Michael Sitar

... Peyto Glacier, at the northern end of the Icefield, has been a part of the national glacier mass balance program since 1966. ... Two survey polygons were flown: SE - NW along the continental divide & SSW - NNE along the axis of Peyto Glacier ...

ABSTRACT The paper presents an evaluation of airborne laser scanning technology for the application of spatial snow depth mapping under varying canopy conditions. Airborne LiDAR (Light Detection And Ranging) surveys were conducted over a small site of variable forest coverage both prior to and during peak snow pack accumulation. Ground measurements of snow depth were collected near the time of the winter LiDAR survey for comparison.

ABSTRACT An airborne scanning LiDAR (light detection and ranging) survey using a small footprint discrete pulse return Airborne Laser Terrain Mapper (ALTM) was conducted over the Utikuma Boreal wetland area ofnorthern Alberta in August 2002. These data were analysed to quantify systematic LiDAR errors in: a) ground surface elevation; and b) vegetation canopy,surface height. Of the vegetation classes, aquatic vegetation was associated with the largest error in LiDAR ground surface definition (+0.15 m, σ= 0.22), likely a result of saturated ground conditions. The largest absoluteerrors in LiDAR canopy surface height were associated withtall vegetation classes. However, the largest relative errors were associated with low shrub (63%) and aquatic vegetation (54%) classes. The openness and orientation of vegetation foliage was thought to enhance laser pulsecanopy,surface penetration in these two classes. Raster canopy,height models (CHMs) systematically underestimated,field validation heights by between 3% (aspens and black spruce) and 64% (aquatic vegetation). It is recommended,that robust LiDAR canopy surface height correction methods be investigated that are universally applicable tovegetation classes of all species and heights.

Abstract An evaluation of airborne lidar (Light Detection And Ranging) technology for snow depth mapping beneath different forest canopy covers (deciduous, coniferous, and mixed) is presented. Airborne lidar data were collected for a forested study site both prior to and during peak snowpack accumulation. Manual field measurements of snow depth were collected coincident with the peak snowpack lidar survey, and a comparison between field and lidar depth estimates was made.