Riparian zone showing shading by streamside trees. Note the 
dense canopy and understory on the left side may make it 
very difficult for small-footprint lidar to obtain reflections 
from the ground.LVIS in detecting the ground over 99% of 
the time in Sequoia National Forest in California and at least 
90% of the time in the dense rainforests of La Selva 
Biological Research Station, Costa Rica (Blair et al., 1999). 
5 USES 
The different capabilities of these lidar classes give rise to 
different current and potential uses (Table 4). Small-footprint 
lidars are used primarily for creation of DTMs. These can be 
for road, rail or pipeline right-of-ways, open pit mines, and 
other uses including more recently, surveys of cities that 
include accurate building positions. Change detection is an 
emerging capability of small-footprint lidars and development 
of this capability in urban areas is occurring (Murakami et al., 
1999). Creation of DTMs under forests and other vegetation 
is still a challenge. Most companies that offers lidar services 
    
   
    
   
    
   
   
   
    
   
   
    
    
    
   
    
    
    
    
    
  
International Archives of Photogrammetry and Remote Sensing, Vol. 32, Part 3W14, La Jolla, CA, 9-11 Nov. 1999 
have developed this capability, though details are closely 
guarded. Additionally, approaches to creating DTMs have 
been developed in Europe at universities (Axelsson, 1999; 
Kraus & Pfeifer, 1998). Vegetation height and volume have 
been measured with good success using small-footprint 
(Jensen et al., 1987; Naesset, 1997a; Naesset, 1997b) and 
large foot-print lidars (Lefsky et al., 1999; Means et al., 
1999). Forestry applications of small-footprint lidar have a 
bright future that is currently being explored. 
Future uses 
Data fusion Integration of lidar data with image data offers 
great potential for applications in feature recognition and 
forestry because the two types of information are so 
complementary. Lidar provides structural information, such 
as height, cover density and vertical distribution, while 
imagery provides information on composition such as roof 
type, landcover type, species groups and proportions of 
broadleaves conifers and shrubs, herbs or grass. Progress 
made in integrating lidar with raster imagery to make 3-D 
Table 4. Uses of Two Different Types of Lidar Systems. 
  
Small-footprint, discrete return 
Large-footprint, waveform return” 
  
Current uses 
  
— DTMs: right-of-ways for new & existing roads, high- 
voltage electric power lines (pre-construction, line sag, 
vegetation encroachment), pipelines, mines, landfills, etc. 
— Urban/suburban surveys, quantitative 3-D descriptions 
including vegetation, buildings 
— Change detection of surveyed features 
— Forest tree height, stand volume 
— Integration with raster imagery and airphotos 
— DTMs and topography: glaciers, volcanoes (hazards 
assessment, erosion, accretion), extensive areas 
— Change detection of surveyed features 
— Forest stand height, canopy cover, biomass, basal area, leaf 
area, including dense vegetation 
  
Potential future uses and developments 
  
— Forest biomass, canopy cover, wildland fuels 
floor and channel morphology (above water) 
— Wildlife habitat 
— Agricultural field drainage, crop height development 
— Standards for accuracy and performance 
—Co-collection with co-registered imagery using digital 
cameras, multi- & hyperspectral sensors 
— More automated DTM creation and integration with 
imagery 
  
— Global coverage of topography, ice sheets, vegetation 
height & roughness 
— River/stream: riparian vegetation (height, shade), valley  — Integration and coregistration with raster imagery 
  
  
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