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Full-Text Articles in Engineering

Validation Of Noaa-Interactive Multisensor Snow And Ice Mapping System (Ims) By Comparison With Ground-Based Measurements Over Continental United States, Christine Chen, Tarendra Lakhankar, Peter Romanov, Sean Helfrich, Al Powell, Reza Khanbilvardi Apr 2012

Validation Of Noaa-Interactive Multisensor Snow And Ice Mapping System (Ims) By Comparison With Ground-Based Measurements Over Continental United States, Christine Chen, Tarendra Lakhankar, Peter Romanov, Sean Helfrich, Al Powell, Reza Khanbilvardi

Publications and Research

In this study, daily maps of snow cover distribution and sea ice extent produced by NOAA’s interactive multisensor snow and ice mapping system (IMS) were validated using in situ snow depth data from observing stations obtained from NOAA’s National Climatic Data Center (NCDC) for calendar years 2006 to 2010. IMS provides daily maps of snow and sea ice extent within the Northern Hemisphere using data from combination of geostationary and polar orbiting satellites in visible, infrared and microwave spectrums. Statistical correspondence between the IMS and in situ point measurements has been evaluated assuming that ground measurements are discrete and continuously …


Using Avhrr-Based Vegetation Health Indices For Estimation Of Potato Yield In Bangladesh, Rahman A., Kaiser Khan, Nir Y. Krakauer, Leonid Roytman, Kogan F. Mar 2012

Using Avhrr-Based Vegetation Health Indices For Estimation Of Potato Yield In Bangladesh, Rahman A., Kaiser Khan, Nir Y. Krakauer, Leonid Roytman, Kogan F.

Publications and Research

We developed a model correlating Advanced Very High Resolution Radiometer (AVHRR)-based Temperature Condition Index (TCI) and Vegetation Condition Index (VCI) with potato yield in Bangladesh. Weekly TCI and VCI Indices for 1993–2005 along with official potato yield statistics were used for model development. We found a strong correlation between inter annual variation in potato yield and TCI and VCI during the critical period of potato growth (vegetative phase and tuber initiation), mid-December to mid-January. Principal component regression (PCR) was used to construct a model to predict potato yield as function of TCI and VCI. The model explained about 75% of …


Using Microwave Brightness Temperature Diurnal Cycle To Improve Emissivity Retrievals Over Land, Hamidreza Norouzi, William Rossow, Marouane Temimi, Catherine Prigent, Marzieh Azarderakhsh, Sid Boukabara, Reza Khanbilvardi Jan 2012

Using Microwave Brightness Temperature Diurnal Cycle To Improve Emissivity Retrievals Over Land, Hamidreza Norouzi, William Rossow, Marouane Temimi, Catherine Prigent, Marzieh Azarderakhsh, Sid Boukabara, Reza Khanbilvardi

Publications and Research

To retrieve microwave land emissivity, infrared surface skin temperatures have been used as surface physical temperature since there is no global information on physical vegetation/soil temperature profiles. However, passive microwave emissions originate fromdeeper layerswith respect to the skin temperature. So, this inconsistency in sensitivity depths between skin temperatures and microwave temperaturesmay introduce a discrepancy in the determined emissivity. Previous studies showed that this inconsistency can lead to significant differences between day and night retrievals of land emissivity which can exceed 10%. This study proposes an approach to address this inconsistency and improve the retrieval of land emissivity using microwave observations …


Analysis Of The Effects Of Snowpack Properties On Satellite Microwave Brightness Temperature And Emissivity Data, Tarendra Lakhankar, Amir E. Azar, Narges Shahroudi, Alfred Powell, Reza Khanbilvardi Jan 2012

Analysis Of The Effects Of Snowpack Properties On Satellite Microwave Brightness Temperature And Emissivity Data, Tarendra Lakhankar, Amir E. Azar, Narges Shahroudi, Alfred Powell, Reza Khanbilvardi

Publications and Research

Spatial variations of snowpack properties are an essential component in flood predictions and water resource management. Satellite microwave remote sensing has shown great potential in retrieving snowpack properties such as: snow depth, snow grain size, and snow density. In this research, we investigate the potential of microwave emissivity which is highly influenced by snowpack properties. Brightness temperature and emissivity data generated from HUT (Helsinki University of Technology) microwave emission of snow model were evaluated with satellite microwave measurements. The comparison of the real measurements (in-situ and satellite) with the modeled results shows that the scattering signature (19GHz-37GHz and 19GHz-85GHz) shows …


Dissemination Of Geological Information In Avoiding Geotechnical Risks Associated With Tunnel Construction: Lessons Learned From Deep Voids In Marble In Lower Manhattan, New York City, Nazrul I. Khandaker, Stanley Schleifer, Masud Ahmed, Leah Scott Oct 2011

