Now lets extend the last exercise by programming the drone to fly a search grid. When flying a grid, we move forward some distance, turn 90 degrees, move laterally a short distance, turn 90 again, then fly back the same distance. Then we turn the opposite way 90 degrees, fly forward a short distance, then turn another 90 the same way, then repeat the movements. This results in flying a pattern that covers a rectangular area. Search grids are used to examine an area looking for some target or perhaps for mapping the area.