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Hindawi Publishing CorporationInternational Journal of Microwave Science and TechnologyVolume 2013 Article ID 950862 9 pageshttpdxdoiorg1011552013950862

Research ArticlePermittivity and Backscattering Coefficient of DieselOil-Contaminated Soil at C Band (53GHz)

Nima Ahmadian1 Sayeh Hasan2 and OmPrakash Narayan Calla3

1 Faculty of Natural Science and Mathematics Institute of Geography and Geology University of GreifswaldFriedr-Ludwig-Jahn-Strasse 16 17487 Greifswald Germany

2Agrosphere Institute (IBG-3) Institute of Bio-Geosciences (IBG) Forschungszentrum Juumllich GmbH ICG-4 52425 Juumllich Germany3 International Center for Radio Science Plot No 1 Rano Ji Ka Bagh Khokariya Bera Nayapura MandoreJodhpur-342304 India

Correspondence should be addressed to Nima Ahmadian ahmadianngmailcom

Received 26 May 2012 Revised 16 October 2012 Accepted 18 December 2012

Academic Editor Wenlong He

Copyright copy 2013 Nima Ahmadian et al is is an open access article distributed under the Creative Commons AttributionLicense which permits unrestricted use distribution and reproduction in any medium provided the original work is properlycited

Studying the behavior of soil contaminated by diesel requires the measurement and calculation of electrical parameters such aspermittivity and backscattering coefficient It is also necessary to study the physical parameters such as surface roughness eintent of this paper is to present a broad and updated overview of the diesel oil contaminated soil emphasizing permittivity andscattering coefficient that are involved in determining anddetecting the rate atwhich and extent towhichhydrocarbons contaminatethe soil and environmentemeasurement of permittivity and the calculations of backscattering coefficient values weremade withdifferent amounts of diesel oil contamination and different incident angles in 5∘ intervals ranging from 10∘ to 80∘ for both horizontaland vertical polarization at C bande values of scattering coefficient for different look angles (25∘ 30∘ 35∘ 40∘ 45∘ 50∘ and 55∘)were calculated and are suitable for comparison with data generated from other remote sensing platforms Accurate electricalparameter measurements of soil contamination and recognition of their dependence on physical and chemical composition areinteresting and can support using microwave remote sensing instruments to observe the earth

1 Introduction

Improved understanding of spatial variation of soil surfacecharacteristics such as soil contamination texture and con-stituents is critical in remote sensing Microwave remotesensing data are function not only of the technical parametersof the sensor but also of the geometric forms and electricalproperties of the objects on the earth such as permittivityand backscattering coefficient [1] e radar backscatteringcoefficient (120590120590∘) from soil surface depends primarily onthe surface roughness and the permittivity of the soil Italso represents the scattering behavior of an object at agiven frequency incident angle and polarization and it isdened directly in terms of the incident and scattered elds[2]

Microwave techniques can be implemented to determinethe extent and the distribution structure of an oil spill on

land Diesel spills in soil cause pollution that can be toxic forbiological particles living in the soil [3] Soil contaminationis caused by the presence of man-made chemicals or otheralteration in the natural soil environment e averagetotal worldwide annual release of petroleum (oils) from allknown sources to the environment (land and ocean) hasbeen estimated at 13 million tons [4] Land-based sourcescontamination typically arises from the rupture of under-ground storage tanks application of pesticides percolationof contaminated surface water to subsurface strata oil andfuel dumping and leaching of wastes from landlls or directdischarge of industrial wastes to the soil Pollution of the soilwith petroleum and renery products is one of the factorsexpressing anthropopression is type of pollution is aserious problem due to its toxicity widespread presence andcomplex nature Contamination of soils with crude oil andrenery products is becoming an ever increasing problem

2 International Journal of Microwave Science and Technology

Petrol stations garages that service cars and tractors andseaport are the major locations where soil is polluted byrenery products [5] Other areas of concern are miningand distribution of petroleum-based products [6ndash8] Heavyuse of machinery in agriculture leads to high consumptionof diesel oil Negligence while transporting collecting orstoring renery products together with unsatisfactory carewhile the disposing of old or used petroleum products leadto considerable pollution of the natural environment [9]Spillage of used motor oils such as diesels or jet fuels con-taminates our natural environment with hydrocarbons [10]Soil contamination with diesel and engine oils is becominga major environmental problem as the usage of petroleumhydrocarbon products increases [11]

e dielectric property of soils which (namely the per-mittivity) controls the penetration depth of microwaves hasbeen well established in the literature [12ndash14] e denepenetration depth as the distance in the medium over whichthe intensity of propagating radiation decreases (owing toattenuation) by a linear pattern because of the small contrastbetween the permittivity of dry soil and diesel oil andbecause the amount of diesel oil in the soil is variablesoil contamination by diesel does not largely control thepermittivity of the soil and thus penetration depth as well

e majority of studies on this subject has been con-cerned with crude oil contamination in the marine envi-ronment which reects the importance of studying oil con-tamination on terrestrial ecosystems by using remote sens-ing techniques Previously multispectral satellite imagerywas used to map contamination by locating the reectivityand absorption spectra of diesel-oil contaminated soil andplotting the corresponding spatial distributions [15 16]Nonetheless some attempts at mapping hydrocarbons usingLandsat and Daedalus in mid-1990s failed probably due tothe limited spectral resolution of the multispectral sensors[17] Moreover the spectral properties of hydrocarbonswere identied at the late 1980s [18] Several studies wereconducted during the past few years in the eld of petroleumhydrocarbons and reectance spectroscopy [19ndash21] thatshowed the potential of reectance spectroscopy as a toolfor predicting total petroleum hydrocarbons content [17]In 1990s the US Department of Energy contracted a pri-vate company to investigate the application of reectancespectroscopy to determine motor oil contamination in sandyloam A schematic design for a eld instrument was sug-gested although only one contaminant and one type of soilwere tested using very few samples with a very limitedrange of contamination [22] More comprehensive studieswere conducted in the last decades using different types ofsoil contaminated in the laboratory with several types ofhydrocarbons [23 24] A recent study by Chakraborty et al[25] on the prediction accuracy of NIR-SIR reectancespectroscopy of petroleum products contaminated soil andshowed fair validation results (1198771198772 = 064) [17]

e results of the aforementioned studies also support theuse of hyperspectral remote sensing for the direct detectionof spills of diesel in different types of soil Hyperspectralairborne remote sensing was also applied to identifying

hydrocarbon contamination e higher spatial and spectralresolution as well as the very high signal-to-noise ratioof the airborne hyperspectral sensor used (HyMap) [26]yielded successful identication of hydrocarbon- and oil-contaminated soils but only for high contaminant con-centrations [19] Nevertheless according to the literaturereview there is shallow radius of investigation in the eld ofmicrowave remote sensing using different types of sensors(ie radars radiometers and scatterometers) for detectingand identifying the extent and the amount of diesel contam-ination in soil

e present study was undertaken to determine the effectof contamination of soil with diesel oil on the permittivityand scattering coefficient of soil In this study laboratoryexperiments were conducted with the aim of studying theelectrical parameters of soil composting with 1 to 22concentrations of diesel oil (mass percentages) to evaluate theresponse of the method in monitoring the electrical param-eters of the compound An attempt was made to providean overview of the microwave remote sensing measurementtechniques used to measure the permittivity of diesel-oilcontaminated soil using waveguide cell with shi in minimamethod and to estimate the backscattering coefficient of soilcontaminated by diesel in C band (53GHz) e rationalebehind this band selection was that the oil spill pollution canbe detected using microwave sensors and one of the usefulfrequencies is the C band [27] Many sensors of differentsatellites such as ERS-1 ERS-2 RADARSAT 1 and 2 andASCAT operate in the C band Microwave remote sensinginstruments equippedwithCband are generally not hinderedby atmospheric effects and are capable of ldquoseeingrdquo throughclouds ese sensors have the capability of monitoring 24hours a day in all weather conditions at a fairly high spatialresolution (few meters)

e backscattering coefficient is calculated using themeasured value of the permittivity for different amountsof diesel contaminations Using slightly rough surfaces andsmall perturbation model the backscattering coefficient wasmeasured for different amounts of diesel contamination andvariable angles of incident from 10∘ to 80∘ e database forthe scattering coefficient was generated for different anglesof incident and for both polarizations e backscatteringcoefficients at different incident angles (25∘ 30∘ 35∘ 40∘45∘ 50∘ and 55∘) were calculated and are useful for com-parison with the data of airborne and space borne remotesensing sensors erefore in view of the current and futureairbornespaceborne remote sensing platforms that are beingdeveloped to obtain data needed to understand the soilsurface characteristics this study supports the use of low-frequency (C-band) bipolarized and multiple-angle activemicrowave observations

