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Physical and Environmental Geography Commons™

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Geographic Information Sciences

South Dakota State University

GSCE Faculty Publications

Series

Articles 1 - 8 of 8

Full-Text Articles in Physical and Environmental Geography

Using The 500 M Modis Land Cover Product To Derive A Consistent Continental Scale 30 M Landsat Land Cover Classification, Hankui Zhang, David P. Roy Aug 2017

Using The 500 M Modis Land Cover Product To Derive A Consistent Continental Scale 30 M Landsat Land Cover Classification, Hankui Zhang, David P. Roy

GSCE Faculty Publications

Classification is a fundamental process in remote sensing used to relate pixel values to land cover classes present on the surface. Over large areas land cover classification is challenging particularly due to the cost and difficulty of collecting representative training data that enable classifiers to be consistent and locally reliable. A novel methodology to classify large volume Landsat data using high quality training data derived from the 500 m MODIS land cover product is demonstrated and used to generate a 30 m land cover classification for all of North America between 20°N and 50°N. Publically available 30 m global monthly …

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Examination Of The Potential Of Terrestrial Laser Scanning And Structure-From-Motion Photogrammetry For Rapid Nondestructive Field Measurement Of Grass Biomass, Sam D. Cooper, David P. Roy, Crystal B. Schaaf, Ian Paynter May 2017

Examination Of The Potential Of Terrestrial Laser Scanning And Structure-From-Motion Photogrammetry For Rapid Nondestructive Field Measurement Of Grass Biomass, Sam D. Cooper, David P. Roy, Crystal B. Schaaf, Ian Paynter

GSCE Faculty Publications

Above ground biomass (AGB) is a parameter commonly used for assessment of grassland systems. Destructive AGB measurements, although accurate, are time consuming and are not easily undertaken on a repeat basis or over large areas. Structure-from-Motion (SfM) photogrammetry and Terrestrial Laser Scanning (TLS) are two technologies that have the potential to yield precise 3D structural measurements of vegetation quite rapidly. Recent advances have led to the successful application of TLS and SfM in woody biomass estimation, but application in natural grassland systems remains largely untested. The potential of these techniques for AGB estimation is examined considering 11 grass plots with …

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Landsat 5 Thematic Mapper Reflectance And Ndvi 27-Year Time Series Inconsistencies Due To Satellite Orbit Change, Hankui Zhang, David P. Roy Dec 2016

Landsat 5 Thematic Mapper Reflectance And Ndvi 27-Year Time Series Inconsistencies Due To Satellite Orbit Change, Hankui Zhang, David P. Roy

GSCE Faculty Publications

The Landsat 5 Thematic Mapper (TM) sensor provided the longest single mission terrestrial remote sensing data record but temporally sparse station keeping maneuvers meant that the Landsat 5 orbit changed over the 27 year mission life. Long-term Landsat 5 TM reflectance inconsistencies may be introduced by orbit change induced solar zenith variations combined with surface reflectance anisotropy, commonly described by the Bi-directional Reflectance Distribution Function (BRDF). This study quantifies the local overpass time and observed solar zenith angle changes for all the Landsat 5 TM images available at two latitudinally separated locations along the same north-south Landsat path (27) in …

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Characterization Of Landsat-7 To Landsat-8 Reflective Wavelength And Normalized Difference Vegetation Index Continuity, David P. Roy, V. Kovalskyy, Hankui Zhang, Eric F. Vermote, Lin Yan Dr., Sanath Sathyachandran Kumar, Alexey V. Egorov Nov 2016

Characterization Of Landsat-7 To Landsat-8 Reflective Wavelength And Normalized Difference Vegetation Index Continuity, David P. Roy, V. Kovalskyy, Hankui Zhang, Eric F. Vermote, Lin Yan Dr., Sanath Sathyachandran Kumar, Alexey V. Egorov

GSCE Faculty Publications

At over 40 years, the Landsat satellites provide the longest temporal record of space-based land surface observations, and the successful 2013 launch of the Landsat-8 is continuing this legacy. Ideally, the Landsat data record should be consistent over the Landsat sensor series. The Landsat-8 Operational Land Imager (OLI) has improved calibration, signal to noise characteristics, higher 12-bit radiometric resolution, and spectrally narrower wavebands than the previous Landsat-7 Enhanced Thematic Mapper (ETM +). Reflective wavelength differences between the two Landsat sensors depend also on the surface reflectance and atmospheric state which are difficult to model comprehensively. The orbit and sensing geometries …

