INVESTIGATORS BUYING CIVILIANS' CAMERAS.

Byline: Charles F. Bostwick Staff Writer

Investigators are purchasing dozens of cameras and video cameras from people who shot images of space shuttle Columbia's destructive re-entry, intending to analyze them as part of the disaster investigation.

Among the cameras being purchased are those used by Daily News freelance photographer Gene Blevins, who captured images of bright flashes in Columbia's trail as it passed over eastern California. He also has turned copies of his photos over to the National Aeronautics and Space Administration.

``The intent is for the engineers and teams to get these cameras and dissect them and analyze them and compare them against the film we already have,'' said NASA Johnson Space Center camera team leader Greg Della Longa.

Acquiring the cameras is part of the investigation board's strategy of bringing together many data sources as it tries to determine what happened to Columbia and pinpoint the location of debris that separated from the shuttle early in its descent.

Besides analyzing video footage turned in from amateur astronomers and space flight enthusiasts, investigators are looking at defense radar records, telescope images and infrasonic data from the National Oceanic and Atmospheric Administration.

The space agency also is using its own version of the high-altitude U-2 spy plane to scan for traces of wreckage from the spacecraft.

In analyzing the videos and photographs, experts look for planets and stars to determine exactly what time and in what direction the images were taken from. They calculate the probable path of falling debris by estimating its weight, density and other features, then incorporate atmospheric and wind data. Then they look on radar records for signs of the debris.

The process serves to drastically reduce the area that must be searched, officials say.

Blevins said he was told by a NASA official that the images shot by him and fellow photographer William G. Hartenstein, a regular Aviation Week trade magazine contributor, are the only ones from that section of the shuttle's descent, as the spacecraft was already beginning to break apart.

Blevins and Hartenstein photographed the pre-dawn re-entry from Caltech's Owens Valley Radio Observatory, near Bishop.

Video shot seconds later by an amateur astronomer near Reno and radar records led to a search for debris in the Nevada desert north of Las Vegas.