Michael Braukus
Headquarters, Washington          August 29, 2002
(Phone: 202/358-1979)

Carolina Martinez
Jet Propulsion Laboratory, Pasadena, Calif.
(Phone: 818/354-9382)

Marian Gandire
Witten Technologies Inc., Boston
(Phone: 617/236-0019)

Brenda Perez,
Con Edison, New York
(Phone: 212/460-4111)

RELEASE: 02-166


NASA TO PROVIDE SHARPER UNDERGROUND VIEW 
OF WORLD TRADE CENTER AREA

     NASA will apply its image-processing expertise to 
enhance underground radar images of the area around the World 
Trade Center in New York, providing a clearer picture of 
what's beneath the surface.  

"Our image-processing techniques will provide the first 
enhanced subsurface images of the area around 'ground zero,'" 
said Dr. Amir Fijany, principal scientist and supervisor for 
the Ultracomputing Technology Research Group at NASA's Jet 
Propulsion Laboratory (JPL), Pasadena, Calif. "Our goal is to 
pinpoint utility lines and improve the overall sharpness of 
the images."

Witten Technologies, Inc., of Boston, will supply JPL with 
underground images from lower Manhattan created with ground-
penetrating imaging radar in surveys done for Consolidated 
Edison Company of New York, Inc. (Con Edison) in August 2001 
and January 2002.  

Witten used a new technique called underground "radar 
tomography," which resembles satellite radar but rides on the 
back of a truck directly over the site, producing a 3-D 
picture of what's below the surface to depths of about 1.8 
meters (6 feet). Those images have already proved valuable in 
helping reduce the amount of digging needed to maintain dense 
underground utility networks.  

JPL would add another dimension to the images already 
collected by Witten by pinpointing linear features such as 
gas and electrical utility lines. "We have a continuous 
underground image below about 8 acres of streets in lower 
Manhattan, including several streets surveyed before and 
after 9/11," said Michael Oristaglio, chief scientist of 
Witten Technologies. "But some of the most important features 
are fuzzy; they're at the limit of resolution of the radar. 
We are hoping that JPL's expertise in advanced radar-image 
analysis can bring these features into sharp focus."

This partnership is possible through JPL's Technology 
Affiliates Program that allows large and small businesses to 
work with JPL technologists. It is one of several JPL 
technology transfer programs designed to bring the benefits 
of the space program to American industry.  

Witten is providing JPL with data from around the World Trade 
Center area before and after September 11. "Comparing these 
two sets of radar images taken from the same area at two 
different times may enable the team to detect underground 
changes and assess the extent of damage," said Fijany. 

JPL will apply its image-processing and feature-extraction 
techniques to these images. The primary goal will be to 
pinpoint semi-continuous linear features that could 
correspond to buried utility lines such as phone lines, gas 
lines, pipes or other infrastructure. A secondary goal is to 
improve the overall sharpness and appearance of the raw image 
by reducing clutter and enhancing linear features. This 
initial phase is expected to take six months.

Additionally, JPL will conduct tests on three other sets of 
images with increasing level of complexity from other sites 
in Manhattan taken in February and July 2001.

JPL has been conducting remote sensing and image processing 
of Earth and other planets for more than four decades. Fijany 
led a similar assignment in subsurface imaging to detect 
unexploded ordnance for the U.S. Army Corps of Engineers. 
During this assignment, radar data collected by high-altitude 
airborne ground-penetrating synthetic aperture radar was used 
for subsurface imaging. Advanced image-processing techniques 
were then applied to the radar images. 

The results from that work showed this type of remote sensing 
technology could detect very small features below the 
surface. Similar subsurface imaging technology will be 
applied to the images collected by Witten to enhance their 
overall quality.

The California Institute of Technology in Pasadena manages 
JPL for NASA. 

                           -end-