Remote sensing technology has been widely recognized for contributing to emergency response efforts after the World Trade
Center attack on September 11th, 2001. The need to coordinate activities in the midst of a dense, yet relatively small area,
made the combination of imagery and mapped data strategically useful. This paper reviews the role played by aerial photography,
satellite imagery, and LIDAR data at Ground Zero. It examines how emergency managers utilized these datasets, and identifies
significant problems that were encountered. It goes on to explore additional ways in which imagery could have been used, while
presenting recommendations for more effective use in future disasters and Homeland Security applications. To plan adequately
for future events, it was important to capture knowledge from individuals who responded to the World Trade Center attack.
In recognition, interviews with key emergency management and geographic information system (GIS) personnel provide the basis
of this paper. Successful techniques should not be forgotten, or serious problems dismissed. Although widely used after September
11th, it is important to recognize that with better planning, remote sensing and GIS could have played an even greater role.
Together with a data acquisition timeline, an expanded discussion of these issues is available in the MCEER/NSF report “Emergency
Response in the Wake of the World Trade Center Attack; The Remote Sensing Perspective” (Huyck and Adams, 2002) 相似文献
A first-order leveling survey across the northeast part of the Yellowstone caldera in September 1998 showed that the central
caldera floor near Le Hardy Rapids rose 24±5 mm relative to the caldera rim at Lake Butte since the previous survey in September
1995. Annual surveys along the same traverse from 1985 to 1995 tracked progressive subsidence near Le Hardy Rapids at an average
rate of –19±1 mm/year. Earlier, less frequent surveys measured net uplift in the same area during 1923–1976 (14±1 mm/year)
and 1976–1984 (22±1 mm/year). The resumption of uplift following a decade of subsidence was first detected by satellite synthetic
aperture radar interferometry, which revealed approximately 15 mm of uplift in the vicinity of Le Hardy Rapids from July 1995
to June 1997. Radar interferograms show that the center of subsidence shifted from the Sour Creek resurgent dome in the northeast
part of the caldera during August 1992 to June 1993 to the Mallard Lake resurgent dome in the southwest part during June 1993
to August 1995. Uplift began at the Sour Creek dome during August 1995 to September 1996 and spread to the Mallard Lake dome
by June 1997. The rapidity of these changes and the spatial pattern of surface deformation suggest that ground movements are
caused at least in part by accumulation and migration of fluids in two sill-like bodies at 5–10 km depth, near the interface
between Yellowstone's magmatic and deep hydrothermal systems.
Received: 30 November 1998 / Accepted: 16 April 1999 相似文献
Differential GPS (DGPS) and Differential Interferometric Synthetic Aperture Radar (DInSAR) analyses were applied to the Kos-Yali-Nisyros Volcanic Field (SE Hellenic Volcanic Arc) to quantify the ground deformation of Nisyros Volcano. After intense seismic activity in 1996, a GPS network was installed in June 1997 and re-occupied annually up to 2002. A general uplift ranging from 14 to 140 mm was determined at all stations of the network. The corresponding horizontal displacements ranged from 13 to 53 mm. The displacement vectors indicate that the island is undergoing extension towards the East, West and South. A two-source “Mogi” model combined with assumed motion along the Mandraki Fault was constructed to fit the observed deformation. The best-fit model assumes sources at a depth of 5500 m NW of the centre of the island and at 6500 m offshore ESE of Yali Island. DInSAR analysis using four pairs of images taken between May 1995 and September 2000 suggests that deformation was occurring during 1995 before the start of the seismic crisis. An amplitude of at least 56 mm along the slant range appeared for the period 1996 through 1999. This deformation is consistent with the two-source model invoked in DGPS modelling. Surface evidence of ground deformation is expressed in the contemporaneous reactivation of the Mandraki Fault. In addition, a 600 m long N-S trending irregular rupture in the caldera floor was formed between 2001 and 2002. This rupture is interpreted as the release of surface stress in the consolidated epiclastic and hydrothermal sediments of the caldera floor. 相似文献