PE&RS March 2003

Cover Image

A small, portable, relatively inexpensive ($30,000 USD) lidar system assembled from off-the-shelf components was used to acquire forest height measurements along linear transects 10s and 100s of kilometers long during the summer of 2000. These height measurements were used to estimate forest volume and aboveground biomass for each of the three counties in Delaware. Shown is a segment of a southbound flightline - south is to the right - in southeastern Delaware. The associated laser height profile is shown above the flight path. The Y axis on the left (north) side of the 1992 color infrared photo is relative height in meters. The yellow numbers printed vertically along the flight line path on the CIR photo are GMT times reported by the laser system’s dGPS once every two seconds. Approximately 1.9 km of laser profiling data are displayed. The payload was carried by a Bell JetRanger (upper right) which transported the 5 kg laser system at 50 m/sec (180 km/hr, ~97 knots) at ~150m above ground level. Height measurements over wetlands, mixedwood, and hardwood forest, agricultural areas, and residential areas are shown. The conifer/mixedwood forest (21:18:15 to 21:18:22 GMT, a 350m segment) has been harvested between the time the CIR photo was taken in 1992 and the June 2000 laser data acquisition.

For more information, contact Ross F. Nelson, NASA/Goddard Space Flight Center, ross@ltpmail.gsfc.nasa.gov.

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

249 Model-Based Conifer Canopy Surface Reconstruction from Photographic Imagery: Overcoming the Occlusion, Foreshortening, and Edge Effects
Yongwei Sheng, Peng Gong, and Gregory S. Biging

The capability of the model-based surface reconstruction approach is extended from recovering the crown surface of a single tree to reconstructing the canopy surface of a tree stand, and is further developed to canopy surface reconstruction for complicated tree stands.

259 True Orthoimage Production for Forested Areas from Large-Scale Aerial Photographs
Yongwei Sheng, Peng Gong, and Gregory S. Biging

An effort for removing occlusion and correcting canopy relief displacement using a canopy surface model (CSM) in true orthoimage generation for forested areas is described.

267 A Portable Airborne Laser System for Forest Inventory
Ross Nelson, Geoffrey Parker, and Milton Hom

A small, relatively inexpensive, first-return, portable airborne laser has been constructed from off-the-shelf components and used to collect over 5,000 km of laser profiling data over Delaware.

275 Spatial Analyses of Logging Impacts in Amazonia Using Remotely Sensed Data
Jane M. Read

Results of analyses of selected spatial methods for characterizing forest canopy disturbance in a reduced- impact logging operation in central Amazonia, using Ikonos and Landsat 7 ETM+ data over two plot sizes, are presented.

283 Mountain Pine Beetle Red-Attack Forest Damage Classification Using Stratified Landsat TM Data in British Columbia, Canada
S.E. Franklin, M.A. Wulder, R.S. Skakun, and A.L. Carroll

Locations of known mountain pine beetle infestation were used to train a maximun-likelihood algorithm; overall clasification accuracy was 73 percent based on an assessment of 360 independent validation points.

289 Sampling Method and Placement: How Do They Affect the Accuracy of Remotely Sensed Maps?
Lucie Plourde and Russell G. Congalton

How the exact placement or location of samples using simple random sampling, stratified random sampling, and systematic sampling affects estimates of accuracy in remotely sensed forest vegetation maps is explored.

299 A Quantitative Assessment of a Combined Spectral and GIS Rule-Based Land-Cover Classification in the Neuse River Basin of North Carolina
Ross S. Lunetta, Jayantha Ediriwickrema, John Iiames, David Johnson, John G. Lyon, Alexa McKerrow, and Andrew Pilant

An accuracy assessment was performed using reference data derived from in situ field measurements and imagery (camera) data.

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