2 Methodology

21 Soil Samples Sample Holder and Preparation of SoilSamples e study was conducted in the laboratory Becauseof the labor-intensive nature of enumerations and activitymeasurements this study was conned to a single fuel (diesel

International Journal of Microwave Science and Technology 3

oil) soil type (loamy sand soil) and incubation temperature(25 plusmn 2∘C) is type of soil is chosen because it is a desertsoil having large percentage of sand Sandy soil lacks waterholding capacity as in the case of Rajasthan India Dry soilparticles usually found at the surface in arid regions mightadsorb fuel hydrocarbons to their surfaces thus being coatedor ldquoimpregnatedrdquo against soil moisture [24] Laboratorystudies were done using soil samples obtained at depths of 0to 10 cm To avoid stones and other rough material causingproblems during the mixing process the soils were sievedwith a screen shaker and the samplematerial was placed in anoven e oven temperature was maintained at 120∘C Aerdrying the soil at 120∘C for 10 hours the soil was cooled in adesiccator and reweighed and the dry weight was calculatedSoil moisture was measured by drying at 120∘C to a constantweight All results throughout the paper were calculated perdry weighte different percentages of diesel oil were mixedwith the soil samples Different amounts of diesel fuel wereintroduced into the soil at concentrations of 1 to 22 andthe weight percentage of the compound was measured eachtime e experiment was done at room temperature (25 plusmn2∘C)

e specic properties of the soil samples were themoisture content in percent119882119882 119882 119882119882119882 and the specic gravityof soil grains 119866119866119878119878 119882 21198826 e sample was a loamy-sand soilwith an average texture of 8330 ne sand 340 coarsesand 333 silt and 985 clay with a wilting coefficientof 006 e density of diesel is about 780 to 1074 kgmminus3

with a specic gravity of 94 to 129 kgmminus3 at 25∘C Onceyou mixed the diesel with soil the diesel occupies the poresby replacing air Also when pores are lled a thin layer isformed on the surface and it does not settle below the soiland a sort of contaminated soil with diesel will be createdwhere the molecules of diesel get bound on soil particles andsome molecules of diesel remains free and so there is bothbound diesel and free diesel In this case only the free dieselaffects the dielectric constant of the mixture of diesel andsoil ecause of free and bound molecules of diesel the naldielectric constant will be lower than the lowest because thiscombined results will be always less than the lowest

22 Permittivity e permittivity is one of the most impor-tant parameters for studying the behavior of materials inmicrowave remote sensinge fundamental electrical prop-erties through which the interactions between the electro-magnetic wave and thematerial are describedmathematically

120576120576 119882 120576120576prime minus 119895119895120576120576primeprime (1)

where the real part (120576120576prime) or the strong factor characterizesthe ability of a material to store the electric-eld energy eimaginary part (120576120576primeprime) the dielectric loss factor reects theability of a material to dissipate electric energy in the formof heat

ere are several methods for measuring permittivityPermittivity is one of the most important factors for evalu-ating the physical and chemical properties of the materials

Measurement of permittivity can be done in the laboratory aswell as in the eld using four methods namely the following

(1) transmission linemethod (2) resonant cavitymethod(3) free space method and (119882) waveguide cell methode measurement techniques appropriate for any particularapplication depend upon the dielectric properties of thematerials to be measured the physical state of the materials(solid semisolid or liquid) the frequency range and thedegree of accuracy required [24]

In this paper waveguide cell device is used to measurethe permittivity of diesel oil using shi in minima methodNarrowband waveguide cells require careful sample prepa-ration but they provide accurate permittivity measurementsfor solids particulates and liquids e formula used forcalculation of permittivity can be described as follows

e characteristic impedance1198851198850 of a transmission systemmay be dened as an impedance to have the same value at theother extremity In free air and for a uniform plane wave thischaracteristic impedance is

1198851198850119886119886 119882 1003532100353212058312058301205761205760

120582120582119886119886119891119891 119882 119891119891 1198821

radic12058312058301205761205760

(2)

where 120582120582119886119886 is the wavelength in free air In free space lled witha dielectric material with dielectric constant 120576120576119903119903

1198851198850120576120576 119882 1003532100353212058312058301205761205760120576120576119903119903

1198821198851198850119886119886

radic120576120576119903119903

120582120582120576120576119891119891 119882119891119891radic120576120576119903119903

120582120582119886119886120582120582120576120576

119882 radic120576120576119903119903

(3)

where 120582120582120576120576 is the wavelength in the dielectric material Fromthe above equations

1198851198850119892119892119886119886

1198851198850119892119892120576120576119882120582120582119892119892119886119886120582120582119892119892120576120576

119882 (4)

1198851198850119892119892119886119886 and 1198851198850119892119892120576120576 are the characteristic impedances of the waveguide lled with air and the dielectric material respectively120582120582119892119892119886119886 And 120582120582119892119892120576120576 are the wavelengths in the waveguide lledwith air and the lossless dielectric material respectivelyConsidering a short circuited waveguide which contains asquare cut sample of dielectric material with a physical length119871119871 that touches the short circuit plane one can derive theimpedance 119885119885 for the region of the dielectric nearest to thegenerator

119885119885 119882 1198851198850119892119892120576120576 tan2120587120587120587120587120582120582119892119892120576120576

119882 (5)

When the piece of dielectric material is removed the sameimpedance 119885119885 is measured at a position 119889119889 119889 119871119871 where 119889119889 is the


displacement of the minimum of the standing wave patternwhich is caused by the change in the wavelengthereby onemay write

tan 100765010076502120587120587 (119889119889 119889 119889119889) 120582120582119892119892119892119892100766610076662120587120587119889119889120582120582119892119892119892119892

=tan 100765010076502120587120587119889119889120582120582119892119892119892119892100766610076662120587120587119889119889120582120582119892119892119892119892

(6)

where 119889119889 is thickness of the sample 119889119889 is shi in minima 120582120582119892119892119892119892is guide wavelength in the air-lled wave guide 120582120582119892119892119892119892 is guidewavelength in dielectric-lled wave guide In a rectangularwaveguide system the propagation constant is given by

1205741205742 = 10076521007652119898119898120587120587119887119887100766810076682119889 10076521007652

119899119899120587120587119892119892100766810076682minus 1205961205962119892119892120576120576 (7)

where 120574120574 = 120574120574 119889 120574120574120574120574 in which 120574120574 is the attenuation constantassuming a lossless material (120574120574 = 120572) and with 119898119898 = 120572 120576120576 = 120576120576120572and 119899119899 = 119899 formula (7) will transform into

119892119892119903119903 = 100765310076531205821205821198921198922119892119892100766910076692119889 10076541007654

120582120582119892119892120582120582119892119892119892119892

100767010076702

(8)

where 119892119892 is width of the waveguide 120582120582119892119892 is wavelength in freespace From (6) the value of 120582120582119892119892119892119892 can be extracted substitutingin formula (8) the permittivity can be calculated

