Similar to Problem 27.12, except that the camera focal length was 3-1/2 in., the flying height above datum 4075 ft, and elevations hA and hb 983 ft and 1079 ft, respectively. Photo coordinates of images a and b were xa = 108.81 mm., ya = −73.73 mm., xb = −87.05 mm., and yb = 52.14 mm.