Remote Sensing Commons^™

Mapping Vegetation Productivity Dynamics And Degradation Trends Over East Africa Using A Decade Of Medium Resolution Modis Time-Series Data, Tobias Landmann, Olena Dubovyk

All Peer-Reviewed Publications

This paper aims to characterize spatial and temporal vegetation productivity trends that could be related to land degradation in East Africa. A decade of AQUA/TERRA-Moderate Resolution Imaging Spectroradiometer (MODIS) satellite observations on vegetation chlorophyll activity, or Normalized Differential Vegetation Index (NDVI) data, and 25-km rainfall data from the TRMM passive radar instrument were used for the same observation period of 2000-2011. Linear trends in land cover based Rain Use Efficiencies (RUE) corrected NDVI and cumulative differences of RUE between consecutive years from 2000 to 2011 (that is amplitudes) were derived and investigated for their robustness. The trend maps were overlaid …

Temperature Trends And Urban Heat Island Intensity Mapping Of The Las Vegas Valley, Adam Leland Black

UNLV Theses, Dissertations, Professional Papers, and Capstones

Modified urban climate regions that are warmer than rural areas at night are referred to as Urban Heat Islands or UHI. Islands of warmer air over a city can be 12 degrees Celsius greater than the surrounding cooler air. The exponential growth in Las Vegas for the last two decades provides an opportunity to detect gradual temperature changes influenced by an increasing presence of urban materials. This thesis compares ground based thermometric observations and satellite based remote sensing temperature observations to identify temperature trends and UHI areas caused by urban development.

Analysis of temperature trends between 2000 and 2010 at …

Use Of Ground Penetrating Radar For Determination Ofwater Table Depth And Subsurface Soil Characteristics At Kennedy Space Center, Gideon M. Hengari, Carlton R. Hall, Tim J. Kozusko, Charles R. Bostater

Ocean Engineering and Marine Sciences Faculty Publications

Sustainable use and management of natural resources require strategic responses using non-destructive tools to provide spatial and temporal data for decision making. Experiments conducted at John F. Kennedy Space Center (KSC) demonstrate ground penetrating radar (GPR) can provide high-resolution images showing depth to water tables. GPR data at KSC were acquired using a MALÅ Rough Terrain 100 MHz Antenna. Data indicate strong correlation (R²=0.80) between measured water table depth (shallow monitoring wells and soil auger) and GPR estimated depth. The study demonstrated the use of GPR to detect Holocene and Pleistocene depositional environments such as Anastasia Formation that consists of …

Operational Multi-Angle Hyperspectral Sensing For Feature Detection, Charles R. Bostater, Donald K. Brooks

Ocean Engineering and Marine Sciences Faculty Publications

Remote sensing results of land and water surfaces from airborne and satellite platforms are dependent upon the illumination geometry and the sensor viewing geometry. Correction of pushbroom hyperspectral imagery can be achieved using bidirectional reflectance factors (BRF's) image features based upon their multi-angle hyperspectral signatures. Ground validation of features and targets utilize non-imaging sensors such as hemispherical goniometers. In this paper, a new linear translation based hyperspectral imaging goniometer system is described. Imagery and hyperspectral signatures obtained from a rotation stage platform and the new linear non-hemispherical goniometer system shows applications and a multi-angle correction approach for multi-angle hyperspectral pushbroom …

Land Surface Phenologies And Seasonalities Using Cool Earthlight In Mid-Latitude Croplands, Woubet G. Alemu, G. M. Henebry

Natural Resource Management Faculty Publications

Phenology deals with timing of biotic phenomena and seasonality concerns temporal patterns of abiotic variables. Studies of land surface phenology (LSP) and land surface seasonality (LSS) have long been limited to visible to near infrared (VNIR) wavelengths, despite degradation by atmospheric effects and solar illumination constraints. Enhanced land surface parameters derived from passive microwave data enable improved temporal monitoring of agricultural land surface dynamics compared to the vegetation index data available from VNIR data. LSPs and LSSs in grain growing regions of the Volga River Basin of Russia and the spring wheat belts of the USA and Canada were characterized …

Study Of Feasability For Phase Difference Extraction Using Software Defined Radio In Location Analysis, Paul Miller

Masters Theses

Here is a method for using the phase of an HF radio signal for use in location analysis. This computation is implemented in a software defined radio processing block in the GNU Radio environment. The signals analyzed are received by an Ettus Research USRP SDR. We created a phase analysis system called WMU Rootsync, which compares the roots of a received signal to the roots of a generated reference signal for the phase analysis. This research describes a prototype method for phase analysis only. Future projects may use these ideas differently than presented here. We intend for future projects to …

Remote Sensing Of Green Leaf Area Index In Maize And Soybean: From Close-Range To Satellite, Anthony L. Nguy-Robertson

