Spelling suggestions: "subject:"remote sensing"" "subject:"demote sensing""
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CROPS WATER STATUS QUANTIFICATION USING THERMAL AND MULTISPECTRAL SENSING TECHNOLOGIESYan Zhu (12238322) 20 April 2022 (has links)
<p>Thermal and multispectral imagery can provide users with
insights into the water stress status and evapotranspiration demand of crops.
However, traditional platforms, such as satellites, for these thermal and
multispectral sensors are limited in their usefulness due to low spatial and
temporal resolution. Small unmanned aircraft system (UAS) have the potential to
have similar sensors installed and provide canopy temperature and reflectance
information at spatial and temporal resolutions more useful for crop
management; however, most of the existing research on the calibration or the estimation
of water status were established based on the satellite platforms either for
the sensors calibration or water status quantification. There is, therefore, a
need to develop methods specifically for UAS-mounted sensors. In this research,
a pixel-based calibration and an atmospheric correction method based on
in-field approximate blackbody sources were developed for an uncooled thermal
camera, and the higher accurate vegetative temperature acquired after
calibration was used as inputs to an algorithm developed for high-resolution
thermal imagery for calculating crop latent heat flux. At last, a thermal index
based on the Bowen ratio is proposed to quantify the water deficit stress in a
crop field, along with this, a method for plot-level analysis of various
vegetation and thermal indices have been demonstrated to illustrate its broad
application to genetic selection. The objective was to develop a workflow to
use high-resolution thermal and multispectral imagery to derive indices that
can quantify crops water status on a plot level which will facilitate the
research related to breeding selection.</p>
<p>The camera calibration method can effectively reduce the
root mean square error (RMSE) and variability of measurements. The pixel-based
thermal calibration method presented here was able to reduce the measurement
uncertainty across all the pixels in the images, thus improving the accuracy
and reducing the between-pixel variability of the measurements. During field
calibration, the RMSE values relative to ground reference targets for two
flights in 2017 were reduced from 6.36°C to 1.24°C and from 4.56°C to 1.32°C,
respectively. The latent heat flux estimation algorithm yields an RMSE of 65.23 W/m<sup>2</sup>
compared with the ground reference data acquired from porometer. The Bowen
ratio has a high correlation with drought conditions quantified using the soil
moisture index, stomatal conductance, and crop water stress index (CWSI), which
indicates the potential of this index to be used as a water deficit stress
indicator. The thermal and multispectral indices on a plot level displayed will
facilitate the breeding selection.</p>
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Using Landsat TM Imagery to Monitor Vegetation Change Following Flow Restoration to the Lower Owens River, CaliforniaBross, Lesley Crandell 15 December 2015 (has links)
Rehabilitating river corridors to restore valuable riparian habitat consumes significant resources from both governments and private companies. Given these considerable expenditures, it is important to monitor the progress of such projects. This study evaluated the utility of using Landsat Thematic Mapper remotely-sensed data from 2002 and 2009 to monitor vegetation change induced by instream flow restoration to the Lower Owens River in central California. This study compared the results of an unsupervised classification with an NDVI threshold classification to appraise the resources required and effectiveness of each analysis method. The results were inspected by creating standard remote sensing accuracy error matrices and by correlating landscape pattern metrics with bird indicator species. Both sets of classified maps show a noticeable increase in riparian vegetation in the study area following flow restoration in 2006, indicating an improvement of the quality of bird habitat. The study concluded that analyzing vegetation change using the unsupervised classification technique required more effort, expert knowledge, and supplementary data than using the NDVI threshold method. If these prerequisites are met, the output from the unsupervised classification process produces a more precise map of land cover change than the NDVI threshold method. However, if an analyst is lacking either resources or ground verification data, the NDVI threshold technique is capable of providing a generalized, but still valid evaluation of vegetation change. This conclusion is supported by higher correlations between indicator bird species under the unsupervised classification method than were found with the NDVI threshold method.
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Passive microwave snow mapping in QuebecXiao, Renmeng January 1997 (has links)
No description available.
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Methane Plume Detection Using Passive Hyper-Spectral Remote SensingBarnhouse, Willard D., Jr. 03 November 2005 (has links)
No description available.
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Assessing biophysical characteristics of grassland from spectral measurementsWeiser, Russell L. January 1985 (has links)
Call number: LD2668 .T4 1985 W44 / Master of Science / Agronomy
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Using remote sensing, in-situ measurements and data visualisation to investigate tidewater glaciers behaviour in GreenlandDrocourt, Yoann January 2014 (has links)
The aims of this thesis was to participate in the improvement of the current knowledge of tidewater glaciers' behaviour in Greenland. This was achieved by a multi-scale and multi-disciplinary approach.
