2016 Data collected for Resistivity, Magnetic Susceptibility and Sediment Characterization of the York River Estuary, VA in Support of the Empirical Investigation of the Factors Influencing Marine Applications of EMI (Year 2 of SERDP Project MR-2409)

The objective of this component of the Strategic Environmental Research and Development Program (SERDP) Project MR-2409 was to conduct field measurements to aid in the determination of the electromagnetic induction (EMI) response to the water column and underlying sediments in the York River estuary, which includes water column and sediment properties similar to many underwater environments of interest to unexploded ordinance detection. Data and samples from a standard suite of hydrographic and sedimentological measurements, as well as electrical resistivity and magnetic susceptibility, were collected and analyzed for each location. These cruises provided opportunities to obtain information that is being used to quantify the unique marine contributions to the early time TEM noise, including conductivity variations in the water and variability in bottom sediment properties in real marine environments, for use in the parallel modeling and electromagnetic-induction sensor work ongoing in the same project. Data collected during Year 1 (2014) of this project were used to select the appropriate locations to provide a range of conductivity and sediment conditions. This work was used to choose appropriate locations during Year 2 (2016) of this project, described in this report, to field-test the EMI sensor arrays. (Note that there was a delay of several months between the end of Year 1 work and the start of Year 2 work. Thus the Year 2 final report is dated more than 12 months after the Year 1 final report.

Assessment of Multispectral Imaging System for UAS Navigation in a GPS-denied Environment

NPS NRP Executive SummaryMultispectral (MS) imaging systems have been used for the detection, identification, and quantification in numerous environmental and military applications already. It is proposed to analyze feasibility of utilizing this emerging technology on small unmanned aerial vehicles (sUAS) for the purpose of enhancing accuracy and precision of object detection (identification), classification and tracking (DCT) that may contribute to a variety of downstream applications including threat detection, forensics, battle damage-assessment, additional/alternative aid to navigation (ATON) in the GPS-degraded or GPS-denied environments. This study assesses applicability and benefits of using a MS sensor as opposed to standard infrared (IR) and/or electro-optical (EO) sensors for DCT applications. It also includes an assessment of the computer-vision (CV) and artificial intelligence (AI) algorithms to quickly and reliably process the sensor output data. It is envisioned that a MicaSense RedEdge-MX or Altum like high-resolution global-shutter 5-band MS sensor integrated with a commercial-of-the-shelf (COTS) Group 1 or Group2 sUAS will be used to collect data to train a deep-learning (DL) convolutional neural network (DCNN) capable to handle one or two specific DCT problems to address the following research questions: Whether using multiple spectral bands has any benefits compared to a standard EO sensor or EO sensor combined with IR sensor? That includes benefits of having a spectral profile of surrounding background area and objects from the standpoint of more reliable/precise DCT. What are the limitations of using MS sensors and CV/AI algorithms to process data from the standpoint of operating environment, terrain, altitudes, object size and material, time of the day, weather, number of spectral bands, resolution, narrow field of view, addition of a downwelling light sensor)? What computational resources would be required to enable DTS capability aboard COTS sUAS The study will look at the requirements to such a system and its CONOPS, followed by conducting numerical experiments and field testing to gather and analyze data coming out of a MS imaging sensor. It is expected to involve SE, OC and CS students, and summarize all the findings in the final report.Naval Special Warfare Command (NAVSPECWARCOM)N9 - Warfare SystemsThis research is supported by funding from the Naval Postgraduate School, Naval Research Program (PE 0605853N/2098). https://nps.edu/nrpChief of Naval Operations (CNO)Approved for public release. Distribution is unlimited.

Pulsed operation of a miniature scalar optically-pumped magnetometer

A scalar magnetic field sensor based on a millimeter-size 87 Rb vapor cell is described. The magnetometer uses nearly copropagating pump and probe laser beams, amplitude modulation of the pump beam, and detection through monitoring the polarization rotation of the detuned probe beam. The circularly polarized pump laser resonantly drives a spin precession in the alkali atoms at the Larmor frequency. A modulation signal on the probe laser polarization is detected with a lock-in amplifier. Since the Larmor precession is driven all-optically, potential cross talk between sensors is minimized. And since the pump light is turned off during most of the precession cycle, large offsets of the resonance, typically present in a single-beam Bell&ndash;Bloom scheme, are avoided. At the same time, relatively high sensitivities can be reached even in millimeter-size vapor cells: The magnetometer achieves a sensitivity of 1 pT/Hz 1/2 in a sensitive volume of 16 mm 3 , limited by environmental noise. When a gradiometer configuration is used to cancel the environmental noise, the magnetometer sensitivity reaches 300 fT/Hz 1/2 . We systematically study the dependence of the magnetometer performance on the optical duty cycles of the pump light and find that better performance is achieved with shorter duty cycles, with the highest values measured at 1.25% duty cycle.</p

Resistivity, Magnetic Susceptibility and Sediment Characterization of the York River Estuary in Support of the Empirical Investigation of the Factors Influencing Marine Applications of EMI (Year 2 of SERDP Project MR-2409) Final Report.

