Byline: SARI HORWITZ AND CHRISTOPHER B. DALY Washington Post
WASHINGTON A Boston University scientist added to the controversy Thursday over the turnout at the Million Man March in Washington, saying his analysis shows the crowd was more than twice the 400,000 people estimated by the National Park Service.
A computer-aided study by Farouk El-Baz, director of the school's Center for Remote Sensing and an authority on aerial reconnaissance, concluded that 870,000 people attended the rally on Monday.
The center's study, requested by ABC News, involved computer image analysis of aerial photographs obtained from the Park Service. It has a margin of error of about 25 percent largely because of the poor quality of the color photographs which means the actual size of the crowd could have been as low as 650,000 or as high as 1.1 million, El-Baz said.
The center acknowledged that it had never made a crowd estimate before. It also discounted numbers provided by local transportation officials that suggest the gathering was closer to the Park Service estimate.
A U.S. Park Police spokesman said Thursday that the agency does not have the money for sophisticated computer analysis but that it stands by its estimate obtained by examining photographs made from video taken from a helicopter three times during the march.
Nation of Islam leader Louis Farrakhan, who said the march drew more than 1 million, said he will sue the Park Service to force it to revise its estimate of 400,000.
El-Baz, who is not affiliated with the Nation of Islam, established the center in 1985 to study surface and sub-surface features from a distance, using photography and radar.
ABC's ``Good Morning America'' asked El-Baz on Wednesday to evaluate the Park Police photographs. The Park Service and the Boston center both used a grid overlaid on the same 10 photographs.
The difference appears to be the center's method of counting, including ``on-screen tagging'' a technique originally developed for counting sand dunes in the deserts of Egypt and Kuwait. That method, which El-Baz said entails enumerating individuals, was used for parts of the Mall where marchers were standing far enough apart and their individual shadows were visible.
Toward the front of the crowd, marchers were packed much too tightly for the Park Service cameras to distinguish each person's head, El-Baz said in an interview. The center staff assigned a standard value of six people per square meter. In lower-density areas, smaller values were assigned.
No comments:
Post a Comment