Maritime network plays an important role in civilian and academic applications. However, traditional maritime communication technologies cannot provide broadband services that can satisfy users' need. In this thesis, we proposed a buoy-based maritime mesh network and analyzed the maritime communication characteristics. Then we proposed a link-state-aware routing protocol to address link blockage problem when routing packets and built a simulator to evaluate the network performance. There are several parts of my work. Firstly, we simulated ocean water field. Jerry Tessendorf proposed a method to create ocean surface based on Phillips spectrum which is a wind-driven, semi-empirical oceanography model. We implemented this algorithm in MATLAB and adjusted a key parameter in this algorithm. Secondly, we proposed a link-state-aware routing protocol. Link stability is related to sea state and instant nodes elevation. In link-state-aware routing protocol, the transmitter will send predicted elevation information to receiver, and receiver will decide if the link is stable in next several seconds based on sea states and node elevation information. Finally, we simulated this mesh network in network simulator 3 (NS3). This simulator will enable users to assess the network performance in various sea states. We also need to build a new mobility model, a new propagation model and implement a collision-free access method (spatial TDMA) model in simulation. / Master of Science / Due to burst growth of network coverage, seamless broadband connectivity has been realized in both our daily life and industrial operations. However, wireless communication coverage fades away when moving just several miles away from the coast. Current marine communication technologies cannot provide stable and broadband service, so we proposed a buoy-based maritime mesh network. In this thesis, we built a network simulator which integrates with several new models after analyzed the dynamic ocean wave motion and maritime communication link characteristics.

<p>The wave field in the Baltic Sea has been modelled for a two-year period with the spectral wave model HYPAS. There is a large seasonal variation in the field and a minor annual one, both reflect the wind variation in the area. Since the Baltic Sea is fetch limited, the dominant wind direction is important for the maximum wave heights.</p><p>By studying the modelled wave energy density in combination with bottom type maps, the effect of the wave field on the sediment surface is examined. Up to half the bottoms in the Baltic Sea are affected ~25% of the time. A statistical relation between wave energy density and bottom types is found for the Gulf of Riga, but in the rest of the area the sediment maps were to coarse. It is, due to this, not possible to say if the result is valid for the whole area or if it is site specific.</p><p>During resuspension events the remineralisation is increased since deposited organic material is reintroduced into the watermass and there exposed to higher levels of oxygen. This process could act as an increased regional source of nitrogen in nutrient budgets and thus influence the conditions for nitrogen fixation and perhaps explain some of the geographical differences in the nitrogen fixation rates.</p>

A 3-axis acoustic Doppler Velocimeter (ADV) with high sampling rate was used to measure the bed shear stress and turbulence under wave-current interaction conditions in this study. Experimental sites include laboratory tank, Love River in Kaohsiung and Howan coastal waters in Pingtung. Bed shear stress is estimated primarily by the inertial dissipation method, also by the turbulent kinetic energy method and eddy correlation method. Results of the laboratory experiments indicate that the bed shear stress increases as both the flow speed and wave height increase, and the flow speed is a more important factor. Field experiments can be divided into several types. The first type is under slow flows and calm waves. Love River is a typical condition of this type with turbid waters and a low flow speed. During the experimental period the ADV correlations reach 90% or more. Because the river flow is quite small, no significant bed shear stress is produced and u* is mostly less than 1 cm/s. As a result the deposition effect is much larger than erosion, thus a very thick layer of mud is formed on the riverbed. The observations in Howan in April 2010 also reveal the condition of slow flows and small waves, and the bed shear stress is also quite small. Due to the factors of clean coastal waters and weak turbulence in this season, the quality of ADV signals is poor. The second type is under large flows and small waves, as shown from the observations of Howan in April 2011, during which the maximum speed reached 25 cm/s and wave heights less than 20 cm. In this experiment the shear stress is large, the u* are mostly greater than 0.8 cm/s and the value of the drag coefficient is 0.0021; the ADV signals have good quality and the inertial sub-range is well defined. The third type is under weak flows and large waves. The observations of Howan in July 2011 show significant rainfall and maximum wave heights of 90 cm. In this case the u* are mostly centered around 1 cm/s. The acoustic backscatter intensity is positively correlated with the turbidity and wave height. Sizable bed shear stress induced by the orbital velocity of waves contributes a significant part to the total bed shear stress.

