After the required distance had been traveled, subsequent non-overlapping images

were grabbed along with position information from the DGPS receiver. Immediately the

encoder counter value was reset to zero so that the relative distance from the new

imaging position could be used as reference for the next image. The algorithm continued

until the user terminated it. Imaging sequence in the field trial is shown in Figure 3-7.

Images were taken over two days in the Hield. The height of the camera was adjusted only

once at the beginning of the day and remained at the same position throughout the day.

The camera Hield of view was calculated on both imaging days and the encoder was

programmed to reflect the current Hield of view settings. The experimental setup and

encoder are shown in Figures 3-2 and 3-4.

 3.7 Prediction of number of fruits/plot

 In the grove where the citrus yield mapping system was tested, two trees in each

plot were designated for hand-harvesting. Fruit/plot were predicted based on three models

using the following three variables:

 1) Number of fruit estimated using fruit counting algorithm ( rNsft)

 2) Number of citrus pixels/plot estimated using fruit counting algorithm (NP,,xezs)

 3) Number of fruits/plot estimated using citrus pixels/plot data ( ~ruits-plxels)

Images belonging to a same plot were grouped together and the number of fruits

estimated by the fruit counting algorithm was summed up to give the number of fruit/plot

estimates, using the following variables: mt,,ts, Nplxels, and N~ruits-plxels-

 rmes,, used the number of fruits identified in an image by the machine vision

algorithm while NP,,xez used the number of citrus pixels in an image. N~ruits-plxels USed a

relation between the actual size of the fruit and the size of the fruit in terms of pixels in

an image. Relation between a pixel size and its corresponding actual size in the imaging