use of waas can reduce position error to within
Wide Area Augmentation System The WAAS specification requires it to provide a position accuracy of 7.6 metres (25 ft) or less (for both lateral and vertical measurements), at least 95% of the time.[2] Actual performance measurements of the system at specific locations have shown it typically provides better than 1.0 metre (3 ft 3 in) laterally and 1.5 metres (4 ft 11 in) vertically throughout most of the contiguous United States and large parts of Canada and Alaska.[3] With these results, WAAS is capable of achieving the required Category I precision approach accuracy of 16 metres (52 ft) laterally and 4.0 metres (13.1 ft) vertically.[4]