Approved for public release; distribution is unlimited / Capacitance and conductance measurements using two and four wire techniques were developed and statically and dynamically calibrated in this thesis. The voltage sensitivities range from 7.3 to 8.1 ± 0.1 mV/cm for the two wire capacitance system static calibrations. This is ± 5.2% of the limiting theoretical value. The voltage sensitivities range from 0.3 to 0.4 ± 0.1 V/cm for the four wire conductance system static calibrations. Dynamic calibrations were only completed for the conductance system. The dynamic calibration results were weakly frequency dependent with a qj-0.15 decay in a limited, 2-4 Hz range. Wind power spectrum measurements were taken in the existing Upper Ocean Simulations Facility at the Naval Postgraduate School. There was excellent agreement in the spectra with both techniques. Driven gravity wave frequency downshifting and wind energy dumping was observed in the combined gravity wave and wind-wave measurements. The power spectra peaked near two Hertz and decayed at 50 to 70 dB per decade, or as CO -5 to G)" 7 for both systems. Gravity wave phase speed and wavelength measurements were performed with the capacitance system. The results were approximately 40% higher than theory. / http://archive.org/details/developmentcalib00yarb

Internet of Things (IoT) är ett koncept som fått mycket uppmärksamhet från forskare och utövare av IoT världen över. IoT kan beskrivas som ett nätverk där vardagliga föremål kommunicerar med varandra eller med människor. IoT kommer att bygga ut internet genom att integrera föremål för kommunicering via inbäddade system, detta leder till ett distribuerat nätverk av enheter som kommunicerar med människor och andra IoT-enheter. Härnösand Miljö &amp; Energi AB (HEMAB), är en av ägarna till ServaNet och är ett företag som vill utöka sitt testområde för IoT-sensorer som använder LoRa-teknik för att kommunicera. HEMAB är en av ägarna till ServaNet. Studien har konstruerat metoder för mätning av höjdskillnad från data av en barometer och en accelerometer. Resultatet jämför de två sensorerna med avseende på hur tillförlitligt de kan mäta höjdskillnad över tid. Accelerometern ger mer tillförlitliga resultat som ligger närmare verkligheten, på lägre höjder, med en kortare mätperiod i jämförelse med barometern. Däremot, visar barometern mer tillförlitliga värden på högre höjder, och mer tillförlitligt värde än accelerometern på den högsta testade höjden. Anledningen till att accelerometern ger mindre tillförlitliga resultat på högre höjder med längre mätperiod, beror på det sättet dubbelintegrering tar med sig felande och avstickande värden som blir större och större ju längre tid som integreras. Barometern ger osäkra värden på lägre höjd på grund av att sensorn ger spridda värden redan då den ligger stillastående, detta jämnas ut på högre höjder. LoRaWAN är en lämplig teknik för att kommunicera våghöjd, förutsatt att beräkningar görs på prototypen och endast våghöjden skickas över LoRa, inte sensordata. / Internet of Things (IoT), is a concept that has received a lot of attention from researchers and practitioners of IoT worldwide. IoT can be described as a network where everyday objects communicate with each other or with people. IoT will expand the internet by integrating objects for communication via embedded systems, this leads to a distributed network of devices that communicate with people and other IoT devices. Härnösand Miljö &amp; Energi AB (HEMAB), is one of the owners of ServaNet and is a company that wants to expand its test area for IoT sensors that use LoRa-technology to communicate. HEMAB is one of the owners of ServaNet, as ServaNet is the city network in Härnösand. This study has constructed a method for each sensor that can measure height difference. The result compares a barometer and an accelerometer with respect to how reliably they can measure height difference over time. The accelerometer gives more reliable results that are closer to the reality, at lower altitudes, with a shorter measurement period compared to the barometer. On the other hand, the barometer shows more reliable measurements at higher altitudes, and more accurate measurement than the accelerometer at the highest tested altitude. The reason why the accelerometer performs worse at higher altitudes with longer measurement periods, is due to the way double integration stacks up errors that grows with time, resulting in larger errors for longer periods of measurements. The barometer gives no reliable measurements at lower altitudes, due to the sensor giving scattered values even when the sensor is stationary, this evens out at higher altitudes. LoRaWAN is a suitable technology for communicating wave height, provided that calculations are made on the prototype and only the wave height is sent over LoRa, not sensor-data.  The outcome of the benchmarks measurement showed that increasing the number of nodes would not result in superior performance. It was noted that an optimal number of nodes was found to be between 1 and 20 for all the tests performed. The study showed that no load balancer could be considered a clear winner, instead, different configurations of load balancers performed varyingly well at different tests.

