Ground based LIDAR, August 24, 2011 (South Monument)

Ground based LIDAR, August 24, 2011 (North Monument)

LIDAR image of World Trade Center April 2010: Click to enlarge

LIDAR data July 1, 2000 LIDAR data September 19, 2001


Photograph and LIDAR image, double exposure
Click to enlarge
  July 2000 to September 2001 elevation difference
Click to enlarge
  FDNY Article location dataset: March 26, 2002
Click to enlarge



Dr. Sean Ahearn talks about Charting Ground Zero on FoxNews, Sept. 6, 2011
Click to view

  Charting Ground Zero: Featured on WPIX News,
originally aired Feb 2001
Click to view



  EarthData Segment, MSNBC
"Out of the Rubble"
oringinally aired Nov 2001
Click to view
  History Channel: WTC Special, featuring Sean Ahern and LIDAR images
Click to view



<< back to exhibitions

Charting Ground Zero:
Ten Years After

September 7 - October 23, 2011
Opening reception: Wednesday, Sept 7, 6-8pm

The City of New York and the Center for the Advanced Research of Spatial Information (CARSI) of Hunter College-CUNY, in collaboration with Woodward Gallery, proudly presents "Charting Ground Zero Ten Years After." This exhibition provides an extensive aerial and ground overview of the World Trade Center site before, just after September 11th and the sites evolution over the last decade. It uses the latest scientific advances in mapping technology and cartographic representation, to show the transformation of the site. The mapping and spatial analysis technologies played a crucial role in helping the city assess damage, monitor the progress of recovery, and safely deploy personnel and equipment in the disaster zone. Those same technologies are used to show how the site has evolved over the last decade.

Remote-sensing technology used to create the maps included aerial photography, laser-based instruments called LIDAR (light detection and ranging), and thermal sensors. Mounted on planes, LIDAR penetrated the heavy smoke rising from the devastated area and captured the first clear images of the scene. Thermal imaging was used to determine where fires were still smoldering and, over time, the movement of these "hot spots" throughout the area.  New LIDAR images taken in 2010 will reveal extremely fine detail of the 9/11 development site.

As part of a broader effort involving the City's Office of Emergency Management's Mapping and Data Center and Hunter College's CARSI lab, directed by Professor Sean Ahearn, a team of Geo-spatial scientists analyzed the data, then created the many maps used by the city to monitor the changes at ground zero and to speed in recovery. The "before" images of the World Trade Center site, which will be included in the exhibition, were generated from the NYCMap (pronounced "nice map"), a database of highly detailed geographic information on the entire city, accurate to within 18 inches. Created over a period of five years, the map was a joint project of DoITT, the Department of Environmental Protection, and Hunter's CARSI lab. The later images were produced with very high resolution LIDAR taken in the spring of 2010 by Sanborn Map Company with funding from NYC DCAS. Ground-based LIDAR images were collected on August 24, 2011 by the Computer Vision Laboratory of Hunter College - CUNY, Director Professor Ioannis Stamos.

This exhibition organized by Woodward Gallery has traveled the country.  It was broadcast on Channel 11, MSNBC, and the History Channel originally. Now including the advances made ten years after, Woodward welcomes “Charting Ground Zero” back to New York for a final public view then will donate it to the Memorial Museum at Ground Zero for their permanent installation. Esri Inc. of Redlands, CA is a generous sponsor for this exhibition.

This exhibition is now a part of the permanent collection at the National September 11
Memorial and Museum

Click to view Charting Ground Zero: Ten Years After press release.

133 Eldridge St NYC 10002 | 212.966.3411 |