• Design and implementation of novel radar modulations for the SuperDARN radar at Kodiak Island, Alaska

      Balaji, Mrinal S. (2007-05)
      The Kodiak SuperDARN (Super Dual Auroral Radar Network), located on Kodiak Island, Alaska, is a coherent-backscatter radar sensitive to Bragg scatter from ionospheric irregularities. SuperDARN transmitters send out a sequence of seven pulses that aid in the formation of complex autocorrelation functions (ACFs). These ACFs allow for estimating the power, velocity and the spectral widths of the scattering plasma waves. However, the multipulse sequence used currently has some characteristics that are not ideal for the intended purpose. In addition, the analysis technique for estimating the properties of the ACF assumes that there is only a single velocity component present in each range cell at one time. In this study, the aperiodic radar technique designed by Dr. John D. Sahr and Dr. Sathyadev. V. Uppala was investigated to design an optimized transmission sequence that would have no repeated lags, a minimum number of inherently missing lags and no loss of lags due to Tx-on/Rx-off conflicts. With the designed transmission sequence, efficient analysis of data is possible through the use of a standard spectral estimator, the modified covariance technique. The design enhances the ability of the radar to discriminate targets in the same range bin.
    • Design and implementation of photodiode-based receiver systems for a 1574 nm eye-safe lidar

      Yue, Jia (2004-08)
      In this thesis we present the design, implementation and testing of a photodiode-based receiver systems for a 1574 nm eye-safe lidar. The specific goal of this thesis was to precisely and accurately convert and amplify nW optical signals into robust mV voltage signals. The receiver system incorporates both analog and digital circuitry and a software-based digital processing system. Four analog circuits were constructed and tested using both PIN diodes and APDs, and two high-speed commercial op amps. A single high-speed digital processing system was tested with each of the analog circuits. The analog circuitry was found to be the fundamental limitation on the performance of the system with the receiver bandwidth limited to -6 MHz for the PIN-based systems and -14 MHz for the APD-based systems. Inherent oscillations in the analog circuits were successfully removed using digital filtering techniques in the software-based digital processing systems. Furthermore, the APD-based systems had less rms noise than the PIN-based systems. The lidar receiver system could support measurements with a maximum resolution of 10 m and a range of up to 40 km.
    • Design and simulation of flight computer using VHDL for ARIM-1 sounding rocket payload

      Chowdhury, Anirban (2000-12)
      Atmospheric Refractive Index Measurement-1 (ARIM-1) is a sounding rocket payload designed to collect information regarding atmospheric turbulence. ARIM-1 is designed to make high-resolution (4 samples per centimeter) differential temperature measurements of the atmosphere to determine the structure of atmospheric turbulence and hence it's refractive index. The rocket's flight computer schedules and manages data acquisition from various payload sub-systems and transmits this acquired data to the ground station. The goal of this work is to develop a custom design for this flight computer using Very High Speed Integrated Circuit Hardware Description Language (VHDL). This thesis presents simulation and hardware requirements for the flight computer generated from a professional Computer Aided Design package used for VHDL design implementation. This thesis proposes a new architecture for the flight computer that can be implemented with Programmable Logic Devices using VHDL.
    • Design of a fast telemetry encoder for sounding rockets

      Hatfield, Gaelen C. (2005-12)
      This thesis describes the design, development, implementation and testing of the FOXIE-03 (Frame Oriented eXpandable Integrated-circuit Encoder, Designed in 2003) Telemetry System. This system was developed for the University of Alaska Fairbanks Alaska Space Grant Program (UAF / ASGP) to serve as a sounding rocket data encoder for current and future Alaska Student Rocket Project (ASRP) missions. The encoder provides compatibility with the IRIG106-01 telemetry standard and NASA telemetry downlink systems. The encoder provides a full complement of analog and digital inputs. The encoder also provides a cross-platform USB interface for easy configuration. The first flight of the FOXIE-03 system is expected to be aboard the U AF ISIS (Ionospheric Science and Inertial Sensing) Mission which will be launched from Poker Flat Research Range in early 2007. The FOXIE-03 Telemetry system was delivered in a year's time. Extensive testing is ongoing and will lead to its acceptance as space flight certified hardware for the Alaska Space Grant Program.
    • Design of a flexible and low-power ionospheric sounder