The wave field in the Baltic Sea has been modelled for a two-year period with the spectral wave model HYPAS. There is a large seasonal variation in the field and a minor annual one, both reflect the wind variation in the area. Since the Baltic Sea is fetch limited, the dominant wind direction is important for the maximum wave heights. By studying the modelled wave energy density in combination with bottom type maps, the effect of the wave field on the sediment surface is examined. Up to half the bottoms in the Baltic Sea are affected ~25% of the time. A statistical relation between wave energy density and bottom types is found for the Gulf of Riga, but in the rest of the area the sediment maps were to coarse. It is, due to this, not possible to say if the result is valid for the whole area or if it is site specific. During resuspension events the remineralisation is increased since deposited organic material is reintroduced into the watermass and there exposed to higher levels of oxygen. This process could act as an increased regional source of nitrogen in nutrient budgets and thus influence the conditions for nitrogen fixation and perhaps explain some of the geographical differences in the nitrogen fixation rates.

O presente trabalho aborda o desenvolvimento de um sistema de automação e controle para tanques oceânicos com múltiplos atuadores para possibilitar a geração e absorção ativa de ondas. O desenvolvimento compreende: a implementação e a validação do sistema de automação e controle para o tanque de provas; o desenvolvimento de algoritmos para a geração de ondas com batedores do tipo flap, para atender aos casos tipicamente utilizados em ensaios de estruturas oceânicas, tais como ondas regulares e irregulares, com ou sem espalhamento direcional. O sistema desenvolvido fez uso de controladores do tipo CLP (controlador lógico programável) em rede de comunicação industrial usando troca de dados síncrona, como uma solução robusta de automação. Os controladores desenvolvidos foram estudados individualmente para a devida caracterização e identificação dos limites de desempenho. Sensores de ondas ultrassônicos foram desenvolvidos e caracterizados para medir ondas nos atuadores e viabilizar a malha de controle de absorção ativa do tanque de provas. Sensores de ondas capacitivos foram desenvolvidos e calibrados para a medição de ondas nos ensaios experimentais. A validação experimental do funcionamento do sistema de atuação, controle e sensoriamento foi realizada utilizando os equipamentos desenvolvidos. Os testes foram feitos validando o funcionamento dos atuadores, a geração de ondas regulares, a geração de ondas regulares oblíquas e a geração de ondas irregulares de cristas longas. Os testes apontaram que os atuadores dos cantos do tanque, que são fixos, provocam alterações no campo de ondas, tal como a difração de ondas. As flutuações foram avaliadas onde os valores extremos podem chegar a 58% e foi apresentada uma proposta de medidas paliativas. As ondas regulares e irregulares foram validadas para que o tanque seja capaz de realizar ensaios experimentais reproduzindo as condições ambientais da costa brasileira em ensaios com modelos reduzidos. Foram realizadas medições do coeficiente de reflexão das ondas regulares e irregulares geradas no tanque de provas que mostram valores em torno de 10%. Usando a absorção ativa de ondas em duas laterais opostas do tanque, constatou-se que a segunda reflexão (re-reflexão) afeta fracamente o campo de ondas. A fim de demonstrar o potencial do controlador do tanque, foi desenvolvida uma nova técnica para focalização de energia de ondas em tanque de provas, fundamentada na técnica de TR (time reversal), para concentrar ondas em pontos específicos do espaço. Esta técnica foi originalmente proposta para aplicações usando ultrassom na forma de ondas de pressão acústica, mas, devido à semelhança do fenômeno físico, a técnica foi aplicada às ondas de superfície livre da água. Foram realizados três tipos de testes usando TR, e em todos eles a concentração de ondas foi obtida no local e no instante esperados. Concluiu-se, então, que o método funciona mesmo que existam obstáculos à propagação da onda, como difração e reflexão no interior do tanque de provas. Um dos testes estudou as ondas concêntricas geradas por um objeto lançado contra a água; a aplicação de TR resultou em uma onda concentrada no ponto de lançamento. Os fenômenos observados podem servir de paradigma para comparações numéricas e estudos de ondas em meios dispersivos. / This work discusses the development of an automation and control system for ocean tanks with multiple actuators to enable the generation and active absorption of waves. The development includes: implementation and validation of system automation and control to the ocean wave tank, the development of algorithms for generating waves with flap type wave generator for dealing with cases typically used in tests of ocean structures, such as regular waves and irregular, with or without directional spreading. The developed system used PLC controllers (programmable logic controller) and an industrial communication network with synchronous data exchange, which is a robust automation system solution. The developed controllers were individually studied for proper performance characterization. Ultrasonic wave sensors have been developed and characterized to measure waves in the face of actuators and enable the control loop active absorption of the ocean wave tank. Capacitive wave sensors have been developed and calibrated to measure wave in experimental tests. The experimental validation of system actuation, control and sensing system was performed. Validation tests of the operation of the actuators under regular wave generation, irregular wave generation and oblique regular waves were done. The tests showed that the fixed actuators of the corners of the tank cause changes in the wave field such as diffraction waves. The spatial wave field