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Articles 1 - 8 of 8

Full-Text Articles in Social and Behavioral Sciences

Object-Based Crop Classification With Landsat-Modis Enhanced Time-Series Data, Qingting Li, Cuizhen Wang, Bing Zhang, Linlin Lu Dec 2015

Object-Based Crop Classification With Landsat-Modis Enhanced Time-Series Data, Qingting Li, Cuizhen Wang, Bing Zhang, Linlin Lu

Faculty Publications

Cropland mapping via remote sensing can provide crucial information for agri-ecological studies. Time series of remote sensing imagery is particularly useful for agricultural land classification. This study investigated the synergistic use of feature selection, Object-Based Image Analysis (OBIA) segmentation and decision tree classification for cropland mapping using a finer temporal-resolution Landsat-MODIS Enhanced time series in 2007. The enhanced time series extracted 26 layers of Normalized Difference Vegetation Index (NDVI) and five NDVI Time Series Indices (TSI) in a subset of agricultural land of Southwest Missouri. A feature selection procedure using the Stepwise Discriminant Analysis (SDA) was performed, and 10 optimal …


Modis-Derived Spatiotemporal Changes Of Major Lake Surface Areas In Arid Xinjiang, China, 2000–2014, Qingting Li, Linlin Lu, Cuizhen Wang, Yingkui Li, Yue Sui, Huadong Guo Oct 2015

Modis-Derived Spatiotemporal Changes Of Major Lake Surface Areas In Arid Xinjiang, China, 2000–2014, Qingting Li, Linlin Lu, Cuizhen Wang, Yingkui Li, Yue Sui, Huadong Guo

Faculty Publications

Inland water bodies, which are critical freshwater resources for arid and semi-arid areas, are very sensitive to climate change and human disturbance. In this paper, we derived a time series of major lake surface areas across Xinjiang Uygur Autonomous Region (XUAR), China, based on an eight-day MODIS time series in 500 m resolution from 2000 to 2014. A classification approach based on water index and dynamic threshold selection was first developed to accommodate varied spectral features of water pixels at different temporal steps. The overall classification accuracy for a MODIS-derived water body is 97% compared to a water body derived …


Evaluation Of Three Modis-Derived Vegetation Index Time Series For Dryland Vegetation Dynamics Monitoring, Linlin Lu, Claudia Kuenzer, Cuizhen Wang, Huadong Guo, Qingting Li Jun 2015

Evaluation Of Three Modis-Derived Vegetation Index Time Series For Dryland Vegetation Dynamics Monitoring, Linlin Lu, Claudia Kuenzer, Cuizhen Wang, Huadong Guo, Qingting Li

Faculty Publications

Understanding the spatial and temporal dynamics of vegetation is essential in drylands. In this paper, we evaluated three vegetation indices, namely the Normalized Difference Vegetation Index (NDVI), the Soil-Adjusted Vegetation Index (SAVI) and the Enhanced Vegetation Index (EVI), derived from the Moderate Resolution Imaging Spectroradiometer (MODIS) Surface-Reflectance Product in the Xinjiang Uygur Autonomous Region, China (XUAR), to assess index time series’ suitability for monitoring vegetation dynamics in a dryland environment. The mean annual VI and its variability were generated and analyzed from the three VI time series for the period 2001–2012 across XUAR. Two phenological metrics, start of the season …


Improved Polsar Image Classification By The Use Of Multi-Feature Combination, Lei Deng, Ya-Nan Yan, Cuizhen Wang Apr 2015

Improved Polsar Image Classification By The Use Of Multi-Feature Combination, Lei Deng, Ya-Nan Yan, Cuizhen Wang

Faculty Publications

Polarimetric SAR (POLSAR) provides a rich set of information about objects on land surfaces. However, not all information works on land surface classification. This study proposes a new, integrated algorithm for optimal urban classification using POLSAR data. Both polarimetric decomposition and time-frequency (TF) decomposition were used to mine the hidden information of objects in POLSAR data, which was then applied in the C5.0 decision tree algorithm for optimal feature selection and classification. Using a NASA/JPL AIRSAR POLSAR scene as an example, the overall accuracy and kappa coefficient of the proposed method reached 91.17% and 0.90 in the L-band, much higher …


Modis-Based Fractional Crop Mapping In The U.S. Midwest With Spatially Constrained Phenological Mixture Analysis, Cheng Zhong, Cuizhen Wang, Changshan Wu Jan 2015

Modis-Based Fractional Crop Mapping In The U.S. Midwest With Spatially Constrained Phenological Mixture Analysis, Cheng Zhong, Cuizhen Wang, Changshan Wu

Faculty Publications

Since the 2000s, bioenergy land use has been rapidly expanded in U.S. agricultural lands. Monitoring this change with limited acquisition of remote sensing imagery is difficult because of the similar spectral properties of crops. While phenology-assisted crop mapping is promising, relying on frequently observed images, the accuracies are often low, with mixed pixels in coarse-resolution imagery. In this paper, we used the eight-day, 500 m MODIS products (MOD09A1) to test the feasibility of crop unmixing in the U.S. Midwest, an important bioenergy land use region. With all MODIS images acquired in 2007, the 46-point Normalized Difference Vegetation Index (NDVI) time …


Dreaming Of Dry Land: Environmental Transformation In Colonial Mexico City, Andrew Sluyter Jan 2015

Dreaming Of Dry Land: Environmental Transformation In Colonial Mexico City, Andrew Sluyter

Faculty Publications

No abstract provided.


African Cowboys On The Argentine Pampas: Their Disappearance From The Historical Record, Andrew Sluyter Jan 2015

African Cowboys On The Argentine Pampas: Their Disappearance From The Historical Record, Andrew Sluyter

Faculty Publications

No abstract provided.


Integrating Hands-On Undergraduate Research In An Applied Spatial Science Senior Level Capstone Course, David Kulhavy, Daniel R. Unger, I-Kuai Hung, David Douglass Jan 2015

Integrating Hands-On Undergraduate Research In An Applied Spatial Science Senior Level Capstone Course, David Kulhavy, Daniel R. Unger, I-Kuai Hung, David Douglass

Faculty Publications

A senior within a spatial science Ecological Planning capstone course designed an undergraduate research project to increase his spatial science expertise and to assess the hands-on instruction methodology employed within the Bachelor of Science in Spatial Science program at Stephen F Austin State University. The height of 30 building features estimated remotely with LiDAR data, within the Pictometry remotely sensed web-based interface, and in situ with a laser rangefinder were compared to actual building feature height measurements. A comparison of estimated height with actual height indicated that all three estimation techniques tested were unbiased estimators of height. An ANOVA, conducted …