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Physical Sciences and Mathematics Commons

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Full-Text Articles in Physical Sciences and Mathematics

Improving The Accuracy Of Cosmic-Ray Neutron Probe Estimate Of Soil Water Content Using Multiple Detectors And Remote Sensing Estimates Of Vegetation, Xiaochen Dong Dec 2017

Improving The Accuracy Of Cosmic-Ray Neutron Probe Estimate Of Soil Water Content Using Multiple Detectors And Remote Sensing Estimates Of Vegetation, Xiaochen Dong

School of Natural Resources: Dissertations, Theses, and Student Research

The recently developed Cosmic-ray Neutron Probe (CRNP) for estimating soil water content (SWC) fills a critical measurement gap between point scale methods and large scale measurements collected from remote sensing. CRNP works by measuring the change in low-energy neutron intensity over time. However, the accuracy of CRNP to measure SWC is well known to be affected by other hydrogen sources (e.g. soil organic content, atmospheric water vapor, vegetation and surface water). This study focuses on the influence of rapidly growing vegetation in agricultural fields on the accuracy of the CRNP method. Here we use data from three long-term CRNP study …


Assessing A Multi-Platform Data Fusion Technique In Capturing Spatiotemporal Dynamics Of Heterogeneous Dryland Ecosystems In Topographically Complex Terrain, Peter J. Olsoy, Jessica Mitchell, Nancy F. Glenn, Alejandro N. Flores Oct 2017

Assessing A Multi-Platform Data Fusion Technique In Capturing Spatiotemporal Dynamics Of Heterogeneous Dryland Ecosystems In Topographically Complex Terrain, Peter J. Olsoy, Jessica Mitchell, Nancy F. Glenn, Alejandro N. Flores

Geosciences Faculty Publications and Presentations

Water-limited ecosystems encompass approximately 40% of terrestrial land mass and play a critical role in modulating Earth’s climate and provisioning ecosystem services to humanity. Spaceborne remote sensing is a critical tool for characterizing ecohydrologic patterns and advancing the understanding of the interactions between atmospheric forcings and ecohydrologic responses. Fine to medium scale spatial and temporal resolutions are needed to capture the spatial heterogeneity and the temporally intermittent response of these ecosystems to environmental forcings. Techniques combining complementary remote sensing datasets have been developed, but the heterogeneous nature of these regions present significant challenges. Here we investigate the capacity of one …


Regional Sensitivities Of Seasonal Snowpack To Elevation, Aspect, And Vegetation Cover In Western North America, Nancy F. Glenn Aug 2017

Regional Sensitivities Of Seasonal Snowpack To Elevation, Aspect, And Vegetation Cover In Western North America, Nancy F. Glenn

Geosciences Faculty Publications and Presentations

In mountains with seasonal snow cover, the effects of climate change on snowpack will be constrained by landscape-vegetation interactions with the atmosphere. Airborne lidar surveys used to estimate snow depth, topography, and vegetation were coupled with reanalysis climate products to quantify these interactions and to highlight potential snowpack sensitivities to climate and vegetation change across the western U.S. at Rocky Mountain (RM), Northern Basin and Range (NBR), and Sierra Nevada (SNV) sites. In forest and shrub areas, elevation captured the greatest amount of variability in snow depth (16–79%) but aspect explained more variability (11–40%) in alpine areas. Aspect was most …


Assessment Of Nasa Airborne Laser Altimetry Data Using Ground-Based Gps Data Near Summit Station, Greenland, Kelly M. Brunt, Robert L. Hawley, Eric R. Lutz, Michael Studinger Mar 2017

Assessment Of Nasa Airborne Laser Altimetry Data Using Ground-Based Gps Data Near Summit Station, Greenland, Kelly M. Brunt, Robert L. Hawley, Eric R. Lutz, Michael Studinger

Dartmouth Scholarship

A series of NASA airborne lidars have been used in support of satellite laser altimetry missions. These airborne laser altimeters have been deployed for satellite instrument development, for spaceborne data validation, and to bridge the data gap between satellite missions. We used data from ground-based Global Positioning System (GPS) surveys of an 11 km long track near Summit Station, Greenland, to assess the surface–elevation bias and measurement precision of three airborne laser altimeters including the Airborne Topographic Mapper (ATM), the Land, Vegetation, and Ice Sensor (LVIS), and the Multiple Altimeter Beam Experimental Lidar (MABEL). Ground-based GPS data from the monthly …