(meteorobs) Earth grazer ID from single station

Gural, Peter S. PETER.S.GURAL at saic.com
Thu Sep 25 20:17:31 EDT 2008


YCSentinal;
 
It may be possible to identify a grazer from a single station video record by examining the change in apparent angular velocity across the entire trajectory. You would need angle rate from each frame and a well calibrated field of view that accounts for wide field distortions (3rd order or barrel for fisheye lenses). There is a closed form expression of the apparent angular velocity as seen from the camera that changes with radiant distance, entry velocity, and range. It likely has an inflexion point at CPA and thus could be used to id a grazer. I will have to work on this to see if there is any characteristic to the changing values that could be used to advantage. One normally only considers meteors dropping from higher to lower heights so this has been largely ignored from the perspective of numerical solution. For long length/duration meteors, it is actually possible to solve for the radiant position from the changing angular velocity observed. One issue however may be that very wide field cameras won't have sufficient angular resolution to discriminate changes in the angular velocity.
 
Pete Gural



More information about the Meteorobs mailing list