fluctuations can reach 58% and correction procedures were proposed. Regular and irregular waves were validated for the tank to be able to perform experimental tests reproducing the environmental conditions of the Brazilian coast in reduced model tests of offshore structures. Measurements of the reflection coefficient of regular and irregular waves generated in the test tank indicated values around 10%. Using active absorption of waves in two opposite sides of the tank, it was realized that the re-reflection weakly affects the wave field. In order to demonstrating the innovative potential applications of tank, it was developed a new technique to focus wave energy, based on the technique of TR (time reversal) to concentrate waves at specific points in space. This was originally proposed for applications using ultrasound acoustic pressure waves, but due to the similarity of the physical phenomenon, the technique was applied to the waves in the free water surface. Three types of tests were carried out and in each TR concentration wave was obtained in the expected location and the expected time. It was noticed that the method also works even with obstacles to wave propagation, such as diffraction and reflection inside the ocean wave tank. An object thrown against the water, creating concentric waves was studied and after the application of TR resulted in a wave concentrated at the same splash point. The observed phenomena can be considered as a paradigm for numerical comparisons and studies of waves in dispersive media.

Confined coasts in general, and pocket beach environments in particular, are under huge development pressures worldwide, not least due to their sheltered nature and perceived shoreline stability. However, understanding of their physical functioning is poor in comparison to that of open coast beaches. This study aims to improve understanding in terms of the existing gaps in knowledge of wave processes and nearshore currents, and also to examine the importance of local wind and tide factors in generating nearshore currents, in micro-tidal pocket beaches. The boundaries of embayments are generally recognized as important controls of their beach processes and responses, yet little detailed knowledge exists of how the exact embayment dimensions and characteristics influences these processes. One key embayment feature the influence of which is poorly understood is the downcoast headland. In this thesis, field observations plus Zanuttigh and Van der Meer’s (2008) approach, and the SWAN wave model were used to evaluate the downcoast headland effects on wave processes within Okains Bay, an example pocket beach environment. The results showed that incident wave heights and directions were significantly influenced by wave reflection processes from the downcoast headland inside the bay. The intensity of reflection effects on wave characteristics inside the pocket beach varied according to approaching wave direction. Reflection effects reduced when waves approached from angles close to parallel to the headlands, increasing towards headland-perpendicular wave approaches. Field observations and the XBeach model were used to examine whether or not tides can significantly influence nearshore currents within example and model pocket beach environments. Results indicated that tides can be the primary driver of nearshore currents close to the bed inside micro-tidal pocket beaches, depending on incident wave conditions. In areas of micro-tidal pocket beaches exposed to direct approaching waves, currents were wave driven, while in areas further into the bay that experienced headland filtering of their wave environment, currents were mainly tide generated. The results of this study demonstrated how the current circulation system within micro-tidal pocket beaches is related to the incoming directions of offshore waves. If high energy waves approach oblique or normal to the shoreline (with the assumption that the shoreline is at 90° to the headlands), the current system was found to consist of longshore currents influenced by headlands, plus a rip current in the center of the shoreline or a toporip in proximity to headlands. The location of the rip current or toporip was determined by the direction of approaching incident waves. This study also examined the behavior of local winds in a pocket beach environment and their consequent effects on nearshore currents. Results for Okains Bay show that local winds tended to blow in offshore and onshore directions, as the bay is located in a valley, so orographic effects channel and shift the wind directions to angles close to offshore and onshore directions inside the bay. Results also indicated that local winds influence the hydrodynamic currents of pocket beaches that are confined by elevated topography, producing semi-cross shore influences since the winds are topographically channelled to blow in predominantly offshore and onshore directions. This research significantly refines our understanding of micro-tidal pocket beach wave and current processes, including quantification of the filtering effects of headlands on their wave environments, revealing the various and variable influences of tides and winds compared to in open coast beaches; and, significantly, highlighting the role of downcoast headland wave reflection effects. With regard to the latter, this research elucidates some key process differences between pocket and embayed beaches and clarifies reasons why the application of embayed beach models that include refraction and diffraction but exclude reflection effects to the study of pocket beaches is inappropriate for studying pocket beaches. This research also provides methodological and topic suggestions for future research on pocket beach environments, including how to use the improved hydrodynamic knowledge of this study in future studies seeking to better understand pocket beach sediment systems, a topic that was beyond the scope of the current research.