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An Automated Approach For Sub-Pixel Registration Of Landsat-8 Operational Land Imager (Oli) And Sentinel-2 Multi Spectral Instrument (Msi) Imagery, Lin Yan, David P. Roy, Hankui Zhang, Jian Li, Haiyan Huang Jun 2016

An Automated Approach For Sub-Pixel Registration Of Landsat-8 Operational Land Imager (Oli) And Sentinel-2 Multi Spectral Instrument (Msi) Imagery, Lin Yan, David P. Roy, Hankui Zhang, Jian Li, Haiyan Huang

GSCE Faculty Publications

Moderate spatial resolution satellite data from the Landsat-8 OLI and Sentinel-2A MSI sensors together offer 10 m to 30 m multi-spectral reflective wavelength global coverage, providing the opportunity for improved combined sensor mapping and monitoring of the Earth’s surface. However, the standard geolocated Landsat-8 OLI L1T and Sentinel-2A MSI L1C data products are currently found to be misaligned. An approach for automated registration of Landsat-8 OLI L1T and Sentinel-2A MSI L1C data is presented and demonstrated using contemporaneous sensor data. The approach is computationally efficient because it implements feature point detection across four image pyramid levels to identify a sparse …

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A General Method To Normalize Landsat Reflectance Data To Nadir Brdf Adjusted Reflectance, David P. Roy, Hankui Zhang, Junchang Ju, Jose Luis Gomez-Dans, Philip E. Lewis, Crystal Barker B. Schaaf, Qingsong Sun, Jian Li, Haiyan Huang, V. Kovalskyy Apr 2016

A General Method To Normalize Landsat Reflectance Data To Nadir Brdf Adjusted Reflectance, David P. Roy, Hankui Zhang, Junchang Ju, Jose Luis Gomez-Dans, Philip E. Lewis, Crystal Barker B. Schaaf, Qingsong Sun, Jian Li, Haiyan Huang, V. Kovalskyy

GSCE Faculty Publications

The Landsat satellites have been providing spectacular imagery of the Earth's surface for over 40 years. However, they acquire images at view angles ±7.5° from nadir that cause small directional effects in the surface reflectance. There are also variations with solar zenith angle over the year that can cause apparent change in reflectance even if the surface properties remain constant. When Landsat data from adjoining paths, or from long time series are used, a model of the surface anisotropy is required to adjust all Landsat observations to a uniform nadir view (primarily for visual consistency, vegetation monitoring, or detection of …

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Conterminous United States Crop Field Size Quantification From Multi-Temporal Landsat Data, Lin Yan Dr., David P. Roy Jan 2016

Conterminous United States Crop Field Size Quantification From Multi-Temporal Landsat Data, Lin Yan Dr., David P. Roy

GSCE Faculty Publications

Agricultural field size is indicative of the degree of agricultural capital investment, mechanization and labor intensity, and it is ecologically important. A recently published automated computational methodology to extract agricultural crop fields from weekly 30 m Web Enabled Landsat data (WELD) time series was refined and applied to a year of Landsat 5 Thematic Mapper (TM) and Landsat 7 Enhance Thematic Mapper Plus (ETM +) acquisitions for all of the conterminous United States (CONUS). For the first time, spatially explicit CONUS field size maps and derived information are presented. A total of 4,182,777 fields were extracted with mean and median …

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A Contemporary Decennial Examination Of Changing Agricultural Field Sizes Using Landsat Time Series Data, Emma V. White, David P. Roy Apr 2015

A Contemporary Decennial Examination Of Changing Agricultural Field Sizes Using Landsat Time Series Data, Emma V. White, David P. Roy

GSCE Faculty Publications

Field size distributions and their changes have not been studied over large areas as field size change datasets are not available. This study quantifies agricultural field size changes in a consistent manner using Landsat satellite data that also provide geographic context for the observed decadal scale changes. Growing season cloud-free Landsat 30 m resolution images acquired from 9 to 25 years apart were used to extract field object classifications at seven sites located by examination of a global agricultural yield map, agricultural production statistics, literature review, and analysis of the imagery in the US Landsat archive. High spatial resolution data …

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