Dissemination Of Geological Information In Avoiding Geotechnical Risks Associated With Tunnel Construction: Lessons Learned From Deep Voids In Marble In Lower Manhattan, New York City, Nazrul I. Khandaker, Stanley Schleifer, Masud Ahmed, Leah Scott

Publications and Research

Test boring associated with the recently accomplished City Water Tunnel # 3 in Manhattan, New York City revealed moderately to highly weathered marble with insoluble silicate residues composed mostly of phlogopite, chlorite, and tremolite. Apparent control on the weatherability of the marble was in response to original mineral constituents dominating this lithology. Encountered marble samples ranged between pure calcitic to mixed dolomitic/siliceous types. Fresh marble samples collected from adjacent boring locations revealed characteristic geochemical data: Lime (25-45%), Silica (4-7%), Alumina (1-3%), MgO (5-20%), and LOI (35-42%); compressive strength of unweathered marble varied between 2000-3000 Kg/cm2. Relict foliations with …


The Sensitivity Of Land Emissivity Estimates From Amsr-E As C And X Bands To Surface Properties, Hamid Norouzi, Marouane Temimi, William B. Rossow, Cindy Pearl, M. Azarderakhsh, Reza Khanbilvardi Jan 2011

The Sensitivity Of Land Emissivity Estimates From Amsr-E As C And X Bands To Surface Properties, Hamid Norouzi, Marouane Temimi, William B. Rossow, Cindy Pearl, M. Azarderakhsh, Reza Khanbilvardi

Publications and Research

Microwave observations at low frequencies exhibit more sensitivity to surface and subsurface properties with little interference from the atmosphere. The objective of this study is to develop a global land emissivity product using passive microwave observations from the Advanced Microwave Scanning Radiometer – Earth Observing System (AMSR-E) and to investigate its sensitivity to land surface properties. The developed product complements existing land emissivity products from SSM/I and AMSU by adding land emissivity estimates at two lower frequencies, 6.9 and 10.65 GHz (C- and X-band, respectively). Observations at these low frequencies penetrate deeper into the soil layer. Ancillary data used in …


Bias Correction Of Satellite Rainfall Estimation Using A Radar-Gauge Product, Kibrewossen Tesfagiorgis, Shayesteh E. Mahani, Nir Y. Krakauer, Reza Khanbilvardi Jan 2011

Bias Correction Of Satellite Rainfall Estimation Using A Radar-Gauge Product, Kibrewossen Tesfagiorgis, Shayesteh E. Mahani, Nir Y. Krakauer, Reza Khanbilvardi

Publications and Research

Hourly Satellite Precipitation Estimates (SPEs) may be the only available source of information for operational hydrologic and flash flood prediction due to spatial limitations of radar and gauge products. SPEs are prone to larger systematic errors and more uncertainty sources in comparison with ground based radar and gauge precipitation products. The present work develops an approach to seamlessly blend satellite, radar and gauge products to fill gaps in ground-based data. To mix different rainfall products, the bias of any of the products relative to each other should be removed. The study presents and tests a proposed ensemblebased method which aims …


Brooklyn's Thirst, Long Island's Water: Consolidation, Local Control, And The Aquifer, Jeffrey A. Kroessler Jan 2011

Brooklyn's Thirst, Long Island's Water: Consolidation, Local Control, And The Aquifer, Jeffrey A. Kroessler

Publications and Research

The creation of greater New York City in 1898 promised a solution to the problem of supplying Brooklyn and Queens with water. In the 1850s, the City of Brooklyn tapped ponds and streams on the south side of Queens County, and in the 1880s, dug wells for additional supply. This lowered the water table and caused problems for farmers and oystermen, many of whom sued the city for damages. Ultimately, salt water seeped into some wells from over-pumping. By 1896, Brooklyn’s system had reached its limit. Prevented by the state legislature from tapping the aquifer beneath Suffolk’s Pine Barrens, the …


A Multi-Temporal Analysis Of Amsr-E Data For Flood And Discharge Monitoring During The 2008 Flood In Iowa, Marouane Temimi, Teodosio Lacava, Tarendra Lakhankar, Valerio Tramutoli, Hosni Ghedira, Riadh Ata, Reza Khanbilvardi Jan 2011

A Multi-Temporal Analysis Of Amsr-E Data For Flood And Discharge Monitoring During The 2008 Flood In Iowa, Marouane Temimi, Teodosio Lacava, Tarendra Lakhankar, Valerio Tramutoli, Hosni Ghedira, Riadh Ata, Reza Khanbilvardi