Excessive work was done to measure the dielectric per-mittivity of soil contamination by diesel Dielectric permittiv-ity can change with frequency temperature orientation mix-ture pressure and molecular structure of the material eelectrical parameters such as scattering coefficient dependupon the permittivity of thematerial At radio frequencies thevalue of the permittivity of a natural material is related to itsphysical parameter

e source of errors in the waveguide with shi inminima method can be dened as follows (119899) A number ofminima positions are sometimes obtained and then it is amatter of choice to select the correct minima (2) Error isalso introduced in the slotted line section due to backlasherror and improper insertion of the probe which can bereduced by careful handling (3) Error is introduced if thereis nonconsistency in the dimensions of the waveguide usedin the test bench setup and the waveguide cell carrying thesample (4) e weight of the dielectric sample is a veryimportant parameter and inaccuracy in its measurementmaylead to considerable errors So the waveguide with shi inminima method errors is approximately plusmn4 as investigatedin [2]

23 Experimental Setup In the waveguide method the per-mittivity is measured by calculating the shi in minima ofthe standing wave pattern inside a rectangular waveguideis shi occurs due to the change in the guide wavelengthwhen a dielectric material is introduced into the waveguideFigure 1 depicts a block diagram of the experimental setup Inthis setup Gunn power supply comprises of an electronicallyregulated power supply and a squarewave generator designedto operate the Gunn Oscillator and Pin Modulator Anisolator is a two-port device that transmits microwave or

radio frequency power in one direction only It is usedto shield equipment on its input side from the effects ofconditions on its output side for example to prevent amicrowave source being detuned by a mismatched load eoscillator uses a cavity the size of this cavity determines thetimephase delay which sets the resonant frequency In thiscase each diode induced uctuation travels up the cavityand reected from the far end returning to the diode aera time e power of the microwave signal generated bythe Gunn Oscillator can be varied by varying the voltageapplied to this oscillator by the Gunn Power Supply In themicrowave terminology any dissipative element inserted inenergy eld is called an attenuator It consists of a resistiveor ldquolossyrdquo surface sometimes referred to as a ldquocardrdquo placedin the center of a waveguide through a slot On increasingthe penetration of the card it absorbs more energy andthe attenuation therefore increases As the card is movedupwards the attenuation decreases toward the minimume adjustment is done with a micrometer whose positionis related to the attenuation e entire assembly is calleda calibrated variable attenuator e microwave frequencymeter is used for measuring frequency without resorting tothe slotted line quickly and easily Directional couplers areused for sampling a part of microwave energy for monitoringpurposes A microwave power meter is an instrument whichmeasures the electrical power at microwave frequenciesUsually a microwave power meter will consist of a measuringhead which contains the actual power sensing elementconnected via a cable to the meter properly which displaysthe power reading e head may be referred to as a powersensor or mount Different mounts can be used for differentfrequencies or power levels e slotted section is primarilya section of waveguide having dimensions suitable for thefrequency range in use ldquoVSWRrdquo stands for ldquovoltage standingwave ratiordquo It is an RF (radio frequency) signal source VSWRmeter is used for measuring voltage standing wave ratioattenuation and total mismatch on the line

A brief description of the procedure can be explained asfollows Build up the measuring setup shown in Figure 1Turn on the gun power supply Adjust the gun power supplyin order to get maximum output power To do this set theprobe of the voltage standing wave meter in a maximumposition Find at least three successive minima 119909119909119892119892 119909119909

prime119892119892 119909119909

primeprime119892119892

by using the calibrated attenuator at minimum attenuationIntroduce the dielectric sample and determine again atleast three successive minima 119909119909119892119892 119909119909

prime119892119892 119909119909

primeprime119892119892 For calculating the

displacement either the average of the shis or the shivalue which occur maximum number of times can be takenalculate the rst term of (6) when (119889119889) is positive theminima is shied towards the load so (119889119889) determines thesign for tan 119909119909119909119909 Look up in the tan 119909119909119909119909 table and thevarious values which 2120587120587(119889119889 119889 120587120587)120582120582119892119892119892119892 can have and thus ndvalues of 120582120582119892119892119892119892 and 119892119892119903119903 in accordance with (8) To nd thecorrect value of 119892119892119903119903 the measurement should be repeated witha sample of a different length and the common value of thetwo series should be taken When the order of magnitude ofthe dielectric permittivity is known the measurement with adifferent length is not necessary


Isolator Attenuator Frequency

meterSlotted section

Directional couplerGunn

oscillator

VSWR meter

Power meter

Gunn power supply

Wave guide cell

F 1 Block diagram of experimental setup

3 Scattering Coefficient

When an electromagnetic wave is incident on the boundarysurface between two seminite media a portion of theincident energy is scattered backwards with the remaindertransmitted into the second medium In special cases wherethe lower medium is homogenous the phenomenon ofscattering is called surface scattering If the lower medium isinhomogeneous scattering takes place from within the vol-ume of the lower medium which is called volume scatteringe surface pattern plays an important role in estimating thescattering coefficient A surfacemay appear very rough for anoptical wave but the same surface may appear very smoothto a microwave signale two important parameters used tocharacterize surface roughness are the standard deviation ofthe surface height variation (120590120590 rms height) and the surfacecorrelation length (119897119897) in terms of wavelength As the surfacecorrelation length increases the surface becomes smootherand the radiation pattern becomes more directional

Ulaby et al [28] suggested that depending on the surfacepattern three different models are used to estimate thescattering coefficient the perturbation model the physicaloptics model and the geometric optics model Using a modelto estimate the scattering coefficient depends on surfaceroughness e scattering coefficient of the materials can beobtained in two ways directly by measuring the scatteringcoefficient of the material using a scatterometer or radar orby measuring the dielectric permittivity and using availablemodels e perturbation physical optics and geometricoptics models are used for slightly rough medium roughand undulating surfaces respectively It is also necessaryto note that on a homogeneous soil with perfectly smoothsurface scattering of electromagnetic waves is totally forwardand depends on permittivity of the medium Selecting acomputation model for a particular surface will depend onthe validity of that model for the surface under investigation

e perturbation model is appropriate for slightly roughsurfaces where both the surface standard deviation andcorrelation length are smaller than the wavelength estandard deviation should be at least 5 less than that ofthe electromagnetic wavelength and the slope of the surfaceshould be of the same order ofmagnitude as thewave numbertimes the surface standard deviation is relationship isrepresented mathematically as follows

119870119870120590120590 119870 119870119870119870119870 119870119870 119870 119870119870119870119870 (9)

where 119870119870 119870 119870119870119870119870119870119870 119870119870 119870 1198721198701198721119870119870120590120590119870119897119897 is surface slop (rms) 120590120590= rms surface height and 119897119897 is correlation length erebyfor estimation of backscattering coefficient the validationcondition can be considered

119870119870120590120590 119870 119870119870119870119870119870 119870119870 119870 119870119870119870119870119870 (10)

e backscattering coefficient is given by

120590120590119870119901119901119901119901119901119901 119872120579120579119872 119870 81198961198964120590120590119870cos41205791205791009250100925012057212057211990111990111990111990112057912057910092501009250

119870119882119882 119872119870119896119896 s119896119896 120579120579119872 119870 (11)

where 119901119901 is polarization 119907119907 is vertical polarization ℎ ishorizontal polarization and |120572120572119901119901119901119901119872120579120579119872|

119870 119870 Γ119901119901119872120579120579119872 is the Fresnelreection coefficient e value for the Fresnel reectioncoefficient under horizontal polarization is obtained by

120572120572ℎℎ 119872120579120579119872 119870cos 120579120579 120579 10076501007650120576120576119904119904 120579 sin11987012057912057910076661007666

1119870119870

cos 120579120579 120579 10076491007649120576120576119904119904 120579 sin119870120579120579100766510076651119870119870119870 (12)

For vertical polarization the Fresnel coefficient 120590120590119907119907119907119907 isobtained by

120572120572119907119907119907119907 119872120579120579119872 119870 10076491007649120576120576119904119904 120579 110076651007665sin119870120579120579 120579 120576120576119904119904 100765010076501 120579 119870sin

