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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Canopy reflectance modeling of forest stand volume

Pilger, Neal, University of Lethbridge. Faculty of Arts and Science January 2004 (has links)
Three-dimensional canopy relectance models provide a physical-structural basis to satellite image analysis, representing a potentially more robust, objective and accurate approach for obtaining forest cover type and structural information with minimal ground truth data. The Geometric Optical Mutual Shadowing (GOMS) canopy relectance model was run in multiple-forward-mode (MFM) using digital multispectral IKONOS satellite imagery to estimate tree height and stand volume over 100m2 homogeneous forest plots in mountainous terrain, Kananaskis, Alberta. Height was computed within 2.7m for trembling aspen and 1.8m fr lodgepole pine, with basal area estimated within 0.05m2. Stand volume, estimated as the product of mean tree height and basal area, had an absolute mean difference from field measurements of 0.85m3/100m2 and 0.61m3/100m2 for aspen and pine, respectively. / xiii, 143 leaves : ill. (some col.) ; 29 cm.
2

Collection of endmembers and their separability for spectral unmixing in rangeland applications

Rolfson, David, University of Lethbridge. Faculty of Arts and Science January 2010 (has links)
Rangelands are an important resource to Alberta. Due to their size, mapping rangeland features is difficult. However, the use of aerial and satellite data for mapping has increased the area that can be studied at one time. The recent success in applying hyperspectral data to vegetation mapping has shown promise in rangeland classification. However, classification mapping of hyperspectral data requires existing data for input into classification algorithms. The research reported in this thesis focused on acquiring a seasonal inventory of in-situ reflectance spectra of rangeland plant species (endmembers) and comparing them to evaluate their separability as an indicator of their suitability for hyperspectral image classification analysis. The goals of this research also included determining the separability of species endmembers at different times of the growing season. In 2008, reflectance spectra were collected for three shrub species (Artemisia cana, Symphoricarpos occidentalis, and Rosa acicularis), five rangeland grass species native to southern Alberta (Koeleria gracilis, Stipa comata, Bouteloua gracilis, Agropyron smithii, Festuca idahoensis) and one invasive grass species (Agropyron cristatum). A spectral library, built using the SPECCHIO spectral database software, was populated using these spectroradiometric measurements with a focus on vegetation spectra. Average endmembers of plant spectra acquired during the peak of sample greenness were compared using three separability measures – normalized Euclidean distance (NED), correlation separability measure (CSM) and Modified Spectral Angle Mapper (MSAM) – to establish the degree to which the species were separable. Results were normalized to values between 0 and 1 and values above the established thresholds indicate that the species were not separable . The endmembers for Agropyron cristatum, Agropyron smithii, and Rosa acicularis were not separable using CSM (threshold = 0.992) or MSAM (threshold = 0.970). NED (threshold = 0.950) was best able to separate species endmembers. Using reflectance data collected throughout the summer and fall, species endmembers obtained within two-week periods were analyzed using NED to plot their separability. As expected, separability of sample species changed as they progressed through their individual phenological patterns. Spectra collected during different solar zenith angles were compared to see if they affected the separability measures. Sample species endmembers were generally separable using NED during the periods in which they were measured and compared. However, Koeleria gracilis and Festuca idahoensis endmembers were inseparable from June to mid-August when measurements were taken at solar zenith angles between 25° – 30° and 45° – 60°. However, between 30° and 45°, Bouteloua gracilis and Festuca idahoensis endmembers, normally separable during other solar zenith angles, became spectrally similar during the same sampling period. Findings suggest that the choice of separability measures is an important factor when analyzing hyperspectral data. The differences observed in the separability results over time also suggest that the consideration of phenological patterns in planning data acquisition for rangeland classification mapping has a high level of importance. / xii, 93 leaves : ill. (some col.) ; 29 cm
3

Remote sensing of montane forest structure and biomass : a canopy relectance model inversion approach

Soenen, Scott, University of Lethbridge. Faculty of Arts and Science January 2006 (has links)
The multiple-forward-mode (MFM) inversion procedure is a set of methods for indirect canopy relectance model inversion using look-up tables (LUT). This thesis refines the MFM technique with regard to: 1) model parameterization for the MFM canopy reflectance model executions and 2) methods for limiting or describing multiple solutions. Forest stand structure estimates from the inversion were evaluated using 40 field validation sites in the Canadian Rocky Mountains. Estimates of horizontal and vertical crown radius were within 0.5m and 0.9m RMSE for both conifer and deciduous species. Density estimates were within 590 stems/ha RMSE for conifer and 310 stems/ha RMSE for deciduous. The most effective inversion method used a variable spectral domain with constrained, fine increment LUTs. A biomass estimation method was also developed using empirical relationships with crown area. Biomass density estimates using the MFM method were similar to estimates produced using other multispectral analysis methods (RMSE=50t/ha). / xvi, 156 leaves : ill. (some col.), maps ; 29 cm.
4

Land-cover mapping in an agriculture zone using simulated Sentinel-2 data

Pryor, Logan S January 2012 (has links)
Remote sensing technologies are used to assist in the mapping and monitoring of land cover in space and time. The European Space Agency’s (ESA) upcoming Sentinel-2 MultiSpectral Instrument (MSI) to be launched in 2013 has improved spatial and spectral properties compared to the current large-swath medium-resolution satellite sensors. Prior to the deployment of future sensors it is important to simulate and test the sensor data to evaluate the sensor's potential performance in producing the existing data products and develop new algorithms. This study simulated Sentinel-2 MSI data from airborne hyperspectral data over an agriculture area in northern Alberta, Canada. The standard Sentinel-2 MSI land-cover product was evaluated by comparing it to one created from the standard Landsat 5 TM and SPOT 5 HRV data products. Furthermore the standard Sentinel-2 MSI water column content band configuration and algorithm was evaluated for atmospheric correction purposes. / xi, 90 leaves : col. ill. ; 29 cm

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