Publications and Research

The objective of this work is to demonstrate the potential of using passive microwave data to monitor flood and discharge conditions and to infer watershed hydraulic and hydrologic parameters. The case study is the major flood in Iowa in summer 2008. A new Polarisation Ratio Variation Index (PRVI) was developed based on a multi-temporal analysis of 37 GHz satellite imagery from the Advanced Microwave Scanning Radiometer (AMSR-E) to calculate and detect anomalies in soil moisture and/or inundated areas. The Robust Satellite Technique (RST) which is a change detection approach based on the analysis of historical satellite records was adopted. A …


Diagnosing Water Variations Within The Amazon Basin Using Satellite Data, Marzieh Azarderakhsh, William B. Rossow, Fabrice Papa, Hamidreza Norouzi, Reza Khanbilvardi Jan 2011

Diagnosing Water Variations Within The Amazon Basin Using Satellite Data, Marzieh Azarderakhsh, William B. Rossow, Fabrice Papa, Hamidreza Norouzi, Reza Khanbilvardi

Publications and Research

The components of the Amazon water budget and their spatiotemporal variability are diagnosed using monthly averaged remote sensing‐based data products for the period September 2002‐December 2006. The large Amazon basin is divided into 14 smaller watersheds, and for each of these sub‐basins, fresh water discharge is estimated from the water balance equation using satellite data products. The purpose of this study is to learn how to apply satellite data with global coverage over the large tropical regions; therefore several combinations of remote sensing estimates including total water storage changes, precipitation and evapotranspiration. The results are compared to gauge‐based measurements and …


Sensitivity Analysis Of B-Factor In Microwave Emission Model For Soil Moisture Retrieval: A Case Study For Smap Mission, Dugwon Seo, Tarendra Lakhankar, Reza Khanbilvardi May 2010

Sensitivity Analysis Of B-Factor In Microwave Emission Model For Soil Moisture Retrieval: A Case Study For Smap Mission, Dugwon Seo, Tarendra Lakhankar, Reza Khanbilvardi

Publications and Research

Sensitivity analysis is critically needed to better understand the microwave emission model for soil moisture retrieval using passive microwave remote sensing data. The vegetation b-factor along with vegetation water content and surface characteristics has significant impact in model prediction. This study evaluates the sensitivity of the b-factor, which is function of vegetation type. The analysis is carried out using Passive and Active L and S-band airborne sensor (PALS) and measured field soil moisture from Southern Great Plains experiment (SGP99). The results show that the relative sensitivity of the b-factor is 86% in wet soil condition and 88% in high vegetated …


Analysis Of Large Scale Spatial Variability Of Soil Moisture Using A Geostatistical Method, Tarendra Lakhankar, Andrew S. Jones, Cynthia L. Combs, Manajit Sengupta, Thomas H. Vonder Haar, Reza Khanbilvardi Jan 2010

Analysis Of Large Scale Spatial Variability Of Soil Moisture Using A Geostatistical Method, Tarendra Lakhankar, Andrew S. Jones, Cynthia L. Combs, Manajit Sengupta, Thomas H. Vonder Haar, Reza Khanbilvardi

Publications and Research

Spatial and temporal soil moisture dynamics are critically needed to improve the parameterization for hydrological and meteorological modeling processes. This study evaluates the statistical spatial structure of large-scale observed and simulated estimates of soil moisture under pre- and post-precipitation event conditions. This large scale variability is a crucial in calibration and validation of large-scale satellite based data assimilation systems. Spatial analysis using geostatistical approaches was used to validate modeled soil moisture by the Agriculture Meteorological (AGRMET) model using in situ measurements of soil moisture from a state-wide environmental monitoring network (Oklahoma Mesonet). The results show that AGRMET data produces larger …


Development Of A Green Roof Environmental Monitoring And Meteorological Network In New York City, Stuart R. Gaffin, Reza Khanbilvardi, Cynthia Rosenzweig Apr 2009

Development Of A Green Roof Environmental Monitoring And Meteorological Network In New York City, Stuart R. Gaffin, Reza Khanbilvardi, Cynthia Rosenzweig

Publications and Research

Green roofs (with plant cover) are gaining attention in the United States as a versatile new environmental mitigation technology. Interest in data on the environmental performance of these systems is growing, particularly with respect to urban heat island mitigation and stormwater runoff control. We are deploying research stations on a diverse array of green roofs within the New York City area, affording a new opportunity to monitor urban environmental conditions at small scales. We show some green roof systems being monitored, describe the sensor selection employed to study energy balance, and show samples of selected data. These roofs should be …


Non-Parametric Methods For Soil Moisture Retrieval From Satellite Remote Sensing Data, Tarendra Lakhankar, Hosni Ghedira, Marouane Temimi, Manajit Sengupta, Reza Khanbilvardi, Reginald Blake Mar 2009

Non-Parametric Methods For Soil Moisture Retrieval From Satellite Remote Sensing Data, Tarendra Lakhankar, Hosni Ghedira, Marouane Temimi, Manajit Sengupta, Reza Khanbilvardi, Reginald Blake

