Greg, that gives you airspeed, not ground speed as they can be very different, depending on the direction the plane is flying when compared to the wind. With a 20MPH wind and an IAS of 90MPH, your ground speed could be as low as 70 or as high as 110. This is why it's preferred to land into the wind, it lowers the ground speed. It's also why an aircraft carrier turns into the wind during flight ops. The ground speed is lowered by the headwind AND the ships speed lowers the ground speed further at the point of touchdown, reducing stress to the arrestor gear on the ship and the aircraft landing on it