11987012057912057910076661007666

10077151007715120576120576119904119904 cos 120579120579 120579 10076491007649120576120576119904119904 120579 sin11987012057912057910076651007665111987011987010077311007731119870 119870 (13)

where 120576120576119904119904 is the dielectric permittivity of the emitter and120579120579 is the angle of incidence 119882119882(119870119896119896 s119896119896 120579120579) is the normalizedroughness spectrum which is the Bessel transform of thecorrelation function 120588120588119872120588120588119872 evaluated at the surface wavenumber of 119870119870119870 s119896119896 120579120579 For the Gaussian correlation function120588120588119872120588120588119872 119870 expo119872120579120588120588119870119870119897119897119870119872 the normalized roughness is given by

119882119882119872119870119896119896 s119896119896 120579120579119872 1198701119870119897119897119870expo 10077141007714120579119872119896119896119897119897 s119896119896 12057912057911987211987010077301007730 119870 (14)

Estimation of the scattering coefficient of diesel oil-contaminated soil for a slightly rough surface was donein the C band (53GHz) for different look angles in 5-degree intervals ranging from 10 to 80 degrees and for twopolarizations is model is used for the research becausein natural conditions the soil surface roughness normallyobserved ts into the small perturbation model that has beenchosen for this paper Moreover since this study is relevantto the back scatter 120590120590∘ and 120590120590∘ depends upon 120576120576prime not 120576120576primeprime e 120576120576primeprimewhich is loss factor has no signicance


4 Results and Discussion

Measurements of diesel oil-contaminated soil were per-formed on different dried soil samples We will present someresults obtained using the created application e dielectricpermittivity and scattering coefficient of the compoundwere calculated e measurements were made in C band(53GHz) for different amounts of diesel oil contamination atdifferent incident angles for the both horizontal and verticalpolarizations e saturation point was observed aer theintroduction of 22 of diesel oil to soil At this weightpercentage of diesel the dielectric constant of the compoundis close to the dielectric constant of diesel Aer this specicpercentage of diesel in soil the amount of change in thedielectric constant of compound is negligible is may bedue to the fact that as diesel oil and other renery productsthat penetrate deep into soil block air spaces that allow airand water to enter soil layers As a result the soil becomesmore compact its physical chemical and biological prop-erties alter nally its characteristics become more similarto characteristics of diesel oil and consequently cause thechanges in the its dielectric permittivity and backscatteringcoefficient Finally based on the physicochemical propertiesof soils and diesel the spectral response of soils and dieselas single components and the distribution pattern andenvironmental behavior of fuel hydrocarbons (eg diesel) ascontaminants in soils it is anticipated that both uncontami-nated soil and soil contaminated with diesel that are exposedat the surface are relatively homogeneous media over largerareas

Figure 2 represents the dielectric permittivity of soildiesel and diesel-oil contaminated soil for different weightpercentages from 1 to 22 e errors explained in mea-surement method (plusmn4) are introduced in the graph (errorbars) e amount of change in dielectric constant for thediesel-oil contaminated soil is around 73 for a 1 changein the weight of diesel in soil

e scattering coefficient was estimated for different lookangles varying by 5-degree intervals from 10 to 80 degreesand for both vertical and horizontal polarization Figure 3shows the variation of the scattering coefficient of soil withdifferent weight percentages of diesel with respect to lookangles ranging from 10 to 80 degrees for a slightly roughsurface and for both horizontal and vertical polarization ata xed frequency 53GHz From the gure it is observed thatthe scattering coefficient for slightly rough surface decreasesas the look angle increases for horizontal polarization edifference in scattering coefficient between HH and VVpolarization increases as the look angle increases for eachof the weight percentages of diesel-oil contaminated soile values of the scattering coefficient for VV polariza-tion are higher than the values for HH polarization escattering coefficient for vertical polarization is higher thanfor horizontal polarization Vertical polarization for bothtransmission and reception (VV) yields better results for thescattering coefficient than the HH conguration Moreoverthe real part of the dielectric permittivity ranges from 388 fordry soil to about 235 for diesel oil-contaminated soil isvariation can result in a change on the order of 38 dB in the

2

25

3

35

4

45

0 2 4 6 8 10 12 14 16 18 20 22

Diesel oil

Soil

Die

lect

ric

per

mit

tivi

ty

Diesel oil-contaminated soil

Percentage

F 2 Dielectric constant of diesel oil soil and diesel oil-contaminated soil

10 20 30 40 50 60 70 80

Sca

tter

ing

coeffi

cien

t

2()HH

2()VV14()HH

14()VV

21()HH

21()VV

minus10

minus15

minus20

minus25

minus30

minus35

minus40

minus45

minus50

Degree

F 3 Variation of scattering coefficient with respect to thedifferent look angles for 2 14 and 21 diesel in soil

magnitude of the backscattering coefficient for both HH andVV polarization at 10-degree incidence angle and 0843 dBin themagnitude of the backscattering coefficient for HH andVV polarization respectively at 80-degree incidence angle

Figure 4 represents the scattering coefficient at differentspecial angles that are desirable for remote sensing sensorse results of the experiment for scattering showed that thereis a slight decline in the scattering coefficient as the weightpercentage of diesel increases during the process Figure 4demonstrates that the scattering coefficient decreases as thecombination of soil and diesel increases in both horizontaland vertical polarization e scattering coefficient valuesfor vertical polarization are more than those for horizontalpolarizatione scattering coefficient pattern for these threespecic angles followed a typical linear equation


T 1 Equations and correlation coefficient of variation of scattering coefficient for different look angles and dielectric constant of dieseloil-contaminated soil from 1 to 22

Equation Correlation coefficient (1198771198772)25 (HH) 119910119910 119910 119910119910119910119910119910119910119910119910119910 119910 119910119910119910119910119910119910 0959225 (VV) 119910119910 119910 119910119910119910119910119910119910119910119910119910 119910 1199101199101199101199101199102 0960730 (HH) 119910119910 119910 119910119910119910119910119910119910119910119910119910 119910 1199101199101199101199102 0958830 (VV) 119910119910 119910 1199101199101199101199101199102119910119910119910 119910 1199101199101199101199101199102 096135 (HH) 119910119910 119910 119910119910119910119910119910119910119910 119910 119910119910119910119910119910119910 0958435 (VV) 119910119910 119910 119910119910119910119910119910119910119910119910 119910 1199102119910119910119910119910 0961540 (HH) 119910119910 119910 1199101199101199101199101199102119910119910119910 119910 119910119910119910119910119910119910 095840 (VV) 119910119910 119910 119910119910119910119910119910119910119910119910119910 119910 11991021199101199101199102 096245 (HH) 119910119910 119910 119910119910119910119910119910119910119910119910119910 119910 2119910119910119910119910119910 0957445 (VV) 119910119910 119910 119910119910119910119910119910119910119910119910119910 119910 1199102119910119910119910119910 0962750 (HH) 119910119910 119910 1199101199101199101199102119910119910119910119910 119910 2119910119910119910119910119910 0956950 (VV) 119910119910 119910 119910119910119910119910119910119910119910119910119910 119910 1199101199101199101199102119910 0963655 (HH) 119910119910 119910 1199101199101199101199101199102119910119910119910 119910 2119910119910119910119910119910 0956355 (VV) 119910119910 119910 1199101199101199101199101199101199102119910119910 119910 119910119910119910119910119910119910 09646Dielectric permittivity 119905119905 of diesel oil contaminated soil 119910119910 119910 1199101199101199101199101199102119910119910119910 119910 1199101199101199101199102119910 09928

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22

Sca

tter

ing

coeffi

cien

t

Diesel weight ()

25(HH)

25(VV)

30(HH)

30(VV)

35(HH)

35(VV)

40(HH)

40(VV)

45(HH)

45(VV)

50(HH)

50(VV)

55(HH)

55(VV)

minus12

minus14

minus16

minus18

minus20

minus22

minus24

minus26

minus28

F 4 Variation of scattering coefficient in respect to differentweight percentages of diesel in soil for different look angles

