Effects of surface randomness of radar backscatter from a spherical surface

Approximation solution to integral expressions of radar backscatter from distant rough surfaces for lunar surface property determinatio

Reflection and transmission of dipole radiation in presence of an extended boundary, rough and smooth

Reflection and transmission of dipole radiation with rough or smooth boundarie

<investigation of radar echoes from the moon planets, using methods and data from earth radar-return studies< semiannual status report, 1 nov. 1964 - 30 apr. 1965

Differential reflectivity for estimating surface properties of reflecting body - radar signal reflectio

Investigation of radar echoes from the moon and planets, using methods and data from earth radar-return studies Semiannual status report, 1 May - 31 Oct. 1965

Monostatic reflection from statistically rough sphere, electromagnetic properties of smooth sphere from bistatic power measurement, and acoustic differential reflectivity developmen

Analysis of waveguiding properties of VCSEL structures

In this paper, the authors explore the feasibility of using the distributed Bragg reflector, grown on the substrate for a VCSEL (Vertical Cavity Surface Emitting Laser), to provide waveguiding within the substrate. This waveguiding could serve as an interconnection among VCSELs in an array. Before determining the feasibility of waveguide interconnected VCSELs, two analysis methods are presented and evaluated for their applicability to this problem. The implementations in Mathematica of both these methods are included. Results of the analysis show that waveguiding in VCSEL structures is feasible. Some of the many possible uses of waveguide interconnected VCSELs are also briefly discussed. The tools and analysis presented in this report can be used to evaluate such system concepts and to do detailed design calculations

A novel algorithm for real-time adaptive signal detection and identification

This paper describes a novel digital signal processing algorithm for adaptively detecting and identifying signals buried in noise. The algorithm continually computes and updates the long-term statistics and spectral characteristics of the background noise. Using this noise model, a set of adaptive thresholds and matched digital filters are implemented to enhance and detect signals that are buried in the noise. The algorithm furthermore automatically suppresses coherent noise sources and adapts to time-varying signal conditions. Signal detection is performed in both the time-domain and the frequency-domain, thereby permitting the detection of both broad-band transients and narrow-band signals. The detection algorithm also provides for the computation of important signal features such as amplitude, timing, and phase information. Signal identification is achieved through a combination of frequency-domain template matching and spectral peak picking. The algorithm described herein is well suited for real-time implementation on digital signal processing hardware. This paper presents the theory of the adaptive algorithm, provides an algorithmic block diagram, and demonstrate its implementation and performance with real-world data. The computational efficiency of the algorithm is demonstrated through benchmarks on specific DSP hardware. The applications for this algorithm, which range from vibration analysis to real-time image processing, are also discussed

Case study: Unattended ground sensor phenomenology and signal processing

In the fall of 1995, a unique unattended ground sensor experiment was conducted at the Nevada Test Site. In the experiment, a variety of electro-mechanical equipment was operated, while data was gathered using a number of different types of unattended sensors at different locations. The sensors in this study included seismometers, accelerometers, electric dipole sensors, magnetometers and microphones. In this paper, the authors present some key results form the signal processing of the data from this experiment. The goal of the signal processing was to quantify some of the effects of range on signal propagation, and to determine the ability to detect signals from the equipment, to identify the equipment and to locate the equipment. Some of the physical phenomenon which can affect unattended ground sensor performance will be discussed. The paper will also include a discussion of how the geophysical site characteristics can affect the performance of unattended ground-deployed sensors. While data from a number of different types of sensors were gathered in this experiment, in this paper the authors concentrate on physical phenomenon which can affect seismic sensors and the processing of seismic data

Evaluation of the applicability of existing nuclear power plant regulatory requirements in the U.S. to advanced small modular reactors.

The current wave of small modular reactor (SMR) designs all have the goal of reducing the cost of management and operations. By optimizing the system, the goal is to make these power plants safer, cheaper to operate and maintain, and more secure. In particular, the reduction in plant staffing can result in significant cost savings. The introduction of advanced reactor designs and increased use of advanced automation technologies in existing nuclear power plants will likely change the roles, responsibilities, composition, and size of the crews required to control plant operations. Similarly, certain security staffing requirements for traditional operational nuclear power plants may not be appropriate or necessary for SMRs due to the simpler, safer and more automated design characteristics of SMRs. As a first step in a process to identify where regulatory requirements may be met with reduced staffing and therefore lower cost, this report identifies the regulatory requirements and associated guidance utilized in the licensing of existing reactors. The potential applicability of these regulations to advanced SMR designs is identified taking into account the unique features of these types of reactors

Frequency response of a TeO{sub 2} slow shear wave acousto-optic cell exposed to radiation

Radiation testing of photonic components is not new, however component level testing to date has not completely addressed quantities which are important to system behavior. One characteristic that is of particular importance for optical processing systems is the frequency response. In this paper, the authors present the results of the analysis of data from an experiment designed to provide a preliminary understanding of the effects of radiation on the frequency response of acousto-optic devices. The goal is to present possible physical mechanisms responsible for the radiation effects and to discuss the effects on signal processing functionality. The experiment discussed in this paper was designed by Sandia National Laboratories (SNL) and performed by SNL and Phillips Laboratory (PL) personnel at White Sands Missile Range (WSMR). In the experiment, a TeO{sub 2} slow shear-wave acousto-optic cell was exposed to radiation from the WSMR linear accelerator. The TeO{sub 2} cell was placed in an experimental configuration which allowed swept frequency diffracted power measurements to be taken during radiation exposure and recovery. A series of exposures was performed. Each exposure consisted of between 1 to 800, 1 {mu}sec radiation pulses (yielding exposures of 2.25 kRad(Si) to 913 kRad(Si)), followed by recovery time. At low total and cumulative doses, the bandshape of the frequency response (i.e. diffracted power vs. frequency) remained almost identical during and after radiation. At the higher exposures, however, the amplitude and width of the frequency response changed as the radiation continued, but returned to the original shape slowly after the radiation stopped and recovery proceeded. It is interesting to note that the location of the Bragg degeneracy does not change significantly with radiation. In this paper, the authors discuss these effects, and they discuss the effect on the signal processing functionality

Electromagnetic field representation in inhomogeneous anisotropic media

Some of the basic developments in the theory of electromagnetic field representation in terms of Hertz vectors are reviewed. A solution for the field in an inhomogeneous anisotropic medium is given in terms of the two Hertz vectors. Conditions for presentation of the field in terms of uncoupled transverse electric and transverse magnetic modes, in a general orthogonal coordinate system, are derived when the permeability and permittivity tensors have only diagonal components. These conditions are compared with some known special cases.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/47031/1/339_2004_Article_BF00883972.pd