• Title/Summary/Keyword: Environmental sensing

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Selection and Utilization of Satellite Imagery for Environmental Assessment in Arid Regions - in the Kuche Area, Tarim Basin, China

  • Wuyi, Yu;Wentong, Dong;Jianjun, Guo;Xiaoping, Qi;Werle, Dirk;Bruce, Grant;Boivin, Tom
    • Proceedings of the KSRS Conference
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    • 2003.11a
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    • pp.1390-1392
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    • 2003
  • The arid regions of western China are currently the focus of extensive exploration and development. This paper reports on recent experience gained by Chinese and Canadian project team members in the use of a variety of Earth observation satellite imagery for oil exploration and environmental assessment exercises in the Kuche area of Xinjiang. Through careful archival data selection and more recent data acquisition schemes, we have established several time series of MODIS, Landsat and Radarsat imagery in order to obtain a better understanding for daily, seasonal as well as decadal changes of the natural environment as well as man-made environmental features.

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Analysis on Wind Profile Characteristics in a Sublayer of Atmospheric Boundary Layer over a Semi-Complex Terrain - LIDAR Remote Sensing Campaign at Pohang Accelerator Laboratory (준복잡지형 대기경계층 저층 풍속분포 특성분석 - 포항가속기 라이다 원격탐사 캠페인을 중심으로)

  • Kim, Hyun-Goo
    • Journal of Environmental Science International
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    • v.21 no.2
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    • pp.145-152
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    • 2012
  • The mean wind speed and turbulence intensity profiles in the atmospheric boundary layer were extracted from a LIDAR remote sensing campaign in order to apply for CFD validation. After considering the semi-steady state field data requirements to be used for CFD validation, a neutral atmosphere campaign period, in which the main wind direction and the power-law exponent of the wind profile were constantly maintained, was chosen. The campaign site at the Pohang Accelerator Laboratory, surrounded by 40~50m high hills, with an apartment district spread beyond the hills, is to be classified as a semi-complex terrain. Nevertheless, wind speed profiles measured up to 100m above the ground fitted well into a theoretical-experimental logarithmic-law equation. The LIDAR remote-sensing data of the sub-layer of the atmospheric boundary layer has been proven to be superior to the data obtained by conventional extrapolation of the wind profile with 2 or 3 anemometer measurements.

Distribution of Surface Temperature and Chlorophyll-a in Lake Soyang using Remote Sensing Techniques (원격탐사기법에 의한 소양호의 표층수온과 엽록소 분포)

  • Jeong, Jong-Chul
    • Journal of Environmental Impact Assessment
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    • v.9 no.3
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    • pp.177-183
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    • 2000
  • The Landsat Thematic Mapper (TM) has suggested that spatial and spectral characteristics would be suited to evaluate water quality of lake. But, TM has not been commonly used for the analysis of in-land water quality, such as surface water temperature, chlorophyll-a, suspended sediments, and Secchi depth in domestic research. This paper summarizes the analysis of Landsat 5 - TM image collected on 22 Feb 1996 for evaluation of chlorophyll-a and surface temperature in the Lake Soyang. And, field measurements collected in the Lake Soyang were used to obtain water optical algorithms for calibration of satellite data. It is concluded that we can assess chlorophyll-a with remote sensing reflectance and surface temperature with thermal band in lake Soyang. However, surface temperature calculated with thermal band of Landsat TM are underestimated. Relationship between remote sensing reflectance and chlorophyll-a using the ratio of TM band 1 and band 3 is as follows; Y = 17.206 - 6.4711 * (Rrs(band1) / Rrs(band3)) $R^2$=0.8762 and, using the ratio of TM band 1 and band 2 as follows; Y = 57.77 - 35.771 * (Rrs(band1) / Rrs(band2)) $R^2$=0.8317.

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The effect of non-synchronous sensing on structural identification and its correction

  • Feng, Zhouquan;Katafygiotis, Lambros
    • Smart Structures and Systems
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    • v.18 no.3
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    • pp.541-568
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    • 2016
  • The goal of this study is to investigate the effect of non-synchronous sensing when using wireless sensors on structural identification and to attempt correcting such errors in order to obtain a better identification result. The sources causing non-synchronous sensing are discussed first and the magnitudes of such synchronization errors are estimated based on time stamps of data samples collected from Imote2 sensors; next the impact of synchronization errors on power spectral densities (PSDs) and correlation functions of output responses are derived analytically; finally a new method is proposed to correct such errors. In this correction method, the corrected PSDs of output responses are estimated using non-synchronous samples based on a modified FFT. The effect of synchronization errors in the measured output responses on structural identification and the application of this correction method are demonstrated using simulation examples. The simulation results show that even small synchronization errors in the output responses can distort the identified modal and stiffness parameters remarkably while the parameters identified using the proposed correction method can achieve high accuracy.