      Morris, Alex; Bristow, William; Hawkins, Joseph; Sonwalkar, Vikas (2014-05)
      Characterizing the structure of the ionosphere has practical applications for telecommunications and scientific applications for studies of the near-earth space environment. Among several methods for measuring parameters of the ionosphere is ionospheric sounding, a radar technique that determines the electron content of the ionosphere as a function of height. Various research, military, and commercial institutions operate hundreds of ground-based ionosondes throughout the globe, and new ionosondes continue to be deployed in increasingly remote and distant locations. This thesis presents the design of an ionospheric sounder that reduces the power, size, and cost compared to existing systems. Key improvements include the use of an open-source software-defined radio platform and channel-aware dynamic sounding scheduling.
    • Design of a multichannel outdoor data logger for precise temperature measurements

      Dolgikh, Kirill; Raskovic, Dejan; Romanovsky, Vladimir; Thorsen, Denise (2018-12)
      In this thesis, we present the prototype of a multichannel data logger (the Logger) for precise temperature measurements. Its intended application is to take soil (permafrost) temperature measurements with a thermistor probe or thermistor string. However, its hardware and firmware architectures are quite flexible, so it can be used in other applications. The Logger has 16 channels. In addition to the internal memory, it supports microSD-cards of up to 2 GB, which allows it to store up to 41.9 million measurements for each channel. The Logger's estimated battery life is 8 years when making measurements once per hour. It has a radio transmitter, which will allow it to download data wirelessly and potentially participate in a wireless sensor network once the appropriate firmware is developed. Currently, only the communication protocol with the radio is implemented, while the radio-to-radio protocol is under development. The Logger is small - only 6 x 1 x 1 inches and the final product will be even smaller. Components are rated down to -40° C and the Logger successfully passed testing at -30° C. After the extensive testing to ensure performance it has been shown that the Logger outperforms the Campbell Scientific, Inc. CR1000 logger and exceeds the design requirements. Measured temperature resolution of the Logger is below 2.5 mK in the entire temperature range. The Logger's equivalent temperature accuracy, which was determined using a known resistive input, is below 10 mK within -25° C to 40° C and below 20 mK elsewhere. The developed calibration technique provides the equivalent accuracy below 0.3 mK within -40° C to 40° C. To provide an accuracy of ±0.01° C when making temperature measurements with thermistors, the Logger should be calibrated against a thermometer that has been calibrated as a secondary standard, which will be done in the future.
    • Design of a receiver for measurement of real-time ionospheric reflection height

      Raghavendar, Changalvala (2005-08)
      The HF (high frequency) radar at Kodiak Island, Alaska, is part of the SuperDARN (Super Dual Auroral Radar Network) network of radars designed to detect echoes from ionospheric field-aligned density irregularities. Normal azimuth scans of the radar begin on whole minute boundaries leading to 12 s downtime between each scan. The radar makes use of this down time, by stepping through eight different frequencies for each beam direction using 1 or 2 s integration periods. A new receiver system has been developed at Poker Flat Research Range (PFRR), to utilize the ground scatter returns from radar's sounding mode of operation and calculate the ionospheric virtual reflection height. This would result in considerable improvement in the accuracy of critical frequency and Angle Of Arrival (AOA) estimations made by the Kodiak SuperDARN.
    • Design of a wireless sensor network platform and testing environment

      Vadlamani, Srikar; Raskovic, Dejan; Mayer, Charles; Thorsen, Denise (2005-05)
      In this thesis, we present the design and implementation of a wireless sensor network platform and testing environment, for energy efficient, centralized Wireless Sensor Network (WSN) architecture. The entire design process for an energy efficient sensor network requires several design considerations, from component selection for the design of sensor nodes, to the design of a power efficient application specific communication protocol. This thesis provides an insight into all these design considerations. We also discuss tools and techniques for the analysis and assessment of the performance and energy efficiency of a chosen sensor node design. We present a comprehensive design and analysis of sensor node architecture, including a survey of sensor node platforms and energy management techniques. Hardware choices, as well as software solutions, will be discussed. Software components that act as device drivers are briefly explained in this work. We also define and present a sensor node emulator, used to emulate a number of sensors, which can be used in other projects.
    • A Design of an nterface Board between a MRC Thermistor Probe and a Personal Computer

      Raskovic, Dejan (2013-09-30)
      The main purpose of this project was to design and build a prototype of an interface board between an MRC temperature probe (thermistor array) and a personal laptop computer. This interface board replaces and significantly improve the capabilities of an existing MRC RD100 readout instrument. The new interface board provides the user to test a new installation as well as read instantaneous thermistor array. The report also documents the outputs of the the MRC temperature probe for future and the operational characteristics of both the MRC RD100 and the new interface board.
    • Design of circularly polarized, omnidirectional microstrip sounding rocket antennas for telemetry and GPS applications

