Measurement of the deviation of a laser beam from a straight line, where the laser beam is of a type which causes thermal blooming, is used to determine the integrated effect which wind will have on an article traveling through airspace, for example, to enable an adjustment in the aim point of the article. The invention includes correcting the aim point of a gun firing a projectile, correcting the flight path of an aircraft, and correcting the path of a watercraft. The invention includes a method and means for measuring the flow of fluid in a conduit or as a free mass, for purposes other than adjusting the path of a projectile or the like.