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An interferogram reflecting the motion of Black Rapids Glacier, Alaska, U.S.A., was obtained from two European Remote-sensing Satellite (ERS-1) synthetic-aperture radar (SAR) images, acquired on 22 and 25 January 1992. We investigate whether the interferometric data are quantitatively consistent with terrestrial velocity measurements along three transverse profiles. These terrestrial data are from different years (1987, 1990, 1996) and cover different periods (6-28 April, 23 May-7 July and a whole year) than the SAR interferogram. Terrestrial ice velocity at the date of the SAR imagery is obtained via seasonal and annual corrections that are calculated from other terrestrial velocity measurements available at higher...
Mean stand height is an important parameter for forest volume and biomass estimation in support of monitoring and management activities. Information on mean stand height is typically obtained through the manual interpretation of aerial photography, often supplemented by the collection of field calibration data. In remote areas where forest management practices may not be spatially exhaustive or where it is difficult to acquire aerial photography, alternate approaches for estimating stand height are required. One approach is to use very high spatial resolution (VHSR) satellite imagery (pixels sided less than 1m) as a surrogate for air photos. In this research we demonstrate an approach for modelling mean stand height...
Increasing amounts and types of timely and accurate data are required for monitoring to ensure compliance with natural resource regulatory requirements. This study developed a cost-effective method to partially fulfill these data requirements using super large scale aerial photography (Scale: greater than 1:2,000). Two synchronized, metric, Rolleiflex 70mm (2.76in) cameras mounted 12m (40ft) apart on a rigid platform and carried at 5.6 km/hr (3 knots) by a helicopter collected this high resolution, 3D imagery from Alaska and Washington. The overlapping photo pairs provided 3D views of natural resource objects as fine as twigs. The 12m (40ft) inter-camera distance improved ground visibility between tree crowns of...
Trends in the growing season Moderate Resolution Imaging Spectroradiometer (MODIS) Enhanced Vegetation Index (EVI) time-series were analyzed for the time period from 2000 to 2010 to understand landscape-level patterns of vegetation change in ecosystems of interior Alaska. The analysis compared data-sets for Alaska vegetation cover types, wetland cover classes, wildfire boundaries since the 1940s, permafrost type, and elevation to identify the most likely combination of factors driving regional changes in habitat quality and ecosystem productivity. Approximately 48% of all ecosystem areas in interior Alaska were detected with significant (p < 0.05) positive or negative MODIS growing season EVI trends from 2000 to...
Global products of leaf area index (LAI) usually show large uncertainties in sparsely vegetated areas because the understory contribution is not negligible in reflectance modeling for the case of low to intermediate canopy cover. Therefore, many efforts have been made to include understory properties in LAI estimation algorithms. Compared with the conventional data bank method, estimation of forest understory properties from satellite data is superior in studies at a global or continental scale over long periods. However, implementation of the current remote sensing method based on multi-angular observations is complicated. As an alternative, a simple method to retrieve understory NDVI (NDVIu) for sparse boreal...
This paper analyses a stratospheric injection by deep convection of biomass fire emissions over North America (Alaska, Yukon and Northwest Territories) on 24 June 2004 and its long-range transport over the eastern coast of the United States and the eastern Atlantic. The case study is done using MOZAIC observations of ozone, carbon monoxide, nitrogen oxides (NO sub(x)+PAN) and water vapour during the crossing of the southernmost tip of an upper level trough over the Eastern Atlantic on 30 June 03:00 UTC and 10:00 UTC and in a vertical profile over Washington DC on 30 June 17:00 UTC, and by lidar observations of aerosol backscattering at Madison (University of Wisconsin) on 28 June. Attribution of the plumes to the...
This thesis presents two cost-effective techniques for landslide mapping in large, remote regions. The first technique uses ASTER satellite imagery to characterize and determine landslide distribution for part of the South Nahanni watershed. Results obtained from this study confirm that ASTER images are suitable for regional-scale landslide mapping. The second technique involved the creation of landslide susceptibility models for debris flow and rock/debris slides using logistic regression analysis. Cross validation confirmed the models' success. The debris flow model performed best whereas the rock/debris slide model was only moderately successful. Taken together, the two methods developed in this thesis provide...
Forests are an important global resource, playing key roles in both the environment and the economy. The implementation of quality national monitoring programs is required for the generation of robust national statistics, which in turn support global reporting. Conventional monitoring initiatives based on samples of field plots have proven robust but are difficult and costly to implement and maintain, especially for large jurisdictions or where access is difficult. To address this problem, air photo- and satellite-based large area mapping and monitoring programs have been developed; however, these programs also require ground measurements for calibration and validation. To mitigate this need for ground plot data...