Vessel and personnel support was provided for a series of cruises to three salinity regimes along the York River. Data and samples from a standard suite of hydrographic and sedimentological measurements, as well as electrical resistivity and magnetic susceptibility, were collected and analyzed for each location. These cruises provided opportunities to obtain information that is being used to quantify the unique marine contributions to the early time TEM noise, including conductivity variations in the water and variability in bottom sediment properties in real marine environments, for use in the parallel modeling and electromagnetic-induction sensor work ongoing in the same project. Data collected during Year 1 of this project were used to select the appropriate locations to provide a range of conductivity and sediment conditions

Wideband harmonic radar detection

Radio sites consist naturally of metallic structures. Metals are always covered by an oxide film due to the metal reacting chemically with the oxygen in air. The rate of this oxide formation depends largely on the environment. Any oxide film between metallic contacts will cause non-linearity. RF currents passing through these junctions would generate harmonics. When RF signals at two frequencies fl and f2 pass-through a non-linearity they create signals at their sum and difference frequencies. These are known as 'inter-modulation products'. This generation of inter-modulation products when radio waves interact with rusty parts is called as the 'Rusty Bolt Effect'. Radio spectrum is carefully controlled for optimal usage of the available frequencies so that different services operate in well-defined frequency channels. Ofcom has set some standards for radio site engineering. This set of standards is given in the document 'MPT 1331: Code of Practice for Radio Site Engineering'. Any transmission site which is not following these codes would likely cause interference to other users. It is important that radio engineers should check the sites for their compliance with these codes. If a particular radio site is causing interference due to the rusty-bolt effect, the corroded points must be located to minimize their effect using a Harmonic Radar. A 'Harmonic Radar' is a device that illuminates a region of space with RF waves and receives the harmonics of the transmitted frequencies. The received data can then be processed to find the exact location and mobility of the points causing the generation of these harmonics. It works on the principle of radar transmitting a chirp signal and receiving harmonics of the transmitting frequency. Work is currently being carried out at the 'Centre for Communication Systems' in Durham University funded by HMGCC on the design and implementation of a novel Wideband Harmonic Radar system. The radar system would employ advanced sub-systems i.e. a suitable waveform and multiple antenna arrays processing super-resolution algorithms for angular information

Polarization-dependent wavelength-selective structures for multispectral polarimetric infrared imaging

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2007.Includes bibliographical references (p. 173-181).The need for compact, rugged, low-cost multispectral-polarimetric filtering technology exists in both the civilian and defense communities. Such technology can be used for object detection, object recognition, and image contrast enhancement. Mosaicked multispectral-polarimetric filter technology, using CMOS-type metallo-dielectric grating structures, is presented as a potential solution in which the spectral filtering and polarization filtering functions are performed in a single component. In this work, single-layer and double-layer metallic-grating structures, embedded in uniform dielectric are investigated. Spectral tunability using only transverse grating properties in a two-layer metallic-grating structure is demonstrated. Additionally, one-layer and two-layer slotted-grid rectangular-aperture two-dimensional metallic gratings for infrared imaging are also studied. To complement the simulations, thirty-nine separate infrared optical polarization and spectral filters were fabricated in silicon using the AMI 0.5pm / MOSIS foundry service, and they were characterized using polarized FTIR analysis. Polarized transmission spectra from these CMOS-based filters compare favorably with simulation results for four of the most promising filter types. An external-cavity-coupled single-layer metallic-grating structure, compatible with CMOS microbolometer detector technology is also offered as an application example.by David R. Dunmeyer.Ph.D