Table 1 shows the equations and correlation coefficientof variation of scattering coefficient for different look anglesfrom and the dielectric permittivity of diesel-oil contam-inated soil from 1 to 22 Weight percentage of dieselin soil can be used to measure the dielectric permittivityof diesel-oil contaminated soil in the laboratory or in theeld and vice versa if the dielectric permittivity of diesel-oil contaminated soil is known then it is possible to estimatethe weight percentage of diesel in soil As it is observed fromTable 1 for estimating the values of scattering coefficient ofdiesel-oil contaminated soil there is no need for calculatingthe dielectric permittivity and with substituting the weightpercentage value of diesel in soil by 119910119910 in the corresponding

equation the values of scattering coefficient are obtainableOn the other hand for known values of scattering coeffi-cient which are derived from the satellite data the weightpercentage of diesel in soil can be calculated easily from theequations Also it is possible to nd the dielectric permittivityand scattering coefficient values for all the weight percentageswhich are not mentioned here

Terrestrial oil spills are characterized primarily by verticalmovement of the oil into the soil rather than by the hori-zontal spreading associated with slick formation [9] Furtherstudies are required to elucidate diesel oil-contaminatedsoil conditions in different microwave bands such as XS and L band to illuminate the penetration capabilitiesof the wave in cases of soil pollution On the other handfurther research is necessary to study the passive microwaveremote sensing of diesel oil-contaminated soil in differentmicrowave bands Due to the health and environmental risksassociated with the loss of volatile compounds compostingof hydrocarbons especially gasoline-contaminated soil in vasteld experiments is not recommended Moreover furtherinvestigation is necessary to study the effect of reneryproducts for example diesel oil on different types of soil byremote sensing techniques Furthermore additional studiesare necessary to identify the functions of the imagery partof the dielectric permittivity and its effects on emission andscattering of the compound At the end it is worth notingthat for anymicrowave imaging and nonimaging applicationsaimed at the detection of fuel hydrocarbon contaminated soilit should be taken into account that areas of contaminatedsoil have been covered with uncontaminated material dueto natural erosion and deposition processes Due to thisfact microwave remote sensing sensors are highly applicablebecause of their penetration capability Moreover recom-mendations for required resolutions (spatial temporal etc)for the application of microwave imaging for detection andinvestigation of contamination of soil with fuel hydrocarbonneed to be derived based on scattering properties and spatial


distribution of the target being observed Furthermore incase of diesel or similar fuel(s) dark coloring indicates heavydiesel fuel contamination on the soil (eg in surrounding ofthe petrol pump or reneries on an area of approximatelyten(s) of meters) So synergy of microwave remote sensingwith imaging spectrometry or any other remote sensing tech-niques might be used to locate the contaminated site(s) andthe extent of it very accurately At the end it is worth men-tioning that a comprehensive study including several types ofsoil with several types of petroleum hydrocarbons at a largevariety of contamination levels has not yet been publishedMost of the studies were performedwith laboratory-preparedsamples and almost none collected in the eld Furthermoreno generic models were developed and no quantitativemodels were tested although this was mentioned as anavenue of further study [24] especially combining laboratoryand eld samples and no real quantitative operation modelwas presented for real-life applications

5 Summary and Conclusions

e dielectric permittivity of oil has a direct effect onscatterometer and radar sensors mounted on ground basedairborne and spaceborne platforms A good understandingof the electrical properties of oil is vital to extract use-full information from the remotely sensed data for earthresources monitoring and management Prompted by theneed to measure the microwave dielectric permittivity of oila practical technique suitable for measuring the dielectricconstant is sought

In this paper the dielectric constant is measured usingwaveguide with shi in minima method the scatteringcoefficient of soil contaminated by diesel was measured at53GHz in the C band using perturbation

From the results presented in this paper it is possible todetermine the values scattering coefficient for known weightpercentage of diesel in soil directly without measuring thedielectric permittivity and on the other hand for knownvalueof scattering coefficient we can estimate the value of weightpercentage of diesel in soil

References

[1] X Jinkai ldquoDielectric properties of minerals and their appli-cations in microwave remote sensingrdquo Chinese Journal ofGeochemistry vol 9 no 2 pp 169ndash177 1990

[2] O P N Calla M Mathur M Upadhayay R Punia and PChaudhary ldquoImage generation for microwave remote sensingusing java languagerdquo in Proceedings of the 1st InternationalConference on Microwave Antenna Propagation and RemoteSensing (ICMARS rsquo03) pp 3ndash8 Jodhpur India December 2003

[3] O P N Calla D Bohra N Ahmadian S Hasan and RVyas ldquoStudy of effect on the electrical parameters of soil inpresence of diesel oil at C band (53GHZ)rdquo in Proceedings ofthe National Conference on Emerging Trends in Electronic andTelecommunication India Vision 2020 pp 139ndash142 JodhpurIndia March 2009

[4] National Academy of Sciences Oil in the Sea-Inputs Fates andEffects National Academy Press Washington DC USA 2002

[5] WMichalcewicz ldquoWpływ oleju napccedildowego do silnikoacutewDieslana liczebność bakterii grzyboacutew promieniowcoacutew oraz biomasccedilmikroorganizmoacutew glebowychrdquo Roczniki Pantswowego ZakladuHigieny vol 46 pp 91ndash97 1995

[6] H G Song and R Bartha ldquoEffects of jet fuel spills on themicrobial community of soilrdquo Applied and EnvironmentalMicrobiology vol 56 no 3 pp 646ndash651 1990

[7] A Amadi S D Abbey and A Nma ldquoChronic effects of oil spillon soil properties and microora of a rainforest ecosystem inNigeriardquoWater Air and Soil Pollution vol 86 no 1ndash4 pp 1ndash111996

[8] K S Joslashrgensen J Puustinen and A M Suortti ldquoBiore-mediation of petroleum hydrocarbon-contaminated soil bycomposting in biopilesrdquo Environmental Pollution vol 107 no2 pp 245ndash254 2000

[9] J G Leahy and R R Colwell ldquoMicrobial degradation ofhydrocarbons in the environmentrdquoMicrobiology andMolecularBiology Reviews vol 54 no 3 pp 305ndash315 1990

[10] A Husaini H A Roslan K S Y Hii and C H Ang ldquoBiodegra-dation of aliphatic hydrocarbon by indigenous fungi isolatedfrom used motor oil contaminated sitesrdquo World Journal ofMicrobiology and Biotechnology vol 24 no 12 pp 2789ndash27972008

[11] P O Abioye A Abdul Aziz and P Agamuthu ldquoEnhancedbiodegradation of used engine oil in soil amended with organicwastesrdquo Water Air and Soil Pollution vol 209 no 1ndash4 pp173ndash179 2010

[12] E G Njoku and J A Kong ldquoeory for passive microwaveremote sensing of near-surface soil moisturerdquo Journal of Geo-physical Research vol 82 no 20 pp 3108ndash3118 1977

[13] E G Njoku and D Entekhabi ldquoPassive microwave remotesensing of soil moisturerdquo Journal of Hydrology vol 184 no 1-2pp 101ndash129 1996

[14] F T Ulaby R K Moore and A K Fung Microwave RemoteSensing Active and Passive Vol III Volume Scattering andEmission eory Advanced Systems and Applications ArtechHouse Dedham Mass USA 1986

[15] MK Blade and H D Ziervogel ldquoe use of remote sensingtechnology to delineate hydrocarbon contamination in theArcticrdquo Published in EBA Special Edition 2011

[16] O V Toutoubalina and W G Rees ldquoRemote sensing of indus-trial impact on Arctic vegetation around Norilrsquosk northernSiberia preliminary resultsrdquo International Journal of RemoteSensing vol 20 no 15-16 pp 2979ndash2990 1999

[17] G Schwartz G Eshel M Ben-Haim and E Ben-DorReectance Spectroscopy as a Rapid Tool for ualitativeMappingand Classication of Hydrocarbons Soil Contamination Tel AvivIsrael 2009

[18] E A Cloutis ldquoSpectral reectance properties of hydrocarbonsremote-sensing implicationsrdquo Science vol 245 no 4914 pp165ndash168 1989

