1. Reflectance and Sensor Basics

2. Light and Plant Relationships

3. Plant Tissue and Reflectance

4. Plant Tissue and Reflectance
VISIBLE
NEAR-INFRARED
Reflectance
Controlled by
Leaf Pigments
Cell Structure
Bare Soil

5. Active Sensor Basics

6. Sensor Field of View (FOV)

7. Data-Plant Relationship
GreenSeeker
NDVI is measurement of how “green” and how much plant material. Note how size of plant takes up larger percentage of the field of view of the GreenSeeker. Even the same “green-ness” will have effect on NDVI value. Could also be combinations of size and “green-ness”.

8. Amount of Plant In Field of View
0.40
0.50
0.60
0.70

9. Vigor of Plant In Field of View
0.40
0.50
0.60
0.70

10. Data-Plant Relationship
GreenSeeker
Similar effect with broad acre crop like wheat. Higher plant density/less soil in the FOV of the sensor affects NDVI value.

11. Hand Held Data Collection Exercise