Holistic Inversion of Airborne Electromagnetic Data

A holistic method for simultaneously calibrating, processing, and inverting frequency-domain airborne electromagnetic data has been developed. A spline-based, 3D, layered conductivity model covering a complete survey area is recovered through inversion of an entire raw airborne data set and available independent geoelectric and interface-depth data. The holistic inversion formulation includes a mathematical model to account for systematic calibration errors such as incorrect gain, phase and zero-level. By taking these elements into account in the inversion, the need to pre-process the airborne data prior to inversion is eliminated. Conventional processing schemes involve the sequential application of a number of calibration corrections, with data from each frequency being treated separately. This is followed by inversion of each multi-frequency airborne sample in isolation from other samples. By simultaneously considering all of the available information in a holistic inversion, the inter-frequency and spatial coherency characteristics of the data are able to be exploited. The formulation ensures that the conductivity and calibration models are optimal with respect to the airborne data and prior information. Introduction of inter-frequency inconsistency and multistage error propagation stemming from the sequential nature of conventional processing schemes is also avoided. It is confirmed that accurate conductivity and calibration parameter values are recovered from holistic inversion of synthetic data sets. It is also demonstrated that the results from holistic inversion of raw survey data are superior to the output of conventional 1D inversion of final processed contractor delivered data. In addition to the technical benefits, it is expected that holistic inversion will reduce costs by avoiding the expensive calibration→processing→recalibration paradigm. Furthermore, savings may also be made because specific high altitude zero-level observations, needed for conventional processing, may not be required. The same philosophy is also applied to the inversion of time-domain data acquired by fixed-wing towed-bird systems. A spline-based, 2D, layered conductivity model covering a complete survey line is recovered along with a calibrations model. In this instance, the calibration model is a spline based representation of three unmeasured elements of the system geometry. By inverting the less processed total field data, the procedure is able to prevent incorrect assumptions made in conventional primary field removal from being propagated into the inversion stage. Furthermore, by inverting a complete line of data at once the along-line spatial coherency of the geology and the geometry variations is exploited. Using real survey data, it was demonstrated that all components of the data could be simultaneously and satisfactorily fitted and that the resulting conductivity model was consistent with independent prior information. This was an improvement over the conventional approach, in which the data could not be satisfactorily fitted, nor was the conductivity model consistent with prior information. It was further established that by using the holistic inversion spline parameterization, the resulting conductivity model was more continuous and interpretable than if the conventional style discrete parameterization was used. If adopted, the holistic approach, could reduce survey costs, reduce data processing turnaround times, and improve the quantitative information that can be extracted from data, and hence, increase the value of airborne electromagnetics for mineral exploration and environmental mapping applications.Geoscience Australi

Naval Research Program 2021 Annual Report

NPS NRP Annual ReportThe Naval Postgraduate School (NPS) Naval Research Program (NRP) is funded by the Chief of Naval Operations and supports research projects for the Navy and Marine Corps. The NPS NRP serves as a launch-point for new initiatives which posture naval forces to meet current and future operational warfighter challenges. NRP research projects are led by individual research teams that conduct research and through which NPS expertise is developed and maintained. The primary mechanism for obtaining NPS NRP support is through participation at NPS Naval Research Working Group (NRWG) meetings that bring together fleet topic sponsors, NPS faculty members, and students to discuss potential research topics and initiatives.Chief of Naval Operations (CNO)Approved for public release. Distribution is unlimited.

Laboratory Directed Research and Development Program FY 2004 Annual Report

The Oak Ridge National Laboratory (ORNL) Laboratory Directed Research and Development (LDRD) Program reports its status to the U.S. Department of Energy (DOE) in March of each year. The program operates under the authority of DOE Order 413.2A, 'Laboratory Directed Research and Development' (January 8, 2001), which establishes DOE's requirements for the program while providing the Laboratory Director broad flexibility for program implementation. LDRD funds are obtained through a charge to all Laboratory programs. This report describes all ORNL LDRD research activities supported during FY 2004 and includes final reports for completed projects and shorter progress reports for projects that were active, but not completed, during this period. The FY 2004 ORNL LDRD Self-Assessment (ORNL/PPA-2005/2) provides financial data about the FY 2004 projects and an internal evaluation of the program's management process. ORNL is a DOE multiprogram science, technology, and energy laboratory with distinctive capabilities in materials science and engineering, neutron science and technology, energy production and end-use technologies, biological and environmental science, and scientific computing. With these capabilities ORNL conducts basic and applied research and development (R&amp;D) to support DOE's overarching national security mission, which encompasses science, energy resources, environmental quality, and national nuclear security. As a national resource, the Laboratory also applies its capabilities and skills to the specific needs of other federal agencies and customers through the DOE Work For Others (WFO) program. Information about the Laboratory and its programs is available on the Internet at &lt;http://www.ornl.gov/&gt;. LDRD is a relatively small but vital DOE program that allows ORNL, as well as other multiprogram DOE laboratories, to select a limited number of R&amp;D projects for the purpose of: (1) maintaining the scientific and technical vitality of the Laboratory; (2) enhancing the Laboratory's ability to address future DOE missions; (3) fostering creativity and stimulating exploration of forefront science and technology; (4) serving as a proving ground for new research; and (5) supporting high-risk, potentially high-value R&amp;D. Through LDRD the Laboratory is able to improve its distinctive capabilities and enhance its ability to conduct cutting-edge R&amp;D for its DOE and WFO sponsors. To meet the LDRD objectives and fulfill the particular needs of the Laboratory, ORNL has established a program with two components: the Director's R&amp;D Fund and the Seed Money Fund. As outlined in Table 1, these two funds are complementary. The Director's R&amp;D Fund develops new capabilities in support of the Laboratory initiatives, while the Seed Money Fund is open to all innovative ideas that have the potential for enhancing the Laboratory's core scientific and technical competencies. Provision for multiple routes of access to ORNL LDRD funds maximizes the likelihood that novel and seminal ideas with scientific and technological merit will be recognized and supported