Shuozhang insights
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Boonsong Lake
As X=0, Y=0 refers to the pixel in the upper-left corner of the image, the Y-coordinate should be reversed. The B1 penetrates water and B5 absolutely absorbed by the water, the area that shows a large number of B1 and B5 is more likely to be the water body. The chart of B1 and B5 shows that the Boonsong Lake is roughly in the upper middle of the image. The length of the lake approximately covers from upper left of the lake: X=328, Y=95 to bottom right of the lake: X=418, Y=160. Then the length of the pixel is around 111 which means 96.8 is corresponding to 3000 feet in the real situation which means 1 pixel-length is 27 feet. The lake’s area on the map is similar to a rectangle minus a triangle. The four vertices of the rectangle are bottom right: X=418, Y=160; bottom left: X=397, Y=179; upper right: X=354, Y=67; upper left: X=328, Y=95; the lengths are 28.3*27=764.1 feet, 112.9*27=3048.3 feet, 107.2*27=2894.4 feet, 40*27=1080 feet, then take an average would be 922 feet and 2971 feet so the area is 922*2971=2739262 which is around 2.74 million square feet. The three vertices of the triangle are X=397, Y=179; X=383, Y=165; X=408, Y=163; the lengths are 19.8*27=534.6 feet, 19.4*27=523.8 feet, and the area is 534.6*523.8=280023.5 which is around 0.28 million square feet. Therefore, the area of the Boonsong Lake is nearly 2.74-0.28=2.46 square feet.
