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The KnowledgeBank at OSU (74.597 recursos)

Knowledge Bank contains collections of presentations, publications and reports related to Ohio State University.

Reports, Geodetic Science and Surveying, School of Earth Sciences

Mostrando recursos 1 - 20 de 57

  1. Linear Features in Photogrammetry

    Habib, Ayman; Asmamaw, Andinet; Kelley, Devin; May, Manja
    This research addresses the task of including points as well as linear features in photogrammetric applications. Straight lines in object space can be utilized to perform aerial triangulation. Irregular linear features (natural lines) in object space can be utilized to perform single photo resection and automatic relative orientation. When working with primitives, it is important to develop appropriate representations in image and object space. These representations must accommodate for the perspective projection relating the two spaces. There are various options for representing linear features in the above applications. These options have been explored, and an optimal representation has been chosen. An aerial triangulation technique that utilizes points and straight...

  2. Airborne Vector Gravimetry Using GPS/INS

    Kwon, Jay Hyoun, 1967-
    Compared to the conventional ground measurement of gravity, airborne gravimetry is relatively efficient and cost-effective. Especially, the combination of GPS and INS is known to show very good performances in the range of medium frequencies (1-100 km) for recovering the gravity signal. Conventionally, gravity estimation using GPS/INS was analyzed through the estimation of INS system errors using GPS position and velocity updates. In this case, the complex navigation equations must be integrated to obtain the INS position, and the gravity field must be stochastically modeled as a part of the state vector. The vertical component of the gravity vector is not estimable in this case because of the instability...

  3. Static and Kinematic Absolute GPS Positioning and Satellite Clock Error Estimation

    Han, Shin-Chan, 1975-
    This study presents the results of investigations to determine accurate position coordinates using the Global Positioning System in the absolute (point) positioning mode. The most common method to obtain accurate positions with GPS is to apply doubledifferencing procedures whereby GPS satellite signals are differenced at a station and these differences are again differenced with analogous differences at other stations. The differencing between satellites eliminates the receiver clock errors, while the betweenstation differences eliminate the satellite clock errors (as well as other errors, such as orbit error). However, only coordinate differences can be determined in this way and the accuracy depends on the baseline length between cooperating stations. The...

  4. INS, GPS, and Photogrammetry Integration for Vector Gravimetry Estimation

    Dwaik, Fathi Y., 1964-
    Vector gravimetry using Inertial Navigation System (INS) in semi-kinematic mode has been successfully applied. The integration of INS with other sensors, Global Positioning System (GPS) or Gradiometer, for instance, has been under investigation for many years. This dissertation examines the effect of photogrammetric derived orientation on the INS sensor’s calibration and estimation of the gravity vector. The capability of such integration in estimating the INS biases and drifts is studied. The underlying principle, mathematical models, and error sources are presented and analyzed. The estimation process utilizes the measurements of the Litton LN-100 inertial system, Trimble 4000 SSI GPS dual frequency receiver, and metric frame camera. An optimal filtering technique...

  5. Automatic Recognition and Location of Civil Infrastructure Objects Using Mobile Mapping Technology, Neural Network and Markov Chain Monte Carlo

    Li, Ron; Tu, Zhuowen
    Project Report (November 1998 – December 1999). Submitted to The OSU Center For Mapping.

  6. GRACE Time-Variable Gravity Field Recovery Using an Improved Energy Balance Formalism

    Shang, Kun
    Earth’s gravity is continuously varying with respect to time due primarily to mass transports within the Earth system and external gravitational forcing. A new formalism based on energy conservation principle for time-variable gravity field recovery using satellite gravimetry has been developed and yields more accurate estimation of in-situ geopotential difference observables using K-Band Ranging (KBR) measurements from the Gravity Recovery and Climate Experiment (GRACE) twin-satellite mission. The new approach can preserve more time-variable gravity information sensed by KBR range-rate measurements and reduce orbit error as compared to previous energy balance studies. Results based on analysis of more than 10 years of GRACE data indicate that the estimated geopotential differences...

