Quoting: Anonymous Coward 27963234
could we work some assumptions depending on the make, angle & height of the craft at the time?
obviously certain planes simply have no windows pointing the to ground unless the plane is landing or banking right?
Wouldnt really matter, its entirely possible and have read of people doing this.
The initial beam is tiny, averaging 2-3mm collimated to parallel. To get the angle would simply require the operator of said laser to be holding it at the top of a small window aiming down, keeping it as close the bottom edge of the frame as possible.
As the beam covers distance and diverges, it becomes quite large. The ground viewer would not see a small dot, rather a large area being covered.
To assume anything related to the plane other than height would pointless.
Saying they were 'scanning', as in rendering an image, is unlikely. Either the OP is exaggerating, or the person who saw it was.
Military uses IR systems, not visible wavelengths for one. Camera systems, guidance, all infrared. Even the small survey systems they use to scan a crime scene or construction site are IR. Using visible wavelengths means that they cant filter out the noise given off by street lights, cars, houses, and during a day operation, DAYLIGHT..
For further assumption, lets refer to Occam's razor