Geographic Information Sciences | Open Access Articles

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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A Note On The Temporary Misregistration Of Landsat-8 Operational Land Imager (Oli) And Sentinel-2 Multi Spectral Instrument (Msi) Imagery, James Storey, David P. Roy, Jeffrey Masek, Ferran Gascon, Michael Choate

GSCE Faculty Publications

The Landsat-8 and Sentinel-2 sensors provide multi-spectral image data with similar spectral and spatial characteristics that together provide improved temporal coverage globally. Both systems are designed to register Level 1 products to a reference image framework, however, the Landsat-8 framework, based upon the Global Land Survey images, contains residual geolocation errors leading to an expected sensor-to-sensor misregistration of 38 m (2σ). These misalignments vary geographically but should be stable for a given area. The Landsat framework will be readjusted for consistency with the Sentinel-2 Global Reference Image, with completion expected in 2018. In the interim, users can measure Landsat-to-Sentinel tie …

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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

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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Canopy Height Estimation By Characterizing Waveform Lidar Geometry Based On Shape-Distance Metric, Eric Ariel L. Salas, Geoffrey M. Henebry

GSCE Faculty Publications

There have been few approaches developed for the estimation of height using waveform LiDAR data. Unlike any existing methods, we illustrate how the new Moment Distance (MD) framework can characterize the canopy height based on the geometry and return power of the LiDAR waveform without having to go through curve modeling processes. Our approach offers the possibilities of using the raw waveform data to capture vital information from the variety of complex waveform shapes in LiDAR. We assess the relationship of the MD metrics to the key waveform landmarks—such as locations of peaks, power of returns, canopy heights, and height …

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A Comparison Of Tropical Rainforest Phenology Retrieved From Geostationary (Seviri) And Polar-Orbiting (Modis) Sensors Across The Congo Basin, Dong Yan, Xiaoyang Zhang, Yunyue Yu, Wei Guo

GSCE Faculty Publications

The seasonal and interannual dynamics of tropical rainforests play a critical role in the global carbon cycle and climate change. This paper retrieved and compared land surface phenology from observations acquired by the Spinning Enhanced Visible and Infrared Imager (SEVIRI) onboard geostationary satellites and the Moderate Resolution Imaging Spectroradiometer (MODIS) on polar-orbiting satellites over the Congo Basin. To achieve this,we first retrieved canopy greenness cycles (CGCs) and their transition timing from two-band enhanced vegetation index (EVI2) derived from SEVIRI and MODIS data between 2006 and 2013.We then assessed the influences of SEVIRI and MODIS data quality on the reconstruction of …

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The Influences Of Drought And Land-Cover Conversion On Inter-Annual Variation Of Npp In The Three-North Shelterbelt Program Zone Of China Based On Modis Data, Dailiang Peng, Chaoyang Wu, Bing Zhang, Alfredo Huete, Xiaoyang Zhang, Rui Sun, Liping Lei, Wenjing Huang, Liangyun Liu, Xinjie Liu, Jun Li, Shezhou Luo, Bin Fang

GSCE Faculty Publications

Terrestrial ecosystems greatly contribute to carbon (C) emission reduction targets through photosynthetic C uptake.Net primary production (NPP) represents the amount of atmospheric C fixed by plants and accumulated as biomass. The Three-North Shelterbelt Program (TNSP) zone accounts for more than 40% of China’s landmass. This zone has been the scene of several large-scale ecological restoration efforts since the late 1990s, and has witnessed significant changes in climate and human activities.Assessing the relative roles of different causal factors on NPP variability in TNSP zone is very important for establishing reasonable local policies to realize the emission reduction targets for central government. …

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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

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

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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The Global Landsat Archive: Status, Consolidation, And Direction, Michael A. Wulder, Joanne C. White, Thomas R. Loveland, Curtis E. Woodcock, Alan S. Belward, Warren B. Cohen, Eugene A. Fosnight, Jerad Shaw, Jeffrey G. Masek, David P. Roy

GSCE Faculty Publications

New and previously unimaginable Landsat applications have been fostered by a policy change in 2008 that made analysis-ready Landsat data free and open access. Since 1972, Landsat has been collecting images of the Earth, with the early years of the program constrained by onboard satellite and ground systems, as well as limitations across the range of required computing, networking, and storage capabilities. Rather than robust on-satellite storage for transmission via high bandwidth downlink to a centralized storage and distribution facility as with Landsat-8, a network of receiving stations, one operated by the U.S. government, the other operated by a community …

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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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Computationally Inexpensive Landsat 8 Operational Land Imager (Oli) Pansharpening, Hankui Zhang, David P. Roy

GSCE Faculty Publications

Pansharpening algorithms fuse higher spatial resolution panchromatic with lower spatial resolution multispectral imagery to create higher spatial resolution multispectral images. The free-availability and systematic global acquisition of Landsat 8 data indicate an expected need for global coverage and so computationally efficient Landsat 8 pansharpening. This study adapts and evaluates the established, and relatively computationally inexpensive, Brovey and context adaptive Gram Schmidt component substitution (CS) pansharpening methods for application to the Landsat 8 15 m panchromatic and 30 m red, green, blue, and near-infrared bands. The intensity images used by these CS pansharpening methods are derived as a weighted linear combination …

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Full-Text Articles in Geographic Information Sciences

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

A Note On The Temporary Misregistration Of Landsat-8 Operational Land Imager (Oli) And Sentinel-2 Multi Spectral Instrument (Msi) Imagery, James Storey, David P. Roy, Jeffrey Masek, Ferran Gascon, Michael Choate

GSCE Faculty Publications

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

Canopy Height Estimation By Characterizing Waveform Lidar Geometry Based On Shape-Distance Metric, Eric Ariel L. Salas, Geoffrey M. Henebry

GSCE Faculty Publications

A Comparison Of Tropical Rainforest Phenology Retrieved From Geostationary (Seviri) And Polar-Orbiting (Modis) Sensors Across The Congo Basin, Dong Yan, Xiaoyang Zhang, Yunyue Yu, Wei Guo

GSCE Faculty Publications

GSCE Faculty Publications

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

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 Global Landsat Archive: Status, Consolidation, And Direction, Michael A. Wulder, Joanne C. White, Thomas R. Loveland, Curtis E. Woodcock, Alan S. Belward, Warren B. Cohen, Eugene A. Fosnight, Jerad Shaw, Jeffrey G. Masek, David P. Roy

GSCE Faculty Publications

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

GSCE Faculty Publications

Computationally Inexpensive Landsat 8 Operational Land Imager (Oli) Pansharpening, Hankui Zhang, David P. Roy

GSCE Faculty Publications