PE&RS February 2007

This month’s cover image, a digital elevation model (DEM) covering part of the Angelo Costal Range Reserve in California, is provided by Qi Chen from the Center for the Assessment and Monitoring of Forest Resources at UC, Berkeley. The DEM was produced from airborne lidar data using a software called Tiffs (Toolbox for LiDAR Data Filtering and Forest Studies). The raw lidar data have a total size of 2 Gigabytes and the pulse density is about 5 points per m2. The site covers an area of 35 square kilometers.

In an hour, Tiffs accomplished these tasks: 1) filtering the point clouds and separating ground returns and canopy returns, 2) generating digital elevation model (DEM), digital surface model (DSM), and canopy height model (CHM), 3) isolating tree crowns and extracting individual tree height, crown area, and trunk height. The output models (DEM, DSM, and CHM) have a cell size of 2m by 2m. The software was run without tuning individual parameters and the images shown were produced without any manual editing of the point cloud.

The lidar data was courtesy of NCALM at UC, Berkeley.

Highlight Article

109 Airborne Lidar Data Processing and Information Extraction (Adobe PDF 708Kb)
Qi Chen

Columns & Updates
113 In My Opinion...(Adobe PDF 111Kb)
115 Grids and Datums— Tunisian Republic (Adobe PDF 127Kb)
117 Mapping Matters
127 Industry News

Announcements
209 Call for Papers — Artificial Intelligence in Remote Sensing

Departments
118 New Member List
118 Region of the Month
119 Certification List
120 APPLANIX – DIRECT GEOREFERENCING SOLUTIONS (Adobe PDF 501Kb)
122 NOVATEL’S PRECISE THINKING MAKES IT POSSIBLE (Adobe PDF 343Kb)
124 ASPRS Member Champions (Adobe PDF 106Kb)
125 INDUSTRY-WIDE LIDAR DATA WAREHOUSE ANNOUNCEMENT (Adobe PDF 325Kb)
128 Who’s Who in ASPRS
129 Sustaining Member List
131 Instructions to Authors
164 Forthcoming Articles
174 Calendar
209 Classifieds
210 Professional Directory
211 Advertiser Index
212 Membership Application

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

133 Geometric Correction and Digital Elevation Extraction Using Multiple MTI Datasets
Jeffrey A. Mercier, Robert A. Schowengerdt, James C. Storey, and Jody L. Smith

Concepts from Photogrammetric stereo pair elevation extraction have been extended to utilize three or more imagery collects and to provide geometric correction information for a pushbroom sensor.

143 An Experiment Using a Circular Neighborhood to Calculate Slope Gradient from a DEM
Xun Shi, A-Xing Zhu, James Burt, Wes Choi, Rongxun Wang, Tao Pei, Baolin Li, and Chengzhi Qin

Research comparing the slope gradient values calculated using a circular neighborhood with the results from the traditional square neighborhood used in a focal operation on a raster layer.

155 Comparison of Atmospheric Correction Methods in Mapping Timber Volume with Multitemporal Landsat Images in Kainuu, Finland
I. Norjamäki and T. Tokola

The estimation of forest characteristics from an atmospherically corrected Landsat EMT+ mosaic.

165 Estimation of Fuzzy Error Matrix Accuracy Measures Under Stratified Random Sampling
Stephen V. Stehman, Manoj K. Arora, Teerasit Kasetkasem, and Pramod K. Varshney

The formulas for estimating accuracy measures derived from a fuzzy error matrix when stratified random sampling is implemented to obtain the reference data.

175 Filtering Airborne Laser Scanning Data with Morphological Methods
Qi Chen, Peng Gong, Dennis Baldocchi, and Gengxin Xie

A new method for filtering laser scanning data based on morphological methods without slope restrictions, and a method to fill in missing data voids.

187 A Rigorous Model for Spaceborne Linear Array Sensors
Daniela Poli

A rigorous sensor model for the orientation of pushbroom sensors with along-track stereo viewing and the results obtained in various applications.

197 Combining Decision Trees with Hierarchical Objectoriented Image Analysis for Mapping Arid Rangelands
Andrea S. Laliberte, Ed L. Fredrickson, and Albert Rango

Multi-resolution image segmentation was combined with classification trees for mapping shrubs and grasses with QuickBird imagery.