[19] B Houmlrig F Kuumlhn F Oschuumltz and F Lehmann ldquoHyMap hyper-spectral remote sensing to detect hydrocarbonsrdquo InternationalJournal of Remote Sensing vol 22 no 8 pp 1413ndash1422 2001

[20] T Lammoglia and C R D S Filho ldquoSpectroscopic character-ization of oils yielded from Brazilian offshore basins potentialapplications of remote sensingrdquoRemote Sensing of Environmentvol 115 no 10 pp 2525ndash2535 2011

[21] G Schwartz E Ben-Dor and G Gil Eshel ldquoQuantitativeanalysis of total petroleum hydrocarbons in soils comparisonbetween reectance spectroscopy and solvent extraction by 3


certied laboratoriesrdquo Applied and Environmental Soil Sciencevol 2012 Article ID 751956 11 pages 2012

[22] B R Stallard M J arcia and S Kaushik ldquoNear-IR reectancespectroscopy for the determination of motor oil contaminationin sandy loamrdquoApplied Spectroscopy vol 50 no 3 pp 334ndash3381996

[23] H W Zwanziger and H Foumlrster ldquoNear infrared spectroscopyof fuel contaminated sand and soil I preliminary results andcalibration studyrdquo Journal of Near Infrared Spectroscopy vol 6no 1ndash4 pp 189ndash197 1998

[24] K HWinkelmannOn the applicability of imaging spectrometryfor the detection and investigation of contaminated sites with par-ticular consideration given to the detection of fuel hydrocarboncontaminants in soil [PhD thesis] Brandenburg University ofTechnology at Cottbus 2005

[25] S Chakraborty D C Weindorf C L S Morgan et al ldquoRapididentication of oil-contaminated soils using visible near-infrared diuse reectance spectroscopyrdquo Journal of Environ-mental Quality vol 39 no 4 pp 1378ndash1387 2010

[26] T Cocks ldquoe HyMapTM airborne hyperspectral sensor thesystem calibration and performancerdquo in Proceedings of the 1stEARSeLWorkshop on Imaging Spectroscopy pp 37ndash42 EARSeL1998

[27] D W Charles ldquoSummary of space-based active and passivesensor applications for disasterrdquo in Proceedings of the 3th NOAASupport Passive Sensing Microwave Workshop Silver SpringMD USA May 2007

[28] F T Ulaby R K Moore and A K Fung Microwave RemoteSensing Active and Passive Vol II Radar Remote Sensing and Sur-face Scattering and Emission eory Addison-Wesley ReadingMass USA 1982

International Journal of

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Active and Passive Electronic Components

Control Scienceand Engineering

Journal of



RotatingMachinery


Hindawi Publishing Corporation httpwwwhindawicom

Journal ofEngineeringVolume 2014

Submit your manuscripts athttpwwwhindawicom

VLSI Design



Shock and Vibration


Civil EngineeringAdvances in

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Journal of

Advances inOptoElectronics


Volume 2014

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

SensorsJournal of


Modelling amp Simulation in EngineeringHindawi Publishing Corporation httpwwwhindawicom Volume 2014


Chemical EngineeringInternational Journal of Antennas and

Propagation




Navigation and Observation



DistributedSensor Networks



Petrol stations garages that service cars and tractors andseaport are the major locations where soil is polluted byrenery products [5] Other areas of concern are miningand distribution of petroleum-based products [6ndash8] Heavyuse of machinery in agriculture leads to high consumptionof diesel oil Negligence while transporting collecting orstoring renery products together with unsatisfactory carewhile the disposing of old or used petroleum products leadto considerable pollution of the natural environment [9]Spillage of used motor oils such as diesels or jet fuels con-taminates our natural environment with hydrocarbons [10]Soil contamination with diesel and engine oils is becominga major environmental problem as the usage of petroleumhydrocarbon products increases [11]

e dielectric property of soils which (namely the per-mittivity) controls the penetration depth of microwaves hasbeen well established in the literature [12ndash14] e denepenetration depth as the distance in the medium over whichthe intensity of propagating radiation decreases (owing toattenuation) by a linear pattern because of the small contrastbetween the permittivity of dry soil and diesel oil andbecause the amount of diesel oil in the soil is variablesoil contamination by diesel does not largely control thepermittivity of the soil and thus penetration depth as well

e majority of studies on this subject has been con-cerned with crude oil contamination in the marine envi-ronment which reects the importance of studying oil con-tamination on terrestrial ecosystems by using remote sens-ing techniques Previously multispectral satellite imagerywas used to map contamination by locating the reectivityand absorption spectra of diesel-oil contaminated soil andplotting the corresponding spatial distributions [15 16]Nonetheless some attempts at mapping hydrocarbons usingLandsat and Daedalus in mid-1990s failed probably due tothe limited spectral resolution of the multispectral sensors[17] Moreover the spectral properties of hydrocarbonswere identied at the late 1980s [18] Several studies wereconducted during the past few years in the eld of petroleumhydrocarbons and reectance spectroscopy [19ndash21] thatshowed the potential of reectance spectroscopy as a toolfor predicting total petroleum hydrocarbons content [17]In 1990s the US Department of Energy contracted a pri-vate company to investigate the application of reectancespectroscopy to determine motor oil contamination in sandyloam A schematic design for a eld instrument was sug-gested although only one contaminant and one type of soilwere tested using very few samples with a very limitedrange of contamination [22] More comprehensive studieswere conducted in the last decades using different types ofsoil contaminated in the laboratory with several types ofhydrocarbons [23 24] A recent study by Chakraborty et al[25] on the prediction accuracy of NIR-SIR reectancespectroscopy of petroleum products contaminated soil andshowed fair validation results (1198771198772 = 064) [17]

e results of the aforementioned studies also support theuse of hyperspectral remote sensing for the direct detectionof spills of diesel in different types of soil Hyperspectralairborne remote sensing was also applied to identifying

hydrocarbon contamination e higher spatial and spectralresolution as well as the very high signal-to-noise ratioof the airborne hyperspectral sensor used (HyMap) [26]yielded successful identication of hydrocarbon- and oil-contaminated soils but only for high contaminant con-centrations [19] Nevertheless according to the literaturereview there is shallow radius of investigation in the eld ofmicrowave remote sensing using different types of sensors(ie radars radiometers and scatterometers) for detectingand identifying the extent and the amount of diesel contam-ination in soil

e present study was undertaken to determine the effectof contamination of soil with diesel oil on the permittivityand scattering coefficient of soil In this study laboratoryexperiments were conducted with the aim of studying theelectrical parameters of soil composting with 1 to 22concentrations of diesel oil (mass percentages) to evaluate theresponse of the method in monitoring the electrical param-eters of the compound An attempt was made to providean overview of the microwave remote sensing measurementtechniques used to measure the permittivity of diesel-oilcontaminated soil using waveguide cell with shi in minimamethod and to estimate the backscattering coefficient of soilcontaminated by diesel in C band (53GHz) e rationalebehind this band selection was that the oil spill pollution canbe detected using microwave sensors and one of the usefulfrequencies is the C band [27] Many sensors of differentsatellites such as ERS-1 ERS-2 RADARSAT 1 and 2 andASCAT operate in the C band Microwave remote sensinginstruments equippedwithCband are generally not hinderedby atmospheric effects and are capable of ldquoseeingrdquo throughclouds ese sensors have the capability of monitoring 24hours a day in all weather conditions at a fairly high spatialresolution (few meters)

e backscattering coefficient is calculated using themeasured value of the permittivity for different amountsof diesel contaminations Using slightly rough surfaces andsmall perturbation model the backscattering coefficient wasmeasured for different amounts of diesel contamination andvariable angles of incident from 10∘ to 80∘ e database forthe scattering coefficient was generated for different anglesof incident and for both polarizations e backscatteringcoefficients at different incident angles (25∘ 30∘ 35∘ 40∘45∘ 50∘ and 55∘) were calculated and are useful for com-parison with the data of airborne and space borne remotesensing sensors erefore in view of the current and futureairbornespaceborne remote sensing platforms that are beingdeveloped to obtain data needed to understand the soilsurface characteristics this study supports the use of low-frequency (C-band) bipolarized and multiple-angle activemicrowave observations

