Three-dimensional attitude determination strategy fused polarized light and geomagnetism

2021 ◽  
Author(s):  
Shan Li ◽  
Donghua Zhao ◽  
Hua Yu ◽  
Tao Jin ◽  
Chenguang Wang ◽  
...  
Keyword(s):  
Attitude Determination ◽  
Three Dimensional ◽  
Polarized Light

scholarly journals Mass-resolved electronic circular dichroism ion spectroscopy

Science ◽  
2020 ◽  
Vol 368 (6498) ◽  
pp. 1465-1468 ◽  
Author(s):  
Steven Daly ◽  
Frédéric Rosu ◽  
Valérie Gabelica
Keyword(s):  
Circular Dichroism ◽  
Three Dimensional ◽  
Polarized Light ◽  
Negative Ions ◽  
Data Interpretation ◽  
Electronic Circular Dichroism ◽  
Circularly Polarized Light ◽  
Chiral Compounds ◽  
Electron Photodetachment ◽  
Circular Dichroïsm

DNA and proteins are chiral: Their three-dimensional structures cannot be superimposed with their mirror images. Circular dichroism spectroscopy is widely used to characterize chiral compounds, but data interpretation is difficult in the case of mixtures. We recorded the electronic circular dichroism spectra of DNA helices separated in a mass spectrometer. We studied guanine-rich strands having various secondary structures, electrosprayed them as negative ions, irradiated them with an ultraviolet nanosecond optical parametric oscillator laser, and measured the difference in electron photodetachment efficiency between left and right circularly polarized light. The reconstructed circular dichroism ion spectra resembled those of their solution-phase counterparts, thereby allowing us to assign the DNA helical topology. The ability to measure circular dichroism directly on biomolecular ions expands the capabilities of mass spectrometry for structural analysis.

scholarly journals Polarization-sensitive photodetectors based on three-dimensional molybdenum disulfide (MoS2) field-effect transistors

Nanophotonics ◽  
2020 ◽  
Vol 9 (16) ◽  
pp. 4719-4728
Author(s):  
Tao Deng ◽  
Shasha Li ◽  
Yuning Li ◽  
Yang Zhang ◽  
Jingye Sun ◽  
...  
Keyword(s):  
Molybdenum Disulfide ◽  
Field Effect ◽  
High Performance ◽  
Field Effect Transistors ◽  
Three Dimensional ◽  
Polarized Light ◽  
Optical Field ◽  
Two Dimensional ◽  
Polarization Ratio ◽  
Two Dimensional Materials

AbstractThe molybdenum disulfide (MoS2)-based photodetectors are facing two challenges: the insensitivity to polarized light and the low photoresponsivity. Herein, three-dimensional (3D) field-effect transistors (FETs) based on monolayer MoS2 were fabricated by applying a self–rolled-up technique. The unique microtubular structure makes 3D MoS2 FETs become polarization sensitive. Moreover, the microtubular structure not only offers a natural resonant microcavity to enhance the optical field inside but also increases the light-MoS2 interaction area, resulting in a higher photoresponsivity. Photoresponsivities as high as 23.8 and 2.9 A/W at 395 and 660 nm, respectively, and a comparable polarization ratio of 1.64 were obtained. The fabrication technique of the 3D MoS2 FET could be transferred to other two-dimensional materials, which is very promising for high-performance polarization-sensitive optical and optoelectronic applications.

Multivariate Constrained GNSS Real-time Full Attitude Determination Based on Attitude Domain Search

2018 ◽  
Vol 72 (2) ◽  
pp. 483-502
Author(s):  
Hongtao Wu ◽  
Xiubin Zhao ◽  
Chunlei Pang ◽  
Liang Zhang ◽  
Bo Feng
Keyword(s):  
Objective Function ◽  
Success Rate ◽  
High Efficiency ◽  
Attitude Determination ◽  
A Priori ◽  
Three Dimensional ◽  
Satellite System ◽  
New Method ◽  
Lambda Method ◽  
Attitude Angle

A priori attitude information can improve the success rate and reliability of Global Navigation Satellite System (GNSS) multi-antennae attitude determination. However, a priori attitude information is nonlinear, and integrating a priori information into the objective function rigorously will increase the complexity of an ambiguity domain search, such as the Multivariate Constrained-Least-squares Ambiguity Decorrelation Adjustment (MC-LAMBDA) method. In this paper, a new method based on attitude domain search is presented to make use of the a priori attitude angle information with high efficiency. First, the a priori information of pitch and roll is integrated into the search process to derive the analytic search step for attitude angle, and the integer candidates are determined by traversal search in the three-dimensional attitude domain. Then, the objective function is parameterised with Euler angles, and a non-iterative approximate method is utilised to simplify the iterative computation in calculating objective function values. Experimental results reveal that compared to the MC-LAMBDA method, our new method has the same success rate and reliability, but higher efficiency in making use of a priori attitude information.