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

This dissertation seeks to explore alternative methodologies for estimating green leaf area index (LAI) and crop developmental stages. Specifically this research [1] developed an approach for creating a Moderate Resolution Imaging Spectroradiometer (MODIS) high spatial resolution product for estimating green LAI on the base of data collected using two different close-range sensors. It was determined that the vegetation indices (VIs) Wide Dynamic Range Vegetation Index (WDRVI) and Enhanced Vegetation Index 2 (EVI2) were capable of accurate estimation of green LAI from MODIS 250 m data using models developed from hyperspectral (RMSE < 0.69 m² m^-2; CV < 33%) or multispectral sensors (RMSE < 0.69 m² m^-2; …

Evaluation Of A Coupled Event-Driven Phenology And Evapotranspiration Model For Croplands In The United States Northern Great Plains, V. Kovalskyy, G. M. Henebry, D. P. Roy, B. Adusei, M. Hansen, G. Senay, D. M. Mocko

Natural Resource Management Faculty Publications

A new model coupling scheme with remote sensing data assimilation was developed for estimation of daily actual evapotranspiration (ET). The scheme consists of the VegET, a model to estimate ET from meteorological and water balance data, and an Event Driven Phenology Model (EDPM), an empirical crop specific model trained on multiple years of flux tower data transformed into six types of environmental forcings that are called “events” to emphasize their temporally discrete character, which has advantages for modeling multiple contingent influences. The EDPM in prognostic mode supplies seasonal trajectories of normalized difference vegetation index (NDVI); whereas in diagnostic mode, it …

Using Remotely Sensed Data To Detect Tamarisk Along Colorado’S San Miguel River, William E. Johnson

Geography and the Environment: Graduate Student Capstones

Tamarisk, an invasive tree native to Eurasia, has become widespread in river corridors across the southwestern United States. Accused of excessive water consumption and degradation of native habitats, it has been the target of extensive eradication and restoration efforts. Identifying its ever-changing distribution and extent benefits natural resource managers tasked with planning and prioritizing invasive plant management activities.

The use of GIS tools and remotely sensed data offers the potential to speed and improve our ability to locate tamarisk distributions. This project searches for tamarisk by classifying land cover vegetation (including tamarisk) based on spectral reflectance values from three-band natural …

Enhancing Remote Sensing For Agriculture Using Small Unmanned Aerial Systems: San Diego, Ca, As A Test Case, Colin Kubera

Geography and the Environment: Graduate Student Capstones

The development of small Global Positioning System (GPS) antennas and microprocessors has propelled the advancement of affordable Small Unmanned Aerial Systems (SUASs), which will dramatically expand the remote sensing field, making timely, high-resolution imagery readily available. The low cost and simple operation of SUASs makes them an attractive option for agriculture. Flying a SUAS 400 ft above ground level (AGL) in a flight path that allows for significant image overlap can yield sub- 5cm resolution imagery, which in turn can be mosaicked and used for multispectral imagery analysis. With results rivaling the most advanced commercial imaging sensors, SUASs can be …

Archaeological Prospecting Using Historic Aerial Imagery: Investigations In Northeast And Southwest Arkansas, Emily Jean Bitely

Graduate Theses and Dissertations

This research investigates the potential of historic aerial photographs as a tool for archaeological site prospecting. Craighead and Mississippi Counties in northeast Arkansas and areas adjacent to the Red and Little Rivers in southwest Arkansas were chosen as study areas. These regions have undergone significant changes in the past few decades and were expected to yield visible types of archaeological sites. Historic aerial images of these areas were obtained through the U.S. Geological Survey's EarthExplorer database (http://earthexplorer.usgs.gov/). These images were processed using Agisoft PhotoScan Professional to produce extensive regional orthoimages.

Using the Arkansas Archeological Survey's Automated Management of Archeological Site …

Classification Of Satellite Time Series-Derived Land Surface Phenology Focused On The Northern Fertile Crescent, Brian Embree Bunker

Graduate Theses and Dissertations

Land surface phenology describes events in a seasonal vegetation cycle and can be used in a variety of applications from predicting onset of future drought conditions, to revealing potential limits of historical dry farming, to guiding more accurate dating of archeological sites. Traditional methods of monitoring vegetation phenology use data collected in situ. However, vegetation health indices derived from satellite remote sensor data, such as the normalized difference vegetation index (NDVI), have been used as proxy for vegetation phenology due to their repeated acquisition and broad area coverage. Land surface phenology is accessible in the NDVI satellite record when images …

Agricultural Production And Stability Of Settlement Systems In Upper Mesopotamia During The Early Bronze Age (Third Millennium Bce), Tuna Kalayci

Graduate Theses and Dissertations

This study investigates the relationship between rainfall variation and rain-fed agricultural production in Upper Mesopotamia with a specific focus on Early Bronze Age urban settlements. In return, the variation in production is used to explore stability of urban settlement systems. The organization of the flow of agricultural goods is the key to sustaining the total settlement system.