2 Methodology

21 Soil Samples Sample Holder and Preparation of SoilSamples e study was conducted in the laboratory Becauseof the labor-intensive nature of enumerations and activitymeasurements this study was conned to a single fuel (diesel













1198851198850119886119886 119882 1003532100353212058312058301205761205760

120582120582119886119886119891119891 119882 119891119891 1198821

radic12058312058301205761205760

(2)


1198851198850120576120576 119882 1003532100353212058312058301205761205760120576120576119903119903

1198821198851198850119886119886

radic120576120576119903119903

120582120582120576120576119891119891 119882119891119891radic120576120576119903119903

120582120582119886119886120582120582120576120576

119882 radic120576120576119903119903

(3)


1198851198850119892119892119886119886

1198851198850119892119892120576120576119882120582120582119892119892119886119886120582120582119892119892120576120576

119882 (4)


119885119885 119882 1198851198850119892119892120576120576 tan2120587120587120587120587120582120582119892119892120576120576

119882 (5)




tan 100765010076502120587120587 (119889119889 119889 119889119889) 120582120582119892119892119892119892100766610076662120587120587119889119889120582120582119892119892119892119892

=tan 100765010076502120587120587119889119889120582120582119892119892119892119892100766610076662120587120587119889119889120582120582119892119892119892119892

(6)


1205741205742 = 10076521007652119898119898120587120587119887119887100766810076682119889 10076521007652

119899119899120587120587119892119892100766810076682minus 1205961205962119892119892120576120576 (7)


119892119892119903119903 = 100765310076531205821205821198921198922119892119892100766910076692119889 10076541007654

120582120582119892119892120582120582119892119892119892119892

100767010076702

(8)







prime119892119892 119909119909



prime119892119892 119909119909







oscillator

VSWR meter

Power meter

Gunn power supply

Wave guide cell






119870119870120590120590 119870 119870119870119870119870 119870119870 119870 119870119870119870119870 (9)


119870119870120590120590 119870 119870119870119870119870119870 119870119870 119870 119870119870119870119870119870 (10)


120590120590119870119901119901119901119901119901119901 119872120579120579119872 119870 81198961198964120590120590119870cos41205791205791009250100925012057212057211990111990111990111990112057912057910092501009250

119870119882119882 119872119870119896119896 s119896119896 120579120579119872 119870 (11)



120572120572ℎℎ 119872120579120579119872 119870cos 120579120579 120579 10076501007650120576120576119904119904 120579 sin11987012057912057910076661007666

1119870119870

cos 120579120579 120579 10076491007649120576120576119904119904 120579 sin119870120579120579100766510076651119870119870119870 (12)


120572120572119907119907119907119907 119872120579120579119872 119870 10076491007649120576120576119904119904 120579 110076651007665sin119870120579120579 120579 120576120576119904119904 100765010076501 120579 119870sin

11987012057912057910076661007666

10077151007715120576120576119904119904 cos 120579120579 120579 10076491007649120576120576119904119904 120579 sin11987012057912057910076651007665111987011987010077311007731119870 119870 (13)


119882119882119872119870119896119896 s119896119896 120579120579119872 1198701119870119897119897119870expo 10077141007714120579119872119896119896119897119897 s119896119896 12057912057911987211987010077301007730 119870 (14)







2

25

3

35

4

45

0 2 4 6 8 10 12 14 16 18 20 22

Diesel oil

Soil

Die

lect

ric

per

mit

tivi

ty


Percentage


10 20 30 40 50 60 70 80

Sca

tter

ing

coeffi

cien

t

2()HH

2()VV14()HH

14()VV

21()HH

21()VV

minus10

minus15

minus20

minus25

minus30

minus35

minus40

minus45

minus50

Degree







1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22

Sca

tter

ing

coeffi

cien

t

Diesel weight ()

25(HH)

25(VV)

30(HH)

30(VV)

35(HH)

35(VV)

40(HH)

40(VV)

45(HH)

45(VV)

50(HH)

50(VV)

55(HH)

55(VV)

minus12

minus14

minus16

minus18

minus20

minus22

minus24

minus26

minus28











References

































RoboticsJournal of





Journal of



RotatingMachinery





VLSI Design



Shock and Vibration







Journal of



Volume 2014


SensorsJournal of





Propagation





















1198851198850119886119886 119882 1003532100353212058312058301205761205760

120582120582119886119886119891119891 119882 119891119891 1198821

radic12058312058301205761205760

(2)


1198851198850120576120576 119882 1003532100353212058312058301205761205760120576120576119903119903

1198821198851198850119886119886

radic120576120576119903119903

120582120582120576120576119891119891 119882119891119891radic120576120576119903119903

120582120582119886119886120582120582120576120576

119882 radic120576120576119903119903

(3)


1198851198850119892119892119886119886

1198851198850119892119892120576120576119882120582120582119892119892119886119886120582120582119892119892120576120576

119882 (4)


119885119885 119882 1198851198850119892119892120576120576 tan2120587120587120587120587120582120582119892119892120576120576

119882 (5)




tan 100765010076502120587120587 (119889119889 119889 119889119889) 120582120582119892119892119892119892100766610076662120587120587119889119889120582120582119892119892119892119892

=tan 100765010076502120587120587119889119889120582120582119892119892119892119892100766610076662120587120587119889119889120582120582119892119892119892119892

(6)


1205741205742 = 10076521007652119898119898120587120587119887119887100766810076682119889 10076521007652

119899119899120587120587119892119892100766810076682minus 1205961205962119892119892120576120576 (7)


119892119892119903119903 = 100765310076531205821205821198921198922119892119892100766910076692119889 10076541007654

120582120582119892119892120582120582119892119892119892119892

100767010076702

(8)







prime119892119892 119909119909



prime119892119892 119909119909







oscillator

VSWR meter

Power meter

Gunn power supply

Wave guide cell






119870119870120590120590 119870 119870119870119870119870 119870119870 119870 119870119870119870119870 (9)


119870119870120590120590 119870 119870119870119870119870119870 119870119870 119870 119870119870119870119870119870 (10)


120590120590119870119901119901119901119901119901119901 119872120579120579119872 119870 81198961198964120590120590119870cos41205791205791009250100925012057212057211990111990111990111990112057912057910092501009250

119870119882119882 119872119870119896119896 s119896119896 120579120579119872 119870 (11)



120572120572ℎℎ 119872120579120579119872 119870cos 120579120579 120579 10076501007650120576120576119904119904 120579 sin11987012057912057910076661007666

1119870119870

cos 120579120579 120579 10076491007649120576120576119904119904 120579 sin119870120579120579100766510076651119870119870119870 (12)


120572120572119907119907119907119907 119872120579120579119872 119870 10076491007649120576120576119904119904 120579 110076651007665sin119870120579120579 120579 120576120576119904119904 100765010076501 120579 119870sin

11987012057912057910076661007666

10077151007715120576120576119904119904 cos 120579120579 120579 10076491007649120576120576119904119904 120579 sin11987012057912057910076651007665111987011987010077311007731119870 119870 (13)


119882119882119872119870119896119896 s119896119896 120579120579119872 1198701119870119897119897119870expo 10077141007714120579119872119896119896119897119897 s119896119896 12057912057911987211987010077301007730 119870 (14)







2

25

3

35

4

45

0 2 4 6 8 10 12 14 16 18 20 22

Diesel oil

Soil

Die

lect

ric

per

mit

tivi

ty


Percentage


10 20 30 40 50 60 70 80

Sca

tter

ing

coeffi

cien

t

2()HH

2()VV14()HH

14()VV

21()HH

21()VV

minus10

minus15

minus20

minus25

minus30

minus35

minus40

minus45

minus50

Degree







1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22

Sca

tter

ing

coeffi

cien

t

Diesel weight ()

25(HH)

25(VV)

30(HH)

30(VV)

35(HH)

35(VV)