O presente trabalho aborda o desenvolvimento de um sistema de automação e controle para tanques oceânicos com múltiplos atuadores para possibilitar a geração e absorção ativa de ondas. O desenvolvimento compreende: a implementação e a validação do sistema de automação e controle para o tanque de provas; o desenvolvimento de algoritmos para a geração de ondas com batedores do tipo flap, para atender aos casos tipicamente utilizados em ensaios de estruturas oceânicas, tais como ondas regulares e irregulares, com ou sem espalhamento direcional. O sistema desenvolvido fez uso de controladores do tipo CLP (controlador lógico programável) em rede de comunicação industrial usando troca de dados síncrona, como uma solução robusta de automação. Os controladores desenvolvidos foram estudados individualmente para a devida caracterização e identificação dos limites de desempenho. Sensores de ondas ultrassônicos foram desenvolvidos e caracterizados para medir ondas nos atuadores e viabilizar a malha de controle de absorção ativa do tanque de provas. Sensores de ondas capacitivos foram desenvolvidos e calibrados para a medição de ondas nos ensaios experimentais. A validação experimental do funcionamento do sistema de atuação, controle e sensoriamento foi realizada utilizando os equipamentos desenvolvidos. Os testes foram feitos validando o funcionamento dos atuadores, a geração de ondas regulares, a geração de ondas regulares oblíquas e a geração de ondas irregulares de cristas longas. Os testes apontaram que os atuadores dos cantos do tanque, que são fixos, provocam alterações no campo de ondas, tal como a difração de ondas. As flutuações foram avaliadas onde os valores extremos podem chegar a 58% e foi apresentada uma proposta de medidas paliativas. As ondas regulares e irregulares foram validadas para que o tanque seja capaz de realizar ensaios experimentais reproduzindo as condições ambientais da costa brasileira em ensaios com modelos reduzidos. Foram realizadas medições do coeficiente de reflexão das ondas regulares e irregulares geradas no tanque de provas que mostram valores em torno de 10%. Usando a absorção ativa de ondas em duas laterais opostas do tanque, constatou-se que a segunda reflexão (re-reflexão) afeta fracamente o campo de ondas. A fim de demonstrar o potencial do controlador do tanque, foi desenvolvida uma nova técnica para focalização de energia de ondas em tanque de provas, fundamentada na técnica de TR (time reversal), para concentrar ondas em pontos específicos do espaço. Esta técnica foi originalmente proposta para aplicações usando ultrassom na forma de ondas de pressão acústica, mas, devido à semelhança do fenômeno físico, a técnica foi aplicada às ondas de superfície livre da água. Foram realizados três tipos de testes usando TR, e em todos eles a concentração de ondas foi obtida no local e no instante esperados. Concluiu-se, então, que o método funciona mesmo que existam obstáculos à propagação da onda, como difração e reflexão no interior do tanque de provas. Um dos testes estudou as ondas concêntricas geradas por um objeto lançado contra a água; a aplicação de TR resultou em uma onda concentrada no ponto de lançamento. Os fenômenos observados podem servir de paradigma para comparações numéricas e estudos de ondas em meios dispersivos. / This work discusses the development of an automation and control system for ocean tanks with multiple actuators to enable the generation and active absorption of waves. The development includes: implementation and validation of system automation and control to the ocean wave tank, the development of algorithms for generating waves with flap type wave generator for dealing with cases typically used in tests of ocean structures, such as regular waves and irregular, with or without directional spreading. The developed system used PLC controllers (programmable logic controller) and an industrial communication network with synchronous data exchange, which is a robust automation system solution. The developed controllers were individually studied for proper performance characterization. Ultrasonic wave sensors have been developed and characterized to measure waves in the face of actuators and enable the control loop active absorption of the ocean wave tank. Capacitive wave sensors have been developed and calibrated to measure wave in experimental tests. The experimental validation of system actuation, control and sensing system was performed. Validation tests of the operation of the actuators under regular wave generation, irregular wave generation