1) (cid:1) Incident energy is reflected uniformly in all directions (cid:1) occurs when the surface is rough (cid:1) wavelength < roughness (cid:1) diffuse reflection (cid:1) Reflectance is same irrespective of the sensor location and incidence angle. Diffuse reflection contains the colour information of the surface (cid:1) (cid:1)(cid:2)(cid:3)(cid:4)(cid:5)(cid:6)(cid:7)(cid:8)(cid:9)(cid:7)(cid:15)(cid:21)(cid:9)(cid:16)(cid:13)(cid:11)(cid:11)(cid:5)(cid:17)(cid:3)(cid:9)(cid:10)(cid:3)(cid:11)(cid:6)(cid:3)(cid:4)(cid:12)(cid:13)(cid:14)(cid:15)(cid:1) Depends on the wavelength of the incident energy. Ideal specular reflector (cid:3) completely reflects the incident energy with angle of reflection equal to the angle incidence (cid:1) Ideal lambertian reflector (cid:3) scatters all the incident energy equally in all the directions (cid:1) (cid:22)(cid:23)(cid:2)(cid:3)(cid:9)(cid:14)(cid:11)(cid:9)(cid:10)(cid:3)(cid:11)(cid:6)(cid:3)(cid:4)(cid:12)(cid:14)(cid:8)(cid:17)(cid:24)(cid:1)