PE&RS September 2002

Cover Image

This image was taken by Pictometry on September 27, 2001 sixteen days after the attacks on the World Trade Center and Pentagon using a 2K by 3K digital camera. It is controlled and geolocated allowing precise photogrammetric measurements of structures and other objects. Numerous response organizations and decision makers used this image and others provided by commercial and government sources to direct search and recovery efforts as well as debris removal. This image was taken from the east looking west. The remains of World Trade Center Building 6 and part of World Trade Center Building 5 are visible at the right side of the image below the inset. The remaining superstructure of the North Tower is visible against Building 6 and extends into the debris pile where the plaza for the World Trade Center once was. The oblique angle afforded by these data complimented other remote sensing data collected on a daily basis shortly after the attack. The NASA Stennis Space Center worked closely with the New York Governor's Office for Technology and the Federal Emergency Management Agency (FEMA) to advise on remote sensing missions and assist in developing solutions to real-time problems during the response effort. (See the Highlight Article on page 870.)

Imagery courtesy of Pictometry. Layout and design by The NASA Stennis Space Center.

Highlight Article

870 Lending A Helping Hand: Using Remote Sensing to Support the Response and Recovery Operations at the World Trade Center
Ray A. Williamson and John C. Baker

Peer-Reviewed Articles (Click the linked titles to see the full abstract)

897 The Role of Soft Classification Techniques in the Refinement of Estimates of Ground Control Point Location
Giles M. Foody

A soft classification, used to provide information on sub-pixel land-cover composition that may be used to direct the estimation of the location of ground control points, is described.

905 A Comparison of Fuzzy vs. Augmented-ISODATA Classification Algorithms for Cloud-Shadow Discrimination from Landsat Images
Assefa M. Melesse and Jonathan D. Jordan

The results show that both techniques are efficient and have an overall accuracy of greater than 80 percent.

913 Techniques for Mapping Suburban Sprawl
Jeanne Epstein, Karen Payne, and Elizabeth Kramer

We conclude that, while the amount of time required to edit and buffer road coverages is significantly higher than that for traditional remote sensing techniques, the improved thematic accuracy, spatial contiguity, and potential future uses of the resulting dataset justifies its use in a state-wide mapping program.

919 Improvement of an Oak Canopy Model Extracted from Digital Photogrammetry
Peng Gong, Xueliang Mei, Gregory S. Biging, and Zuxun Zhang

A digital surface model of oak trees can be improved by correcting errors occurring around the boundaries of tree canopies.

925 Detecting and Measuring Individual Trees Using an Airborne Laser Scanner
Åsa Persson, Johan Holmgren, and Ulf Söderman

An algorithm using high-resolution airborne laser data for capturing tree position, tree height, and crown diameter was evaluated using field measurements.

933 Methods for Measuring Height and Planimetry Discrepancies in Airborne Laserscanner Data
Hans-Gerd Maas

Applying least-squares matching techniques to dense laserscanner data in a TIN structure, strip discrepancies can be determined with centimeter precision for the height coordinate and decimeter precision for the planimetric coordinates.

941 Cloud Mapping from the Ground: Use of Photogrammetric Methods
Gabriela Seiz, Emmanuel P. Baltsavias, and Armin Gruen

The use of modern digital photogrammetric methods to automatically determine the 3D cloud base from a newly developed ground-based stereo imager system is presented.

Announcements
890 Call for Papers - ASPRS 2003 Annual Conference

Columns & Updates
877 Direct Georeferencing (Adobe Acrobat format 74kb)
881 Grids & Datums - The Republic of Latvia
885 Headquarters News
887 Industry News

Departments
885 New Member List
891 Classifieds
892 Calendar
893 Who's Who in ASPRS
894 Sustaining Members
896 Index to Advertisers
904 Instructions to Authors
912 Forthcoming Articles
952 Bookstore
956 Professional Directory
959 Membership Application

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