  7. Source Parameters Inversion for Recent Large Undersea Earthquakes from GRACE Data

    Dai, Chunli
    The north component of gravity and gravity gradient changes from the Gravity Recovery And Climate Experiment (GRACE) are used to study the coseismic gravity change for five earthquakes over the last decade: the 2004 Sumatra-Andaman earthquake, the 2007 Bengkulu earthquake, the 2010 Maule, Chile earthquake, the 2011 Tohoku earthquake, and the 2012 Indian Ocean earthquakes. We demonstrate the advantage of these north components to reduce north-south stripes and preserve higher spatial resolution signal in GRACE Level 2 (L2) monthly Stokes Coefficients data products. By using the high spherical harmonic degree (up to degree 96) data products and the innovative GRACE data processing approach developed in this study, the...

  8. Geophysical Investigations on Gravity Gradiometry and Magnetic Data over the Wichita Uplift Region, Southwestern Oklahoma

    Erkan, Kamil
    The Wichita uplift in southwestern Oklahoma is a unique region that shows strong gravity and magnetic field anomalies. Detailed geologic data as well as structural cross sections are also available for the region. This report includes a qualitative geophysical analysis of the airborne gravity gradiometer profiles, and a quantitative analysis of an airborne magnetic field data collected in the region. Two datasets were analyzed independently. Firstly, an effort has been made by comparative analyses of different gravity gradient components with the gravity field from EGM2008 side by side in order to understand the nature of the subsurface structural setting. Secondly, a spectral analysis of magnetic field has...

  9. Static Calibration of Tactical Grade Inertial Measurement Units

    Hayal, Adem G.
    The demand for precise positioning grows up parallel to the advances in production of the geolocation instruments. Today, the Global Positioning System (GPS) is the most common positioning system in use because of its being very precise, convenient and cheap. However, when working in such areas that the external references (e.g. GPS satellites) are not available, a system that does not require information from any external source of information is required. Especially, these kinds of systems necessitate in detection of unexploded ordnances (UXO) buried in forestry areas, where precise position information is vital for removing them. The Inertial Navigation System (INS) operates in any environment and does not...

  10. Heights, the Geopotential, and Vertical Datums

    Jekeli, Christopher
    This report reviews the fundamental definitions of heights and vertical datums, specifically motivated by the modern technique of determining heights using accurate satellite vertical positioning in combination with an accurate model for the geopotential. It is shown that the determination of heights in such a manner requires knowledge of the potential value of the vertical datum (as opposed to leveling procedures that do not require this). Furthermore, to determine the potential of a vertical datum ideally requires normal heights (defined at the origin point of the datum, or determined elsewhere by leveling) rather than orthometric heights, as this avoids the complication of assuming a density model for...

  11. Direct Sensor Orientation in Airborne and Land-based Mapping Applications

    Grejner-Brzezinska, Dorota A.
    Since the early 1990s, the concept of Mobile Mapping Systems (MMS) has evolved from rather simple land-based systems to more sophisticated, real-time multi-tasking and multi-sensor systems, operational in land and airborne environments. Mobile Mapping technology has made a remarkable progress, notably expanding its use in remote sensing, and surveying and mapping markets. New systems are being developed and built for specialized applications, in support of land-based and airborne imaging sensors, aimed at automatic data acquisition for GIS databases. The major objective of this report is to review the concept of Mobile Mapping System and GPS/INS supported direct platform orientation (DPO) in particular, as well as their evolution since...

  12. Object Recognition from AIMS Data Using Neural Networks

    Li, Ron; Ma, Fei; Tu, Zhuowen
    Project Report (November 1997 – December 1998). Submitted to The OSU Center For Mapping.

  13. Gravity Recovery Using COSMIC GPS Data: Application of Orbital Perturbation Theory

    Hwang, Cheinway
    COSMIC is a joint Taiwan-US mission to study atmosphere using GPS occultation. Its GPS data for precise orbit determination can be used for gravity recovery. In this report a kinematic approach was employed which assumes the positional data can be derived from the GPS data of COSMIC in the operational phase. Using the geometric relationship between the positional variations of orbit and the variations in the six Keplerian elements, improved formulae for the radial, along-track and cross-track perturbations were derived. Based on a comparison with true perturbations from numerical integrations, these formulae are more accurate than the commonly used order-zero formulae. The improved formulae were used to...

  14. Coastal Altimetry and Applications

    Anzenhofer, Michael; Shum, C. K.; Rentsh, Mathias
    This report was prepared by Dr. Michael Anzenhofer of the Geo-Forschungs-Zentrum (GFZ) Potsdam, Germany, while visiting the Department of Civil and Environmental Engineering and Geodetic Science (CEEGS), Ohio State University, during 1997-1998. The visit was hosted by Prof. C.K. Shum of the Department of Civil and Environmental Engineering and Geodetic Science.