Noncontact strain sensing in cement-based material using laser-induced fluorescence from nanotube-based skin

  • Meng, Wei;Bachilo, Sergei M.;Parol, Jafarali;Weisman, R. Bruce;Nagarajaiah, Satish
    • Structural Monitoring and Maintenance
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    • v.9 no.3
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    • pp.259-270
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    • 2022
  • This study explores the use of the recently developed "strain-sensing smart skin" (S4) method for noncontact strain measurements on cement-based samples. S4 sensors are single-wall carbon nanotubes dilutely embedded in thin polymer films. Strains transmitted to the nanotubes cause systematic shifts in their near-infrared fluorescence spectra, which are analyzed to deduce local strain values. It is found that with cement-based materials, this method is hampered by spectral interference from structured near-infrared cement luminescence. However, application of an opaque blocking layer between the specimen surface and the nanotube sensing film enables interference-free strain measurements. Tests were performed on cement, mortar, and concrete specimens with such modified S4 coatings. When specimens were subjected to uniaxial compressive stress, the spectral peak separations varied linearly and predictably with induced strain. These results demonstrate that S4 is a promising emerging technology for measuring strains down to ca. 30 𝜇𝜀 in concrete structures.

Spectral Reflectance Characteristics for Five Soils at Chungbuk Prefecture and Tideland Soil Using Remote Sensing Technology (원격탐사(RS) 기법을 이용한 충북지역 5개 토양과 갯벌토양의 분광반사특성)

  • Park, Jong-Hwa;Shin, Yong-Hee;Lee, Sang-Hyuk
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.6 no.1
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    • pp.34-40
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    • 2003
  • The deterioration of agricultural environment, which is characterized by dryness and desertification of land, is one of the main reasons which explain the recent decrease of land productivity. To solve these environmental problems, it is very important to make clear the mechanism between soil, water, vegetation and temperature. The main objective of this study is to provide a soil surface information, which represent a soil reflectance spectrum, by remote sensing technology. The soil reflectance of the soil was measured using a spectro-radiometer in the wavelength range from 300nm to 1100nm. The results suggest that the reflectance properties of soils are related to their mineral composition and soil moisture. Increasing soil moisture resulted in an decrease in the rate of reflectance which leads to parallel curves of soil reflectance spectra.

Basic Study of Weaving Structure and Durability for Fabric-type ECG Sensor Design (직물형 ECG센서 설계를 위한 제직구조 및 내구성에 대한 기초연구)

  • Ryu, Jong-Woo;Jee, Young-Joo;Kim, Hong-Jae;Yoon, Nam-Sik
    • Textile Coloration and Finishing
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    • v.23 no.3
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    • pp.219-226
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    • 2011
  • Recently, study of functional clothing for vital sensing is focused on improving conductivity and decreasing resistance, in order to enhance the electrocardiogram(ECG) sensing accuracy and obtained stable environmental durability on operation condition. In this study, four ECG fabrics that having different componnt yarns and weaving structures were produced to analyze their environmental durabilities and electric properties under general operation conditions including different physical and chemical stimulation. For outstanding electric properties and physical properties, the optimized ECG sensing fabric should consist of a fabric of 2 up 3 down twill structure containing 210de silver-coated conductive yarns and polyester yarn in warp and weft directions respectively. The selected fabric has $0.11{\Omega}$ which is relative lower resistance than otherwisely produced fabrics under ECG measurement condition. And it has 7% stable resistance changes under 25% strain and repeated strain.

Sustainable Fresh Water Resources Management in Northern Kuwait-A Remote Sensing View From Raudatain Basin

  • Saif ud din;Dousari Ahmad AI;Ghadban Abdulnabi AI
    • Proceedings of the KSRS Conference
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    • 2005.10a
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    • pp.153-164
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    • 2005
  • The paper presents time and cost effective remote sensing technology to estimate recharge potential of fresh water shallow aquifers for their sustainable management in arid ecosystem. Precipitation measurement of Raudatain Basin in Kuwait from TRMM data has been made and integrated with geological, geomorphological and hyrological data, to estimate the recharge potential of the basin. The total potential recharge to the area is estimated as 333.964 MCM annually. The initial losses are estimated at $60\%$ of the net precipitation .The net available quantity for recharge is 133.58 MCM. For sustainable management of the ground water resources, recharge wells have been proposed in the higher order streams to augment the Raudatain aquifer in Kuwait. If the available quantity of precipitation can be successfully utilized, it will reduce considerable pressure on desalination, which is leading to increased salinity off the coast in Arabian Gulf.

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