      Sullins, Ty (2001-08)
      The orientation of a sounding rocket with respect to ground stations or GPS satellites is often highly variable and sometimes unpredictable due to its trajectory and spin. Therefore, a sounding rocket antenna should have a radiation pattern that is nearly omnidirectional to ensure sufficient signal strength in any direction, and the antennas should be circularly polarized to minimize polarization loss. Microstrip antennas are well suited to meet these requirements because they are low profile, lightweight, durable, and can be conformed to nonplanar geometries. Additionally, circularly polarization can be achieved using simple geometries and small size. This dissertation presents the theory and equations required to design common microstrip antennas. Circularly polarized telemetry and GPS antennas are designed for sounding rocket payloads with 6, 8, and 14-inch diameters, and their performance is compared with linearly polarized antennas. A circularly polarized antenna for a 14-inch diameter rocket payload is fabricated and it measured performance compared with theoretical predictions.
    • Design of microcontroller based generic radar controller

      Kolatkar, Aditi (2004-05)
      Increasingly radar stations contain multiple radar systems, each individually controlled. Non-standard control requires that a user of multiple systems learn each system separately. Additionally, multiple radar controllers make coordination of multiple systems difficult. The goal of this thesis is to design a generic radar controller that can be used to operate any pulsed radar system or multiple radar systems simultaneously. The Generic Radar Controller attempts to meet and improve upon the specifications of a previous radar controller and collapse its rack-mounted system into a single PC card. The University of Alaska Generic Radar Controller (UAF-GRC) is a microcontroller based PC card with a minimum of 16 control channels. Each channel can be individually programmed to provide pulses of 400 ns duration up to several milliseconds and variable pulse repetition intervals with a timing resolution of 10 ns. The hardware and software issues that appeared during the design phase are discussed in the thesis. The thesis concludes with improvements of UAF-GRC over the previous radar controller.
    • Detecting Methane Ebullition In Winter From Alaskan Lakes Using Synthetic Aperture Radar Remote Sensing

      Engram, Melanie J.; Walter, Katey (2012)
      Methane (CH4) is a greenhouse gas with a high radiative forcing attribute, yet large uncertainties remain in constraining atmospheric CH4 sources and sinks. While freshwater lakes are known atmospheric CH4 sources, flux through ebullition (bubbling) is difficult to quantify in situ due to uneven spatial distribution and temporally irregular gas eruptions. This heterogeneous distribution of CH4 ebullition also creates error when scaling up field measurements for flux estimations. This thesis reviews estimates of CH4 contribution to the atmosphere by freshwater lakes presented in current literature and identifies knowledge gaps and the logistical difficulties in sampling CH 4 flux via ebullition (bubbling). My research investigates various imaging parameters of space-borne synthetic aperture radar (SAR) to constrain current CH4 emissions from northern lakes. In a GIS spatial analysis of lakes on the northern Seward Peninsula, Alaska, comparing field data of ebullition to SAR, I found that SAR L-band backscatter from lake ice was high from lakes with CH4 bubbles trapped by lake ice and low from lakes with low ebullition activity. The 'roughness' component of a Pauli polarimetric decomposition of quad-pol SAR showed a significant correlation with the percentage of lake ice area containing CH4 bubbles and with CH4 ebullition flux. This indicates that the mechanism of SAR scattering from ebullition bubbles trapped by lake ice is single bounce. I conclude that SAR remote sensing could improve our ability to quantify lake ebullition at larger spatial scales than field measurements alone, could offer between-lake comparison of CH 4 ebullition activity, and is a potential tool for developing regional estimations of lake-source CH4.
    • Detection of F-region electron density irregularities using incoherent-scatter radar

      Gudivada, Krishna Prasad; Watkins, Brenton; Sonwalkar, Vikas; Bristow, William (2014-08)
      Incoherent-scatter radar data from Poker Flat, Alaska has been used to determine size distributions of electron density structures in the evening time sector of the auroral zone. At high latitudes ionospheric plasma typically moves east-west with speeds of several hundred meters per second. Density irregularities that rapidly move through the radar beam are therefore observed as time-varying power fluctuations. The new phased array radar used for this study has been operated with several antenna directions with successive pulses transmitted in each direction. It is therefore possible to observe plasma Doppler velocities in multiple directions and determine the vector direction of the plasma motion. This near-simultaneous observation of the plasma velocity in conjunction with the electron density height profile data enable a new technique to determine the scale sizes of electron density fluctuations that move horizontally through the radar beam. The study focuses on the collision-less F-region ionosphere where the plasma drift is approximately constant with altitude. The experimental technique limits the range of scale sizes that may be studied to relatively large-scale sizes (i.e. greater than few tens of km). Results show that during magnetically disturbed conditions (Kp ≥ 4) when westward plasma velocities are relatively high (500-1000 m/s) the scale sizes of irregularities (often called plasma blobs) are in the range of 100-300 km and predominantly originate from the polar cap and are transported over long distances (~1000 km) due to the long chemical recombination times (30-90 minutes). Some irregularities are caused by local auroral particle precipitation and have been identified with associated electron temperature enhancements. For cases of low magnetic activity (Kp ≤ 1), when the radar is located in a region of low plasma velocities (100-500 m/s) well south of the auroral oval (essentially a mid-latitude type ionosphere), the density distribution is always biased strongly toward small-scale sizes (less than 50 km).
    • Determination mercury in Alaskan coals by flameless atomic absorption

