3.7 Experimental Procedure

A schematic diagram of the overall experiment setup is shown in Figure 3-6. A DGPS

receiver and camera control interface were connected to the computer through the serial

ports available in the computer. A video signal from the camera was fed into the imaging

board and data from the encoder was fed into the counter input channel of the PCMCIA

I/O board.

 C amera




 Serial Imaging
 Port #1 Board

 Computer
 Serial PCMCIA
 SPort #2 Board vo



 DGPS 12V Power Encoder
 Receiver Supply


 Figure 3-6. Schematic diagram of the overall citrus yield mapping system.


Once the camera was mounted on the top of the pole, the camera field of view was

measured and the width and height of the imaging scene were calculated. Based on the

width of the image scene, the encoder was programmed to prompt the user when the

required distance has been traveled from the current imaging location to take subsequent

non-overlapping image. After aligning the first image with the tree, the truck was driven

very slowly (2.2 m/s) and the pulses from the encoder were read continuously with a 20

ms time interval to measure the distance traveled from the previous imaging location.