and oblique regular waves were done. The tests showed that the fixed actuators of the corners of the tank cause changes in the wave field such as diffraction waves. The spatial wave field fluctuations can reach 58% and correction procedures were proposed. Regular and irregular waves were validated for the tank to be able to perform experimental tests reproducing the environmental conditions of the Brazilian coast in reduced model tests of offshore structures. Measurements of the reflection coefficient of regular and irregular waves generated in the test tank indicated values around 10%. Using active absorption of waves in two opposite sides of the tank, it was realized that the re-reflection weakly affects the wave field. In order to demonstrating the innovative potential applications of tank, it was developed a new technique to focus wave energy, based on the technique of TR (time reversal) to concentrate waves at specific points in space. This was originally proposed for applications using ultrasound acoustic pressure waves, but due to the similarity of the physical phenomenon, the technique was applied to the waves in the free water surface. Three types of tests were carried out and in each TR concentration wave was obtained in the expected location and the expected time. It was noticed that the method also works even with obstacles to wave propagation, such as diffraction and reflection inside the ocean wave tank. An object thrown against the water, creating concentric waves was studied and after the application of TR resulted in a wave concentrated at the same splash point. The observed phenomena can be considered as a paradigm for numerical comparisons and studies of waves in dispersive media.

In May of 2000 Jason-1, a joint project between NASA and the French space agency CNES, will be launched. Its mission is to continue the highly successful gathering of data which TOPEX/Poseidon has collected since August of 1992. The main goal of Jason-1 is to achieve higher accuracy in measuring the mean sea level (MSL). In order to do so, the electromagnetic (EM) bias must be estimated more accurately because it is the largest contributing error. This thesis presents two different studies which add to the knowledge and improve estimation of the EM bias, and thus assists Jason-1 in achieving its primary goal. Oceanographic data collected from two different experiments are analyzed; on in the Gulf of Mexico (GME) and the other in Bass Strait, Australia (BSE). The first study is a spatial analysis of the backscattered power versus the phase of the wave. Its purpose is to determine why the normalized EM bias stops increasing and levels out at high wind speeds (about 11 m/s) and then decreases at higher wind speeds. Two possible causes are investigated. First, it could be due to a shift in the backscatter power modulation to the forward or rear face of the wave crests. Second, it may be due to the backscatter power becoming more homogeneous throughout the wave profile. This study is novel because it uses the knowledge of the spatial distribution of both the backscatter and wave displacement for the study of the EM bias. Both contribute to the EM bias decrease, but the latter cause seems to be the dominant effect. This study is performed on GME data. The second study uses two different nonparametric regression (NPR) techniques to estimate the EM bias. A recent study of satellite data from the TOPEX/Poseidon altimeter supports that the bias is modeled better using NPR regression. A traditional parametric fit is compared to two NPR techniques with GME data. The parametric fit is a variation of NASA's equation used to estimate EM bias for their Geophysical Data Records (GDRs). The two NPR techniques used are the Nadaraya-Watson Regression (NWR) and Local Linear Regression (LLR) estimators. Two smoothing kernel functions are used with each NPR technique, namely the Gaussian and the Epanechnikov kernels. NPR methods essentially consist of statistically smoothing the measured EM bias estimates are compared in the wind and significant wave height plane. Another recent study has shown that wave slope is strongly correlated to EM bias. With this knowledge, EM bias is estimated over several two-dimensional planes which include wave slope in attempt to reduce the residual bias. This portion of the study is performed on GME and BSE data. It is shown that a combination of slope, significant wave height, and wind speed used in conjunction with these NPR methods produces the best EM bias estimate for tower data.