      Rao, P.D. (University of Alaska Mineral Industry Research Laboratory, 1973)
      An oxygen combustion, double gold amalgamation system is constructed for the determination of mercury in Alaskan coals. Solutions have been found for certain problems in design and operation. The effect of operating variables have been thoroughly evaluated and analytical procedure is outlined. The system involves combustion of goal in an oxygen atmosphere and amalgamating mercury on gold coils. The amalgamated mercury is released by heating and measured in an atomic absorption cell.
    • Determination of lateral inflows in the Kuparuk River watershed, a study in the Alaskan Arctic

      Overbeck, Levi D.; Kane, Douglas; Stuefer, Svetlana; Toniolo, Horacio (2015-05)
      The objectives of this research were to investigate the relationships between lateral inflows and watershed characteristics within the Kuparuk watershed of Arctic Alaska, as well as to quantify the lateral inflows to be used as an input for calibrating and running a process-based instream water temperature model. Determination of lateral inflows was accomplished by constructing hydrographs at multiple locations along Imnavait Creek and the Kuparuk River using stage and discharge field measurements. The hydrographs were then routed between gauging stations downstream (starting upstream) using the Muskingum routing method; and finally subtracting the routed hydrograph from the downstream measured hydrograph to calculate any additional water that had entered the reach between gauging stations. Results showed, as a general trend, that reaches within the northern foothills of the Brooks Range experienced larger lateral inflow contributions per square kilometer and had larger runoff ratios than subsequent reaches to the north where the terrain flattens out and transitions into the coastal plain. Two reaches within the watershed contradicted the general trend. The low-gradient reach nearest to the Arctic Ocean experienced larger lateral inflows throughout the summer that were unaffected by rainfall precipitation events; this is believed to be caused by snowmelt water initially stored in the low gradient terrain and slowly released into the drainage network during summer months. This area is rich with wetlands, ponds, and lakes and snow-damming during break up is prevalent. The other reach was located upstream of the Kuparuk aufeis field and was observed to lose water during the summer of 2013, supporting a hypothesis that the aufeis formation in this area is fed throughout the winter by a large talik upstream.
    • Determination of methane hydrate stability zones in the Prudhoe Bay, Kuparuk River, and Milne Point units on the North Slope of Alaska

      Westervelt, Jason V. (2004-05)
      Estimates range from approximately 37 to 44 trillion cubic feet of in-place gas in methane hydrate from within the Eileen Trend of the Prudhoe Bay (PBU), Kuparuk River (KRU), and Milne Point (MPU) Units on the North Slope of Alaska (Collett, 1993). This study was based on measuring pressure and temperature conditions for hydrate dissociation. The results showed that the depth of the hydrate stability zone (HSZ) ranges from 585 to 780 meters. The results from this study also show that the HSZ in the Alaska North Slope (ANS) is thinning westward. This study also showed that the effect of formation brines typically found on the North Slope only affects the depth of the hydrate stability zone by 30 to 45 meters when a porous media is not present. Experiments carried out on a porous media sample provided by the Anadarko Corporation showed that the formation brines only affect the depth of the hydrate stability zone by 10 to 15 meters. Geothermal gradients, gas composition, and the type of porous media play the biggest role in the thickness of the HSZ. These variables are also the most important when determining the depth to the HSZ.
    • Determination of molybdenum in geological materials

      Rao, P.D. (University of Alaska Mineral Industry Research Laboratory, 1971-09)
      This paper will describe a method for the determination of molybdenum in geological materials. It is known that molybdenum as molybdate or phosphomolybdate ion can be extracted using the liquid ion exchanger, Aliquat 336 (methyl tricapryl ammonium chloride, available from General Mills, Inc. Kankakee, Ill.). Aliquat 336 has been used for analytical separation of gold, tungsten, and actinide-lanthanide elements.
    • Determination of Seasonal, Frequency and Durational Aspects of Streamflow with Regard to Fish Passage Through Roadway Drainage Structures

