grid

Taken from Glacier Point ( 37.73083, -119.57278 ) at 09:44:29 PDT (16:44:29 UTC) with an iPhone 4. Center of image is azimuth 080°.

I've revived the contrail pattern simulator on ContrailScience so the controls work again, and made it so it can be embedded in a post here. . Note this is actually two different contrail simulators - the default shows two intersecting flight paths creating a grid, the other shows a racetrack...