40(HH)

40(VV)

45(HH)

45(VV)

50(HH)

50(VV)

55(HH)

55(VV)

minus12

minus14

minus16

minus18

minus20

minus22

minus24

minus26

minus28











References

































RoboticsJournal of





Journal of



RotatingMachinery





VLSI Design



Shock and Vibration







Journal of



Volume 2014


SensorsJournal of





Propagation











tan 100765010076502120587120587 (119889119889 119889 119889119889) 120582120582119892119892119892119892100766610076662120587120587119889119889120582120582119892119892119892119892

=tan 100765010076502120587120587119889119889120582120582119892119892119892119892100766610076662120587120587119889119889120582120582119892119892119892119892

(6)


1205741205742 = 10076521007652119898119898120587120587119887119887100766810076682119889 10076521007652

119899119899120587120587119892119892100766810076682minus 1205961205962119892119892120576120576 (7)


119892119892119903119903 = 100765310076531205821205821198921198922119892119892100766910076692119889 10076541007654

120582120582119892119892120582120582119892119892119892119892

100767010076702

(8)







prime119892119892 119909119909



prime119892119892 119909119909







oscillator

VSWR meter

Power meter

Gunn power supply

Wave guide cell






119870119870120590120590 119870 119870119870119870119870 119870119870 119870 119870119870119870119870 (9)


119870119870120590120590 119870 119870119870119870119870119870 119870119870 119870 119870119870119870119870119870 (10)


120590120590119870119901119901119901119901119901119901 119872120579120579119872 119870 81198961198964120590120590119870cos41205791205791009250100925012057212057211990111990111990111990112057912057910092501009250

119870119882119882 119872119870119896119896 s119896119896 120579120579119872 119870 (11)



120572120572ℎℎ 119872120579120579119872 119870cos 120579120579 120579 10076501007650120576120576119904119904 120579 sin11987012057912057910076661007666

1119870119870

cos 120579120579 120579 10076491007649120576120576119904119904 120579 sin119870120579120579100766510076651119870119870119870 (12)


120572120572119907119907119907119907 119872120579120579119872 119870 10076491007649120576120576119904119904 120579 110076651007665sin119870120579120579 120579 120576120576119904119904 100765010076501 120579 119870sin

11987012057912057910076661007666

10077151007715120576120576119904119904 cos 120579120579 120579 10076491007649120576120576119904119904 120579 sin11987012057912057910076651007665111987011987010077311007731119870 119870 (13)


119882119882119872119870119896119896 s119896119896 120579120579119872 1198701119870119897119897119870expo 10077141007714120579119872119896119896119897119897 s119896119896 12057912057911987211987010077301007730 119870 (14)







2

25

3

35

4

45

0 2 4 6 8 10 12 14 16 18 20 22

Diesel oil

Soil

Die

lect

ric

per

mit

tivi

ty


Percentage


10 20 30 40 50 60 70 80

Sca

tter

ing

coeffi

cien

t

2()HH

2()VV14()HH

14()VV

21()HH

21()VV

minus10

minus15

minus20

minus25

minus30

minus35

minus40

minus45

minus50

Degree







1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22

Sca

tter

ing

coeffi

cien

t

Diesel weight ()

25(HH)

25(VV)

30(HH)

30(VV)

35(HH)

35(VV)

40(HH)

40(VV)

45(HH)

45(VV)

50(HH)

50(VV)

55(HH)

55(VV)

minus12

minus14

minus16

minus18

minus20

minus22

minus24

minus26

minus28











References

































RoboticsJournal of





Journal of



RotatingMachinery





VLSI Design



Shock and Vibration







Journal of



Volume 2014


SensorsJournal of





Propagation













oscillator

VSWR meter

Power meter

Gunn power supply

Wave guide cell






119870119870120590120590 119870 119870119870119870119870 119870119870 119870 119870119870119870119870 (9)


119870119870120590120590 119870 119870119870119870119870119870 119870119870 119870 119870119870119870119870119870 (10)


120590120590119870119901119901119901119901119901119901 119872120579120579119872 119870 81198961198964120590120590119870cos41205791205791009250100925012057212057211990111990111990111990112057912057910092501009250

119870119882119882 119872119870119896119896 s119896119896 120579120579119872 119870 (11)



120572120572ℎℎ 119872120579120579119872 119870cos 120579120579 120579 10076501007650120576120576119904119904 120579 sin11987012057912057910076661007666

1119870119870

cos 120579120579 120579 10076491007649120576120576119904119904 120579 sin119870120579120579100766510076651119870119870119870 (12)


120572120572119907119907119907119907 119872120579120579119872 119870 10076491007649120576120576119904119904 120579 110076651007665sin119870120579120579 120579 120576120576119904119904 100765010076501 120579 119870sin

11987012057912057910076661007666

10077151007715120576120576119904119904 cos 120579120579 120579 10076491007649120576120576119904119904 120579 sin11987012057912057910076651007665111987011987010077311007731119870 119870 (13)


119882119882119872119870119896119896 s119896119896 120579120579119872 1198701119870119897119897119870expo 10077141007714120579119872119896119896119897119897 s119896119896 12057912057911987211987010077301007730 119870 (14)







2

25

3

35

4

45

0 2 4 6 8 10 12 14 16 18 20 22

Diesel oil

Soil

Die

lect

ric

per

mit

tivi

ty


Percentage


10 20 30 40 50 60 70 80

Sca

tter

ing

coeffi

cien

t

2()HH

2()VV14()HH

14()VV

21()HH

21()VV

minus10

minus15

minus20

minus25

minus30

minus35

minus40

minus45

minus50

Degree







1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22

Sca

tter

ing

coeffi

cien

t

Diesel weight ()

25(HH)

25(VV)

30(HH)

30(VV)

35(HH)

35(VV)

40(HH)

40(VV)

45(HH)

45(VV)

50(HH)

50(VV)

55(HH)

55(VV)

minus12

minus14

minus16

minus18

minus20

minus22

minus24

minus26

minus28











References

































RoboticsJournal of





Journal of



RotatingMachinery





VLSI Design



Shock and Vibration







Journal of



Volume 2014


SensorsJournal of





Propagation














2

25

3

35

4

45

0 2 4 6 8 10 12 14 16 18 20 22

Diesel oil

Soil

Die

lect

ric

per

mit

tivi

ty


Percentage


10 20 30 40 50 60 70 80

Sca

tter

ing

coeffi

cien

t

2()HH

2()VV14()HH

14()VV

21()HH

21()VV

minus10

minus15

minus20

minus25

minus30

minus35

minus40

minus45

minus50

Degree







1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22

Sca

tter

ing

coeffi

cien

t

Diesel weight ()

25(HH)

25(VV)

30(HH)

30(VV)

35(HH)

35(VV)

40(HH)

40(VV)

45(HH)

45(VV)

50(HH)

50(VV)

55(HH)

55(VV)

minus12

minus14

minus16

minus18

minus20

minus22

minus24

minus26

minus28











References

































RoboticsJournal of





Journal of



RotatingMachinery





VLSI Design



Shock and Vibration







Journal of



Volume 2014


SensorsJournal of





Propagation












1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22

Sca

tter

ing

coeffi

cien

t

Diesel weight ()

25(HH)

25(VV)

30(HH)

30(VV)

35(HH)

35(VV)

40(HH)

40(VV)

45(HH)

45(VV)

50(HH)

50(VV)

55(HH)

55(VV)

minus12

minus14

minus16

minus18

minus20

minus22

minus24

minus26

minus28











References

































RoboticsJournal of





Journal of



RotatingMachinery





VLSI Design



Shock and Vibration







Journal of



Volume 2014


SensorsJournal of





Propagation















References

































RoboticsJournal of





Journal of



RotatingMachinery





VLSI Design



Shock and Vibration







Journal of



Volume 2014


SensorsJournal of





Propagation




















RoboticsJournal of





Journal of



RotatingMachinery





VLSI Design



Shock and Vibration







Journal of



Volume 2014


SensorsJournal of





Propagation









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