      Ashton, William S.; Carlson, Robert F. (1984-11)
      Optimal design of culverts for fish passage for each stream crossing requires the magnitude, duration, frequency and seasonal relationship of the flow and the timing of fish movement. Although previous studies have measured fish swimming abilities and culvert water velocity profiles, there are limited studies in northern regions of the hydrologic relationship among magnitude, duration, frequency and season of discharge for the design of culverts for fish passage. We analyzed streamflow records from 33 gaging stations in southcentral, western, interior, and arctic Alaska (from watersheds with a drainage area less than 100 sq. miles each) to determine the highest consecutive mean discharge with one-, three-, seven and fifteen-day durations, and the lowest consecutive mean discharge with three-, seven-, fourteen- and thirty-day durations. Streamflow during three seasons were analyzed: spring, April 1 to June 30; summer, July 1 to August 31; and fall, Septermber 1 to November 30. The lognormal distribution, using the Blom plotting position formula, was used to estimate flows at recurrence intervals of 1.25, 2, 5, 10 and 20 years. Multiple linear regression equations were developed to predict flows from ungaged watersheds. Significant basin and climatic characteristics for high flows were drainage area, mean annual precipitation and percent of the drainage basin with forest cover. Significant characteristics at low flows were drainage area, mean minimum January temperature, mean annual precipitation and percent of drainage basin covered by forests. This report provides the culvert designer with equations to predict flows, other than the instantaneous peak flow, for use in designing culverts for fish passage. Two example problems are given to show the application of these equations.
    • The determination of titanium in titaniferous magnetite ores by atomic absorption spectrophotometry

      Rao, P.D. (University of Alaska Mineral Industry Research Laboratory, 1972-03)
      Amos and Willis (1) first investigated the use of nitrous oxide for the determination of titanium. They found that the presence of HF and iron enhance the absorption of titanium. They recommended “much more extensive investigation before a practicing chemical analyst can determine this element in a routine fashion by atomic absorption.” Various authors (2, 3, 4, 5, 6) have investigated titanium by atomic absorption and have recommended a number of different procedures to remove interference. In attempting to analyze lithium metaborate fusions (7, 8) of titaniferous magnetite ores of Alaska by atomic absorption, it was found that the interferences are not completely removed by any single approach suggested in the literature. Silicon, iron and aluminum could vary widely between samples and an approach was needed that would completely eliminate interference effects of all these elements, without having to match the gross matrix composition of samples and standards.
    • Develop a Regional Multi-Source Database System for Safety Data Management and Analysis in RITI Communities in Washington State

      Wang, Yinhai; Zeng, Ziqiang; Gottsacker, Christopher; Yang, Hao (Frank) (2019-05)
      Rural, Isolated, Tribal, and Indigenous (RITI) communities across the United States are disadvantaged from a transportation safety perspective. Particular concern is focusing on rural road safety. Since RITI communities often do not have the capability and resources to sufficiently solve roadway safety problems, several challenges are encountered for addressing transportation safety issues in RITI communities, including: (1) Crashes are often distributed along roads in RITI areas without known patterns; (2) Strategies to address safety issues are diverse for different RITI communities and draw from several safety areas. As a result, there is a critical need to realize equitably-augmented safety solutions that address the needs of these underserved and underinvested RITI communities. To address this gap, this project aims to develop a regional multi-source database system for traffic safety data management and analysis of RITI communities in Washington State. The existing crash data sources in RITI communities in Washington was identified and documented. The crash data on rural routes was extracted from the raw data from Washington State Department of Transportation and integrated into the multi-source database system, including traffic flow characteristics, crash attributes and contribution factors, crash-related trauma data and medical records, weather conditions, etc. The Colville tribe also provided the crash data in their tribal communities under a confidentiality agreement. A multi-source database fusion and integration system architecture was designed. Microsoft SQL Server 2012 was used to implement the database and manage the data. A six-step data quality control method was employed to clean the data by wiping out the outliers from spatial and temporal aspects. The tribal crash data was made accessible to authorized users so they can download the datasets by using password, while the WSDOT crash data was set to be public for all the users. A safety analysis module was developed for visualizing the data in the regional multi-source database system in RITI communities. The data visualization platform is developed based on the Vaadin Framework. The users can interact with the interface for data analysis. A safety performance index and a potential safety improvement index were also developed. By combining the two indexes, one can easily identify crash hotspots and the key influencing factors to consider in an improvement package.