Optics, Optical Methods, and Microscopy

2021 ◽  
pp. 345-407
Author(s):  
Kannan M. Krishnan
Keyword(s):  
Optical Microscopy ◽  
Polarization State ◽  
Three Dimensional ◽  
Polarized Light ◽  
Dark Field ◽  
Optical Methods ◽  
Transverse Waves ◽  
Dark Field Imaging ◽  
Propagation Of Light ◽  
Scanning Optical Microscopy

Propagation of light is described as the simple harmonic motion of transverse waves. Combining waves that propagate on orthogonal planes give rise to linear, elliptical, or spherical polarization, depending on their amplitudes and phase differences. Classical experiments of Huygens and Young demonstrated the principle of optical interference and diffraction. Generalization of Fraunhofer diffraction to scattering by a three-dimensional arrangement of atoms in crystals forms the basis of diffraction methods. Fresnel diffraction finds application in the design of zone plates for X-ray microscopy. Optical microscopy, with resolution given by the Rayleigh criterion to be approximately half the wavelength, works best when tailored to the optimal characteristics of the human eye (λ = 550 nm). Lenses suffer from spherical and chromatic aberrations, and astigmatism. Optical microscopes operate in bright-field, oblique, and dark-field imaging conditions, produce interference contrast, and can image with polarized light. Variants include confocal scanning optical microscopy (CSOM). Metallography, widely used to characterize microstructures, requires polished or chemically etched surfaces to provide optimal contrast. Finally, the polarization state of light reflected from the surface of a specimen is utilized in ellipsometry to obtain details of the optical properties and thickness of thin film materials.

Brief Organic Review

2016 ◽  
Author(s):  
Gary W. Morrow
Keyword(s):  
Functional Groups ◽  
Lewis Acids ◽  
Three Dimensional ◽  
Polarized Light ◽  
Mirror Image ◽  
Bond Line ◽  
Organic Chemical ◽  
Chemical Structures ◽  
Or Groups ◽  
Standard Formalism

In addition to simple hydrocarbon structures (alkanes, alkenes, alkynes, and aromatic systems) and alkyl groups (methyl, ethyl, propyl, isopropyl, etc.), this text assumes a familiarity with the most common functional groups associated with organic chemical structures and their basic reactivity patterns. Table 1.1 summarizes the names and structures of some of the more important functional groups we will be dealing with throughout the remainder of the book. It is important to remember that functional groups containing O or N with nonbonding electrons have an affinity for both protic and Lewis acids and are important participators in H-bonding. Groups containing a carbonyl (C=O) function are especially important, as these bonds are strongly polarized (δ+C=Oδ–), the C atom being electron deficient and the O atom electron excessive; this strong polarization is mainly responsible for the familiar reactivity patterns associated with carbonyl compounds. Figure 1.1 depicts the standard classification of isomers in organic chemical structures. Recall that constitutional isomers are compounds with the same molecular formula but different atom connectivity, such as 1-butanol versus 2-butanol. Stereoisomers, on the other hand, are compounds with the same formula and the same atom connectivity, differing from one another only in the three-dimensional orientation of their atoms in space. These are divided into two groups: enantiomers and diastereomers. Enantiomers are nonsuperimposable mirror image molecules whose asymmetry is usually the result of a tetrahedral carbon atom with four different atoms or groups attached to it, as in the 2-butanol enantiomers. Such chiral molecules rotate the plane of polarized light either (+) or (−) and so are said to be optically active. Achiral molecules, such as 1-butanol, do not rotate the plane of polarized light and so are optically inactive. A standard formalism for representation of a chiral center is to use bond line drawings with two of the four atoms or groups lying in the plane of the paper, a third projecting outward (wedge bond), and the fourth projecting inward (dashed bond).

