Determine the horizontal distance between two points A and B whose elevations above datum are hA$=993$ft hA$=993$ft and hB$=1099$ft hB$=1099$ft and whose images aa and bb on a vertical photograph have photo coordinates xa$=108\mathrm{.}81$mm xa$=108\mathrm{.}81$mm$,$ ya$=73\mathrm{.}73$mm ya$=73\mathrm{.}73$mm$,$ xb$=87\mathrm{.}05$mm xb$=87\mathrm{.}05$mm$,$ and yb$=52\mathrm{.}14$mmyb$=52\mathrm{.}14$mm$.$ The camera focal length was $3-1/2$ in$.$ and the flying height above datum $4070$ ft$.$ Express your answer in feet to $4$ significant figures.