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A Light Detecting and Ranging (LiDAR) and Global Positioning System (GPS) Study of the Truckee Meadows, NV. Quaternary Fault Mapping with ArcGIS, 3D Visualization and Computational Block Modeling of the Greater Reno areaBrailo, Courtney M. 04 August 2016 (has links)
<p> The Truckee Meadows (Reno, NV) sits in a tectonically complex area of western Nevada, where Walker Lane-style transtension is dominant throughout the region. A new Light Detection and Ranging (LiDAR) study focuses on the Truckee Meadows region of western Nevada, including the Reno/Sparks metropolitan area in Washoe County. We use the airborne LiDAR imagery (1485 sq. km) to create high quality, bare-earth topographic maps that were previously unattainable in vegetated, populated or alpine terrain. This approach gives us an opportunity to improve fault maps that may be outdated or incomplete in the area. Here we provide LiDAR imagery of a large section of Washoe County and an updated fault map of the greater Truckee Meadows region. </p><p> We also use this new LiDAR survey of the Truckee Meadows and nearby basins to constrain geometry, length, distribution, and slip rates along faults imaged by this new dataset. Estimated slip rates are compared to those derived from a geodetic block model constrained by Global Positioning Station (GPS) data to test for consistency. GPS station data and geologic mapping show that both east-west oriented extension and northwest-oriented right-lateral strike slip accommodate transtension as a backdrop for tectonics studies of region, with some northeast-oriented left-lateral strike slip. This study aims to better understand how this transtension is partitioned along remapped faults and newly identified structures in this urban setting, as the framework for strain accommodation in this area remains poorly understood. </p><p> Faults with normal offset were measured along strike using bare-earth LiDAR returns to determine the amount of vertical separation across geomorphic surfaces, and then converted to extension assuming a fault dip of 60 (+/-10) degrees. Since the primary geomorphic surfaces in this region are the result of Sierra Nevadan glacial outwash episodes, we use previously published geologic maps to link each surface to an associated date. When integrated across several basin perpendicular transects within the Mt. Rose pediment, we calculate a total extension rate of 0.87 (+0.40/-0.48) mm/yr for the southern Truckee Meadows basin. Integrated slip rates from fault scarp offsets are within the bounds of 1.23 (+/-0.70) mm/yr suggested by geodetic modeling. Block modeling highlights that north-striking faults primarily accommodate east-west extension, and so northwest-striking faults and/or block rotations must accommodate the northwest-directed shear seen in GPS velocities. This trend is bolstered by the discovery of a new northwest-oriented fault on Peavine Mountain 6 km east of the Mogul (2008) seismicity trend. Our study provides further evidence that the Truckee Meadows sits at a critical transition from north-striking normal faults in the southern part of the basin to northwest-oriented strike-slip faults to the north, an observation that mimics regional tectonics and geomorphology of the adjacent Lake Tahoe/Truckee system to the west.</p>
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Controls on the calving rate of north west Svalbard glaciers from satellite remote sensingMansell, Damien Trevor January 2011 (has links)
No description available.
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Estimating aerosol properties using CHRIS/PROBADavies, William Huw January 2012 (has links)
No description available.
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SEA SURFACE SCATTERED GPS SIGNAL DETECTION AND APPLICATIONYi-qiang, Zhang, Qi-shan, Zhang, Dong-kai, Yang, Bo-chuan, Zhang, Rong-lei, Hu, Zi-wei, Li 10 1900 (has links)
ITC/USA 2005 Conference Proceedings / The Forty-First Annual International Telemetering Conference and Technical Exhibition / October 24-27, 2005 / Riviera Hotel & Convention Center, Las Vegas, Nevada / Background and advantages of GPS based Remote Sensing are introduced, characteristics of forward scattered GPS signal such as polarization change, cross-correlation power variation, code delay due to the wave travel distance difference between direct and scattered signal, and cross-correlation power expansion due to sea surface roughness are discussed in detail. Working principle of the self-developed delay-mapping receiver is also presented. First data collection campaign is done at Inshore of BOHAI ocean with the delay-mapping receiver mounted on an airplane. Results show that the reflected signals has much variation than the direct signals, the code delay of the reflected signals varies as the receiver height and satellite elevation angle changes and expansion of the cross-correlation due to the wind driven surface was also demonstrated.
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