A cortex-like canonical circuit in the avian forebrain

Science ◽  
2020 ◽  
Vol 369 (6511) ◽  
pp. eabc5534
Author(s):  
Martin Stacho ◽  
Christina Herold ◽  
Noemi Rook ◽  
Hermann Wagner ◽  
Markus Axer ◽  
...  
Keyword(s):  
Cerebral Cortex ◽  
Cognitive Skills ◽  
Three Dimensional ◽  
Polarized Light ◽  
Structural Basis ◽  
Fiber Architecture ◽  
Neuronal Circuitry ◽  
Mammalian Counterpart ◽  
Tracing Techniques ◽  
Neuronal Computation

Although the avian pallium seems to lack an organization akin to that of the cerebral cortex, birds exhibit extraordinary cognitive skills that are comparable to those of mammals. We analyzed the fiber architecture of the avian pallium with three-dimensional polarized light imaging and subsequently reconstructed local and associative pallial circuits with tracing techniques. We discovered an iteratively repeated, column-like neuronal circuitry across the layer-like nuclear boundaries of the hyperpallium and the sensory dorsal ventricular ridge. These circuits are connected to neighboring columns and, via tangential layer-like connections, to higher associative and motor areas. Our findings indicate that this avian canonical circuitry is similar to its mammalian counterpart and might constitute the structural basis of neuronal computation.

Modern Applications of Photo-Elasticity

1948 ◽  
Vol 158 (1) ◽  
pp. 235-250 ◽  
Author(s):  
R. B. Heywood
Keyword(s):  
Stress Analysis ◽  
Three Dimensional ◽  
Polarized Light ◽  
Gear Wheel ◽  
Connecting Rod ◽  
Complicated Shape ◽  
Poppet Valve ◽  
Aero Engine

It has long been known that polarized light may be employed to analyse the stresses occurring in engineering parts. Recent modifications have simplified the apparatus required, so giving a wider scope to the application of photo-elasticity to engineering. The method of preparing transparent models for stress analysis is discussed, and the significance of the photo-elastic fringes is explained. Only the boundary stresses in the model are considered, and their importance is demonstrated by means of examples, such as the modification of the design of aero-engine parts so that a substantial increase in strength is attained. The procedure for evolving the best shape of fillet for a particular set of conditions is given. The three-dimensional “freezing” technique is described, a technique which enables the boundary stresses in parts of complicated shape to be determined, and has the further advantage that an assessment of the elastic distortions may be made. Examples of the application of photo-elasticity include a connecting rod, crankshaft, poppet valve, and gear wheel.

ANALYSIS ON ATTITUDE POSITION OF EARTH CENTERED INERTIAL (ECI) BASED ON RAZAKSAT DATA

2015 ◽  
Vol 76 (12) ◽  
Author(s):  
Mohd Zamri Hasan ◽  
Sazali Yaacob ◽  
Amran Ahmed ◽  
Nor Hazadura Hamzah ◽  
Shamshul Bahar Yaakob ◽  
...  
Keyword(s):  
Coordinate System ◽  
Reference Frame ◽  
Earth Rotation ◽  
Attitude Determination ◽  
Three Dimensional ◽  
Measurement Data ◽  
Inertial Reference Frame ◽  
Determination System ◽  
Line Elements

Attitude determination system (ADS) is a process to control the orientation of satellite to make sure that the orientation of satellite is relative to inertial reference frame such as Earth. Earth Centered Inertial (ECI) is one of reference frame for satellite that determines the attitude in three dimensional spacecraft. Since RazakSAT orbits on earth, ECI coordinate system will be used for satellite relative to earth rotation. This paper is about the analysis on attitude position of ECI and velocity at X, Y and Z axis based on RazakSAT data. Satellite Tools Kit (STK) is used to estimate the attitude and velocity based on Two Line Elements (TLE) of RazakSAT. The result is compared with RazakSAT measurement data to observe the accuracy of estimation by using STK.

scholarly journals Three-dimensional polarization ray tracing calculus for partially polarized light

2017 ◽  
Vol 25 (22) ◽  
pp. 26973 ◽  
Author(s):  
Haiyang Zhang ◽  
Yi Li ◽  
Changxiang Yan ◽  
Junqiang Zhang
Keyword(s):  
Ray Tracing ◽  
Three Dimensional ◽  
Polarized Light ◽  
Polarization Ray Tracing
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