Publications and Research

Satellite remote sensing observations have the potential for efficient and reliable mapping of spatial soil moisture distributions. However, soil moisture retrievals from active microwave remote sensing data are typically complex due to inherent difficulty in characterizing interactions among land surface parameters that contribute to the retrieval process. Therefore, adequate physical mathematical descriptions of microwave backscatter interaction with parameters such as land cover, vegetation density, and soil characteristics are not readily available. In such condition, non-parametric models could be used as possible alternative for better understanding the impact of variables in the retrieval process and relating it in the absence of …


Effect Of Land Cover Heterogeneity On Soil Moisture Retrieval Using Active Microwave Remote Sensing Data, Tarendra Lakhankar, Hosni Ghedira, Marouane Temimi, Amir E. Azar, Reza Khanbilvardi Jan 2009

Effect Of Land Cover Heterogeneity On Soil Moisture Retrieval Using Active Microwave Remote Sensing Data, Tarendra Lakhankar, Hosni Ghedira, Marouane Temimi, Amir E. Azar, Reza Khanbilvardi

Publications and Research

This study addresses the issue of the variability and heterogeneity problems that are expected from a sensor with a larger footprint having homogenous and heterogeneous sub-pixels. Improved understanding of spatial variability of soil surface characteristics such as land cover and vegetation in larger footprint are critical in remote sensing based soil moisture retrieval. This study analyzes the sub-pixel variability (standard deviation of subgrid pixels) of Normalized Difference Vegetation Index and SAR backscatter. Backpropagation neural network was used for soil moisture retrieval from active microwave remote sensing data from Southern Great Plains of Oklahoma. The effect of land cover heterogeneity (number …


Generating Multi-Sensor Precipitation Estimates Over Radar Gap Areas, Shayesteh E. Mahani, Reza Khanbilvardi Jan 2009

Generating Multi-Sensor Precipitation Estimates Over Radar Gap Areas, Shayesteh E. Mahani, Reza Khanbilvardi

Publications and Research

Generating a multi-sensor precipitation product over radar gap area is the objective of the present study. A merging approach is developed to improve Satellite-based Precipitation Estimates (SPE) by merging with ground-based Radar Rainfall (RR) estimates because remote satellites are the only source that can collect information from areas where are inaccessible by ground-based radar and/or rain gauge networks. The merging algorithm is capable of extending radar information from pixels with available RR to their neighboring pixels with no radar information by merging RR with SPE, which is, usually, available for all pixels. SPE is combined with RR using the weighting-based …


Tunnel Geology As Seen By Geologists: Manhattan, New York City, Nazrul I. Khandaker, Stanley Schleifer, Masud Ahmed, Alan R. Slaughter, Belal A. Sayeed, Dorean J. Flores, Mario Jo-Ramirez Oct 2005

Tunnel Geology As Seen By Geologists: Manhattan, New York City, Nazrul I. Khandaker, Stanley Schleifer, Masud Ahmed, Alan R. Slaughter, Belal A. Sayeed, Dorean J. Flores, Mario Jo-Ramirez

Publications and Research

Current exploratory boring operations in and around Manhattan, New York City are providing geologists and geotechnical engineers with a plethora of new and interesting geological information, which has not been previously reported. The rocks encountered, mostly medium to high-grade metamorphic rocks, with both mafic and felsic intrusives, are highly variable in competency and mechanical durability. One of the most frequently encountered rock types is a garnetiferous-muscovite-biotite schist which grades into schistose gneiss and displays a wide variety of structural, compositional, and textural attributes. Metamorphic minerals showing the variable degree of metamorphism include graphite, talc, garnet, kyanite, tourmaline, emory, and occasionally …


Novel Carbon-Carbon Bond Oxidative Cleavage Of Hexabenzyl-Hexaazaisowurtzitane By N-Buono And (Nh4)2ce(No3)6, Xiao-Pei Guan, Hong Yan, Jian-Guang Sun, Yong-Zhong Yu Mar 1999

Novel Carbon-Carbon Bond Oxidative Cleavage Of Hexabenzyl-Hexaazaisowurtzitane By N-Buono And (Nh4)2ce(No3)6, Xiao-Pei Guan, Hong Yan, Jian-Guang Sun, Yong-Zhong Yu

Publications and Research

Treatment of 2,4,6,8,10,12-hexabenzyl-2,4,6,8,10,12-hexaazatetracyclo-[5.5.0.05,9.03,11]dodecane with n-butyl nitrite or ammonium cerium nitrate results in novel C(1)-C(7) oxidative cleavage to give 1,3,4,5,7,8-hexabenzyl-cis-cisoid-cis-hexahydro-1H,5H-diimidazolinium[4,5-b:4′,5′-e]pyrazine dinitrate.