The vulnerability of a settlement system increases due to the increased demand for more output from agricultural lands. This demand is the key for the success of urbanization project. However, without estimating how many foodstuffs were available at the end of a production …

The Evaluation Of Water Storage In Death Valley Using Grace Satellite Data, Maile Sweigart

UNLV Theses, Dissertations, Professional Papers, and Capstones

As drought conditions spread across the United States, concerns over water supplies, water use, and water management policies are growing and possible contributing environmental factors are continually being scrutinized. This thesis examines Death Valley as an analog for Southern Nevada and utilizes NASA EOS data, combined with ancillary climate data, to assess the effect of decadal climate variability on groundwater storage in the Death Valley area. Historical climate data, combined with satellite imagery observations, were compiled and calculated for analyses. Conclusions derived from statistical analyses infer trends between GRACE (Gravity Recovery and Climate Experiment) satellite data and fluctuating levels of …

Trail Mapping From Space: New Recreation Mapping At Bogus Basin Ski Area, Jenna Duffin, Cherilyn Blender, Dondi Black, Chrissy Weiser, Remington Buyer, Rick Raymondi, Bruce Slice, Alisha Pena, Jim Edgemon, Brian Himes, Steve Rogers, Patrick Watsons, Dave Wofford

College of Arts and Sciences Poster Presentations

Research Question: Can a comprehensive, accurate, and detailed map of recreational trails be produced without stepping foot in the field? Remote sensing is "reconnaissance at a distance" (Colwell, 1966). Mapping is a three step process: 1.) basemap assembly, 2.) cartographic interpretation, 3.) review & correction. While a simple concept, remote sensing has traditionally been the left to the experts due to the high skill set and specialized computing equipment required to complete even the most rudimentary data preparation and processing tasks. Today, Google Earth, the National Agricultural Imagery Program (1m NAIP), global 30m digital elevation data (DEM), desktop ArcGIS, and …

The Global Availability Of Landsat 5 Tm And Landsat 7 Etm+ Land Surface Observations And Implications For Global 30m Landsat Data Product Generation, V. Kovalskyy, David P. Roy

GSCE Faculty Publications

With the advent of the free U.S. Landsat data policy it is now feasible to consider the generation of global coverage 30 m Landsat data sets with temporal reporting frequency similar to that provided by the monthly Web Enabled Landsat (WELD) products. A statistical Landsat metadata analysis is reported considering more than 800,000 Landsat 5 TM and Landsat 7 ETM + acquisitions obtained from the U.S. Geological Survey (USGS) Earth Resources Observation and Science (EROS) Center archive. The global monthly probabilities of acquiring a cloud-free land surface observation for December 1998 to November 2001 (2000 epoch) and from December 2008 …

An Environmental And Historical Study Of The Nipomo Mesa Region, Jason C. Carr

Social Sciences

No abstract provided.

Proximal Sensing As A Means Of Characterizing Phragmites Australis, Travis Yeik

Department of Geography: Dissertations, Theses, and Student Research

Phragmites australis is an invasive wetland weed found throughout much of the United States. Documenting and mapping the growth and spread of this emergent macrophyte can be an important step in developing and implementing successful management strategies. Characterizing the phenology of a vegetation species with a sensor capable of hyperspectral resolution, positioned at close proximity to the canopy of interest, is often a first step necessary for understanding the basic species-specific reflectance patterns, and for quantifying the manner in which light interacts with the plants comprising particular communities. Spectral data over a P. australis canopy were collected during 22 …

Allometric Scaling And Resource Limitations Model Of Tree Heights: Part 2. Site Based Testing Of The Model, Sungho Choi, Xiliang Ni, Yuli Shi, Sangram Ganguly, Gong Zhang, Hieu V. Duong, Michael A. Lefsky, Marc Simard, Sassan S. Saatchi, Shihyan Lee, Wenge Ni-Meister, Shilong Piao, Chunxiang Cao, Ramakrishna R. Nemani, Ranga B. Myneni

Publications and Research

The ultimate goal of this multi-article series is to develop a methodology to generate continuous fields of tree height and biomass. The first paper demonstrated the need for Allometric Scaling and Resource Limitation (ASRL) model optimization and its ability to generate spatially continuous fields of tree heights over the continental USA at coarse (1 km) spatial resolution. The objective of this second paper is to provide an assessment of that approach at site scale, specifically at 12 FLUXNET sites where more accurate data are available. Estimates of tree heights from the Geoscience Laser Altimeter System (GLAS) waveform data are used …

A Study Of So2 Emissions And Ground Surface Displacements At Lastarria Volcano, Antofagasta Region, Northern Chile, Lucie Guihem Krewcun

Dissertations, Master's Theses and Master's Reports - Open

Lastarria volcano (Chile) is located at the North-West margin of the `Lazufre' ground inflation signal (37x45 km²), constantly uplifting at a rate of ~2.5 cm/year since 1996 (Pritchard and Simons 2002; Froger et al. 2007). The Lastarria volcano has the double interest to be superimposed on a second, smaller-scale inflation signal and to be the only degassing area of the Lazufre signal. In this project, we compared daily SO2 burdens recorded by AURA's OMI mission for 2005-2010 with Ground Surface Displacements (GSD) calculated from the Advanced Synthetic Aperture Radar (ASAR) images for 2003-2010.

We found a constant maximum displacement rate …