Theory and measure of certain image norms in SAR

The principal properties of synthetic aperture radar SAR imagery of point and distributed objects are summarized. Against this background, the response of a SAR (Synthetic Aperture Radar) to the moving surface of the sea is considered. Certain conclusions are drawn as to the mechanism of interaction between microwaves and the sea surface. Focus and speckle spectral tests may be used on selected SAR imagery for areas of the ocean. The fine structure of the sea imagery is sensitive to processor focus and adjustment. The ocean reflectivity mechanism must include point like scatterers of sufficient radar cross section to dominate the return from certain individual resolution elements. Both specular and diffuse scattering mechanisms are observed together, to varying degree. The effect is sea state dependent. Several experiments are proposed based on imaging theory that could assist in the investigation of reflectivity mechanisms

An alternative multi-mode SAR for RADARSAT

The RADARSAT project was asked by the Canadian government in the spring of 1986 to design for reduced costs and increased radar performance as compared to the well-known baseline design. Both the Project Office and Canadian industry (lead by SPAR Aerospace of Montreal) have undertaken to meet this request, with a proposal to cabinet to be submitted in the fall of 1986. One alternative SAR concept is outlined which is under consideration for a revised RADARSAT configuration. The radar system described uses two frequencies (C&L band) over four possible modes: near range swath; far range swath; wide swath; and high resolution. Good sensitivity, resolution, and coverage are obtained with modest power and data rates. The antenna systems are relatively simple. Indeed, no break-through technological developments are needed. The design allows several mode combinations for simultaneous data collection or performance enhancement. The principal parameters are described. A nominal mean altitude of 700 km is assumed

A solution to the problem of SAR range curvature

When synthetic aperture radar systems are pushed to attain finer resolution at larger ranges than was previously the case for remote sensing purposes, the geometric signal aberration known as range curvature arises. Known techniques for correcting range curvature are exact at only one selected range, thus forcing neighboring ranges to use the same correction as an approximation. A solution to the problem is proposed that is exact at all ranges, thus simplifying and improving the image processing for such systems

Detection of Radial Bolt-Hole Cracks Using Sampled CW Ultrasonic Doppler-Shift Techniques

Recently there has been considerable interest in detecting radial cracks under fasteners in the wings of C-5A aircraft. Generally, detection is accomplished using the pulse-echo method, reflections from cracks being detected in real time. In the present study, cracks are detected by observing the ·Doppler-shifted frequency. A sample having a radial crack is mounted on a rotating platform in a water bath. A focused transducer transmits a tone burst such that only the shear mode propagates tangential to the hole in the metal. This transducer receives a Doppler-shifted reflected signal whenever a moving crack is in the field of view of the incident beam. The received signal is heterodyned, filtered, and displayed on a low-frequency spectrum analyzer. Merits and limitations of the technique are discussed

Joint Strong and Weak Lensing Analysis of the Massive Cluster Field J0850+3604

We present a combined strong and weak lensing analysis of the J085007.6+360428 (J0850) field, which was selected by its high projected concentration of luminous red galaxies and contains the massive cluster Zwicky 1953. Using Subaru/Suprime-Cam $BVR_{c}I_{c}i^{\prime}z^{\prime}$ imaging and MMT/Hectospec spectroscopy, we first perform a weak lensing shear analysis to constrain the mass distribution in this field, including the cluster at $z = 0.3774$ and a smaller foreground halo at $z = 0.2713$. We then add a strong lensing constraint from a multiply-imaged galaxy in the imaging data with a photometric redshift of $z \approx 5.03$. Unlike previous cluster-scale lens analyses, our technique accounts for the full three-dimensional mass structure in the beam, including galaxies along the line of sight. In contrast with past cluster analyses that use only lensed image positions as constraints, we use the full surface brightness distribution of the images. This method predicts that the source galaxy crosses a lensing caustic such that one image is a highly-magnified "fold arc", which could be used to probe the source galaxy's structure at ultra-high spatial resolution ($< 30$ pc). We calculate the mass of the primary cluster to be $\mathrm{M_{vir}} = 2.93_{-0.65}^{+0.71} \times 10^{15}~\mathrm{M_{\odot}}$ with a concentration of $\mathrm{c_{vir}} = 3.46_{-0.59}^{+0.70}$, consistent with the mass-concentration relation of massive clusters at a similar redshift. The large mass of this cluster makes J0850 an excellent field for leveraging lensing magnification to search for high-redshift galaxies, competitive with and complementary to that of well-studied clusters such as the HST Frontier Fields.Comment: Accepted for publication in The Astrophysical Journal; 14 pages, 13 figures, 3 table

Theory of synthetic aperture radar ocean imaging: A MARSEN view

This paper reviews basic synthetic aperture radar (SAR) theory of ocean wave imaging mechanisms, using both known work and recent experimental and theoretical results from the Marine Remote Sensing (MARSEN) Experiment. Several viewpoints that have contributed to the field are drawn together in a general analysis of the backscatter statistics of a moving sea surface. A common focus for different scattering models is provided by the mean image impulse response function, which is shown to be identical to the (spatially varying) frequency variance spectrum of the local complex reflectivity coefficient. From the analysis has emerged a more complete view of the SAR imaging phenomenon than has been previously available. A new, generalized imaging model is proposed

Interactions of ingested food, beverage, and tobacco components involving human cytochrome P4501A2, 2A6, 2E1, and 3A4 enzymes.

Human cytochrome P450 (P450) enzymes are involved in the oxidation of natural products found in foods, beverages, and tobacco products and their catalytic activities can also be modulated by components of the materials. The microsomal activation of aflatoxin B1 to the exo-8,9-epoxide is stimulated by flavone and 7,8-benzoflavone, and attenuated by the flavonoid naringenin, a major component of grapefruit. P4502E1 has been demonstrated to play a potentially major role in the activation of a number of very low-molecular weight cancer suspects, including ethyl carbamate (urethan), which is present in alcoholic beverages and particularly stone brandies. The enzyme (P4502E1) is also known to be inducible by ethanol. Tobacco contains a large number of potential carcinogens. In human liver microsomes a significant role for P4501A2 can be demonstrated in the activation of cigarette smoke condensate. Some of the genotoxicity may be due to arylamines. P4501A2 is also inhibited by components of crude cigarette smoke condensate. The tobacco-specific nitrosamines are activated by a number of P450 enzymes. Of those known to be present in human liver, P4501A2, 2A6, and 2E1 can activate these nitrosamines to genotoxic products

Listening to ironically-enjoyed music: A self-regulatory perspective

This research examines adults’ reported motivations for listening to music that they enjoy ironically. In a pilot (N = 96) and main (N = 175) studies, open-ended responses from adults were analysed using Thematic Analysis. Based on the pilot study, ironically enjoyed music was defined as “Music that is enjoyed because of being bad, despite being bad, or for different reasons than intended.” Although many relevant self-regulatory functions of listening to music in general were also relevant to ironically- enjoyed music, it also emerged that ironic enjoyment of music has characteristics that are unique to it: the additional role of mocking, ridiculing, and laughing at the music, and the social benefit that this provides. Music that was listened to “because of” its negative features had a variety of musical features, and the listening usually served functions unique to ironic enjoyment of music, such as mockery. When music was listened to “despite” negative qualities, the music itself was often described as having attractive rhythm, melody or lyrics, while the irony protected the listener from conflicting values associated with the music, helping the listener communicate to others that they did not identify with the music on a higher level. Unfamiliar music mainly played a social role, whereas familiar music related to nostalgia as well as most other functions