PE&RS November 2001

Cover Image
This months cover images were lidar generated by TerraPoint, LLC of Houston, Texas using their ALTMS technology.  The upper image is a 3-D contour map in the Swiss Alps, part of a 20,000 sq.km collection in conjunction with Swiss Photo Group, Zurich, Switzerland for the Swiss Department of Agriculture to define forest boundaries and croplands. (See Highlight Article, page 1219) It is generated from a DEM with 2m gridded point spacing using multiple laser returns. Terrain elevations range up to 2000m above sea level and were generally collected at 900 m above ground level while averaging 140 knots per hour from a fixed wing aircraft. The lower images are of the Petronas Towers in Kuala Lumpur, Malaysia and were collected on behalf of MinConsult and Ground Data Solutions also of Kuala Lumpur. The towers have 88 stories and are 452 m above street level; occupied in 1998, they are the worlds tallest towers. The data was collected from a fixed wing airframe at 2,500 ft. above ground level. The formatting and art work for these images were created by Bob Henry, Houston Advance Research Center, Houston, Texas.

For information about these projects, contact: Ronald L. Plaster, Director, US Sales & Marketing, TerraPoint, LLC, 214-571-1602 office, www.TerraPoint.com.

Highlight Articles

1209 Laser Altimetry: From Science to Commercial Lidar Mapping
Martin Flood

1219 Lidar: Transitioning Technologies from Lab to Applications Around the Globe
Ronald L. Plaster  

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

1245 Recognition of Fiducial Surfaces in Lidar Surveys of Coastal Topography
John C. Brock, Asbury H. Sallenger, William B. Krabill, Robert N. Swift, and C. Wayne Wright

A new method for the recognition and mapping of surfaces in coastal landscapes that provide accurate and low variability topographic measurements with respect to airborne lidar surveys is described and demonstrated. 

1261 Land Subsidence Monitoring with Differential SAR Interferometry
Tazio Strozzi, Urs Wegmüller, Luigi Tosi, Gabriele Bitelli, and Volker Spreckels

The accuracy of the subsidence maps produced, the huge SAR data archive starting in 1991, the expected continued availability of SAR data, and the maturity of the required processing techniques lead to the conclusion that differential SAR interferometry is suitable for operational monitoring of land subsidence. 

1271 Remote Sensing of Clear-Water, Shallow, Gravel-Bed Rivers Using Digital Photogrammetry
Richard M. Westaway, Stuart N. Lane, and D. Murray Hicks

The development, application, and evaluation of a two-media refraction correction procedure for the digital photogrammetric survey of submerged riverbed topography is described. 

1283 Robust Surface Matching for Automated Detection of Local Deformations Using Least-Median-of-Squares Estimator
Zhilin Li, Zhu Xu, Minyi Cen, and Xiaoli Ding

Various robust estimators have been evaluataed for matching a surface with local deformation, and it has been found that the least-median-of-squares estimator with the “least height difference” method produce the best results. 

1293 An Accuracy Assessment of Various GIS-Based Viewshed Delineation Techniques
Mark A. Maloy and Denis J. Dean

Actual viewsheds from 11 viewpoints were field surveyed and compared to predicted viewsheds generated using various commonly used elevation data sets, various data models, and various visibility criteria. 

1299 An Airborne Direct Digital Imaging System
Don Light

Aircraft equipped with state-of-the-art digital cameras, dual-channel Global Positioning System receivers, and intertial measurement units collect imagery with position and attitude data that permits geopositioning of each frame without the use of ground surveyed control points. 

Announcements
1222 Digital Elevation Model Technologies and  Applications: The DEM Users Manual
1227 CALL FOR Papers: Characterizing and  Modeling Landscape Dynamics
1258 Scholarships and Awards
1259 Integrating Remote Sensing at the Global, Regional, and Local Scale
Cover 3 ASPRS-ACSM 2002 Conference

Columns & Updates
1225 Direct Georeferencing
1229 Grids & Datums — Public Trust of Survey  & Maps
1231 Headquarters News
1233 Industry News

Departments
1238 Who’s Who in ASPRS
1239 Sustaining Members
1244 Index to Advertisers
1241 Classifieds
1260 Instructions to Authors
1282 Forthcoming Articles
1306 Calendar
1301 Bookstore
1311 Professional Directory
1315 Membership Application

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