Welch parabolic window 1 - 4 x^2 on [-1/2 1/2]
WelchWindow[x]
WelchWindow[x, α]
Plot[WelchWindow[x], {x, -1, 1}]
→ -Graphics-Plot3D[WelchWindow[x]WelchWindow[y], {x, -1, 1}, {y, -1, 1}, PlotRange -> All, Exclusions -> None]
→ -Graphics3D-WelchWindow[0.1]
→ 0.96