Friday, February 22, 2008
Could SAR (synthetic aperture radar) reveal 911 evidence?
NASA TO PROVIDE SHARPER UNDERGROUND VIEW OF WORLD TRADE CENTER AREA
SpatialNews Press Release
Aug 30, 2002 Feb 27, 2003
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.
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.
Well, this was about five years ago and who knows if this study was completed or if the results now exist? But it would be really interesting to know if there have been any SAR images released of the World Trade Center after the disaster. Especially those using long wave lengths that in some cases can map all the way to bed rock. In the absence of evidence, most of which was either hauled away to the dump or smelted, the radar images could possibly contain some clues.
Development and Application of Small Spaceborne Synthetic Aperture Radars (1998)
The Committee on Earth Studies (CES) of the Space Studies Board is a standing committee charged with examining all areas of remote sensing of the Earth from space for civilian and related purposes. The charter includes the satellite-based Earth observation programs of the National Aeronautics and Space Administration (NASA) and the National Oceanic and Atmospheric Administration (NOAA), as well as the merged polar-orbiting environmental satellites of NOAA and the former Defense Meteorological Satellite Program. In 1995, at the request of NASA's Office of Earth Science (formerly Office of Mission to Planet Earth), the committee began a two-part study on issues related to the development and utility of spaceborne synthetic aperture radar (SAR).
The potential of SAR for Earth science commercial and civil applications is being advanced by several satellite systems, including Shuttle-based SAR flights (SIR [Shuttle Imaging Radar]-A, SIR-B, SIR-C/X-SAR1) and the European Space Agency's (ESA's) ERS-1 and ERS-2. Significant contributions are also being realized from Japan's JERS-1 and Canada's Radarsat. Future systems such as ESA's Advanced Synthetic Aperture Radar (ASAR) and Japan's Ministry of International Trade and Industry (MITI) SAR-2 and Phased Array type L-band Synthetic Aperture Radar (PALSAR), an instrument proposed for the Advanced Land Observing Satellite (ALOS), promise to add even more data and processing knowledge to the global pool of SAR experience (Table 1.1). Aircraft support data from NASA's AIRSAR, Germany's E-SAR, and the Netherlands' PHARUS, among others, are used to complement these space measurements but also have helped to advance general understanding of radar reflection from the ground. These airborne systems continue to validate earlier NASA and commercial airborne radar applications and to expand understanding of signal-terrain interactions.
Nevertheless, the development of satellite SAR systems has lagged behind electro-optical systems popularized by the Landsat program inaugurated in 1972. The Landsat paradigm reoriented the remote sensing community toward detection of temporal change and away from the 1960s paradigm of spectral analysis of landscapes. The inertia generated by more than a decade of such focus translates today into a nation whose familiarity with SAR data lags far behind its understanding of data sets derived from sensors operating in the visible near-infrared (VNIR) and thermal infrared (TIR) spectra. Data from all spectral regions, including the microwave region, produce unique and, in some cases, vital information for Earth system science. Determination of the potential information content, however, and means of extracting that information from SAR