  15. Applications of Parameter Estimation and Hypothesis Testing to GPS Network Adjustments

    Snow, Kyle Brian
    It is common in geodetic and surveying network adjustments to treat the rank deficient normal equations in a way that produces zero variances for the so–called "control" points. This is often done by placing constraints on a minimum number of the unknown parameters, typically by assigning a zero variance to the a priori values of these parameters (coordinates). This approach may require the geodetic engineer or analyst to make an arbitrary decision about which parameters to constrain, which may have undesirable effects, such as parameter error ellipses that grow with distance from the constrained point. Constraining parameters to a priori values is...

  16. Statistical Analysis of Moving-Base Gravimetry and Gravity Gradiometry

    Jekeli, Christopher
    Moving-base gravimetry systems require multiple sensors to extract the gravitational signal – an accelerometer (or gravimeter), or a set of mutually orthogonal accelerometers that sense the action forces on the vehicle; a suite of gyroscopes (or a stabilized platform) that provides proper orientation for the accelerometers; and a geometric (kinematic) positioning system (e.g., GPS) from which the kinematic acceleration may be derived, and that also provides geospatial referencing of the signals. The error in the recovered gravitational signal depends on the individual sensor errors, but also on the coupling of the sensor errors to the actual acceleration environment of the system. The error analysis is fairly well...

  17. Efficient Global Gravity Determination from Satellite-to-Satellite Tracking (SST)

    Han, Shin-Chan
    By the middle of this decade, measurements from the CHAMP (CHAllenging of Minisatellite Payload) and GRACE (Gravity Recovery And Climate Experiment) gravity mapping satellite missions are expected to provide a significant improvement in our knowledge of the Earth's mean gravity field and its temporal variation. For this research, new observation equations and efficient inversion method were developed and implemented for determination of the Earth’s global gravity field using satellite measurements. On the basis of the energy conservation principle, in situ (on-orbit) and along track disturbing potential and potential difference observations were computed using data from accelerometer- and GPS receiver-equipped satellites, such as CHAMP and GRACE. The efficient iterative...

  18. Local and Regional Geoid Determination from Vector Airborne Gravimetry

    Serpas, Juan Gilberto, 1959-
    The local geoid in a test area in the Canadian Rocky Mountains is computed using airborne gravimetry data. The geoid is computed by the use of the vertical and horizontal components (VC and HC) of the gravity disturbance vector. In addition, an attempt to combine the three components by the use of least squares collocation is done. The technique of using crossovers to estimate for biases and trends in the gravity signals and the use of minimal control in the form of constraints in the crossover adjustment are studied. Moreover, the downward continuation as well as the direct and indirect effects due to removal and restoration of...

  19. Radar Altimeter Absolute Calibration Using GPS Water Level Measurements

    Cheng, Kai-chien, 1969-
    Recent studies of using long-term island and coastal tide gauges (over 60 years) indicate that the global sea level rise is at a rate of 1.8 to 1.9 ± 0.1 mm/year (e.g., Douglas 1997, 1991; Trupin and Wahr, 1990; Warrick and Oerlemans, 1990). Satellite radar altimetry has evolved into a tool for synoptic observation of the global (±81.5° latitude) oceanic phenomena with unprecedented accuracy (several cm in sea surface height) and with a temporal resolution of 1-2 weeks and a spatial resolution of 50 km. Its accuracy, global coverage, and temporal resolution enable its use in studies of global sea level changes. With accurate links among different...

  20. GPS Buoy Campaigns for Vertical Datum Improvement and Radar Altimeter Calibration

    Cheng, Kai-chien
    This report summarized three Global Positioning System (GPS) buoy campaigns in the Great Lakes from 1999 to 2003 that were carried out by the Laboratory of Space Geodesy and Remote Sensing Research in the Department of Civil and Environmental Engineering and Geodetic Science (CEEGS), at the Ohio State University. The report focuses on the field work procedure of GPS buoy operation in these past campaigns and is intended to provide experience for similar applications in the future. The campaigns in this report include the Holland Campaign in Lake Michigan in 1999, the Marblehead Campaign in Lake Erie in 2001, and the Cleveland Campaign in Lake Erie in 2003....

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