Assessment of WakeMod 4: A New Standalone Wake Vortex Algorithm for Estimating Circulation Strength and Position (Invited)

WakeMod 4.1 (WM41) is a new standalone algorithm for estimating circulation strength and position of aircraft wake vortices from the Lockheed Martin WindTracer ® spectral data product. Preliminary results of a comparison of WM41 and the Lockheed Martin Offline Wake Processing (Legacy) wake algorithm are presented. Evaluation of the WM41 algorithm was accomplished using both simulated data and field observations obtained at four different airports. There are three principal findings of this study. The first finding is that WM41 provides similar performance to Legacy for Heavy aircraft in the ability to estimate circulation strength. An additional benefit of WM41 circulation estimates is that they do not show high sensitivity to SNR, which is a known limitation of the Legacy wake algorithm. The second key finding is that WM41 and Legacy provide similar estimates with regard to vortex position for Heavy and Large aircraft. Previous studies have indicated that the Legacy algorithm estimates vortex position to within 10 meters, and indications of this preliminary study is that the WM41 algorithm estimates are as good or better in that WM41 provides more consistent estimates of vortex pair orientation and spacing throughout a wake track. Furthermore, WM41 position estimates are not affected by the choice of a region of interest. The third principal finding of this study is that WM41 can detect and estimate circulation strength of weak vortices below the sensitivity limit of the Legacy algorithm (approximately 125 m 2 /s), and thereby allows for improved estimation of aircraft wake behavior for aircraft smaller than Heavy, and in the estimation of vortex strength at late wake ages when vortices are weak.