An Imaging Vegetation Status Monitoring System Mini Senior Design Project Submitted by Hector Erives August 31, 2005

Objectives: Use of a small computer-camera with color filters arrangement to take images of vegetation. Development of a system that will be unattended for weeks. The system could be powered by a battery or PV cells. The product will be ratio images (2D maps) of a field, of the NIR to Red bands.

Tools and Methods: A monochrome CCD camera with Red and IR filters (or a wheel filter). Standard CCD cameras: 1024x1024 pixels, 12-bit resolution (4096 DNs). Standard CCD camera lenses. Red filter (650 nm CW), NIR filter (850 nm CW). A PC, Laptop, or a Single Board Computer (SBC) with enough memory to save the images, i.e. Image=(1024x1024 pixels)x12 bits/pixel/8 bits/Byte=1.5 MB. Required: 2 images (Red,NIR) of the scene x 3 images/day. Could save only the Ratio to save memory. i.e. Ratio=NIR/Red

Tools and Methods: Use MATLAB to manipulate the images, i.e. compute the ratio in a pixel-by-pixel basis, i.e. The product will be ratio images of 1024x1024 pixels. Can also write a program in “C”, Visual Fortran, or IDL to manipulate the images. Save the ratio images to a file with a name so that it differentiates from the rest of the images (from other times and dates), i.e. ratio_9:40_9105, ratio_1:30_9105, … Could use a standard Nickel-Cadmium battery (economic solution) mA – 4A. Can also use Photo-Voltaic (PV) cells but have low efficiency (< 15%).

Why use Red and NIR wavelengths?: DNs or Reflectivity Wavelengths (nm) UV(400nm) Red (650nm) NIR(850 nm) Healthy vegetation Vegetation with lack of Nutrients (water, fertilizer) Soil Low DNs (Reflectivity 0) High DNs (Reflectivity 1)