scholarly journals Surface Shape Detection with a Single Far-Field Intensity by Combined Amplitude and Phase Retrieval

2019 ◽  
Vol 2019 ◽  
pp. 1-10
Author(s):  
Huiliang Jin ◽  
Jianhui Huang ◽  
Qian Ye ◽  
Guoxiang Meng ◽  
Binbin Xiang ◽  
...  
Keyword(s):  
Field Intensity ◽  
Phase Retrieval ◽  
Decomposition Analysis ◽  
Surface Shape ◽  
Detection Methods ◽  
Far Field ◽  
Shape Detection ◽  
Good Convergence ◽  
Antenna Surface ◽  
First Time

The efficiency of a reflector antenna highly depends on its surface shape. In order to ensure a good convergence, the conventional phase retrieval based shape detection schemes require that several far-field intensities be scanned, focused, or defocused. For large reflector antennas, the scanning process is time consuming. This paper proposes a new shape detection method that requires only single far-field intensity. Unlike existing shape detection methods, it retrieves both the amplitude and the phase, based on the fact that a deformed shape causes change not only in the aperture phase but also in the aperture amplitude. Through even-odd decomposition analysis, it is found that in the case of small and smooth deformation, “odd-phase” and “even-amplitude” can be directly recovered from one focused far-field intensity. This leads to the recovery of both the odd and the even parts of the antenna surface shape simultaneously. By combining amplitude retrieval and phase retrieval, this work achieves for the first time the shape detection with only one scan.

Small-phase retrieval using single focused far-field intensity

Optik ◽  
2020 ◽  
Vol 218 ◽  
pp. 164904
Author(s):  
Qian Ye ◽  
Dafei Xiao
Keyword(s):  
Field Intensity ◽  
Phase Retrieval ◽  
Far Field ◽  
Small Phase

scholarly journals Phase retrieval from experimental far-field intensity data

1990 ◽  
Vol 7 (3) ◽  
pp. 434 ◽  
Author(s):  
M. J. Pérez-Ilzarbe ◽  
M. Nieto-Vesperinas ◽  
R. Navarro
Keyword(s):  
Field Intensity ◽  
Phase Retrieval ◽  
Far Field ◽  
Intensity Data

ANALYSIS OF THE FUNCTIONING OF MARINE ECOSYSTEMS ON CHANGING THE PARAMETERS OF THE BIOLUMINESCENCE FIELD ON THE CRIMEAN BLACK SEA SHELF

2017 ◽  
Author(s):  
Svetlana Rubtsova ◽  
Svetlana Rubtsova ◽  
Natalya Lyamina ◽  
Natalya Lyamina ◽  
Aleksey Lyamin ◽  
...  
Keyword(s):  
Black Sea ◽  
Field Intensity ◽  
Deep Water ◽  
Coastal Waters ◽  
Integrated Management ◽  
Abiotic Factors ◽  
Environmental Safety ◽  
The Black Sea ◽  
Intensity Increase ◽  
First Time

The concept of a new approach to environmental assessment is offered in the system of integrated management of the resource and environmental safety of the coastal area of the Black Sea. The studies of the season and daily changeability in the bioluminescence field in the Sevastopol coastal waters has been conducted. For the first time considerable differences in the bioluminescence field seasonal changes in the surface and deep water layers and the reasons conditioning this phenomenon have been shown, using a method of multidimensional statistical analysis. The bioluminescence field vertical profile change in the Black sea coastal waters in the autumn period at night has been studied. It has been shown that according to the character of bioluminescence parameters dynamics a water column can be divided into layers: upper (0 – 35 m) and deep water (36 – 60 m). It has been revealed that life rhythms of the plankton community are the main reason for the bioluminescence field intensity variability. It has been revealed that 14-hour periodicity of the bioluminescence field is related to the changes in light and its variations with 2,5…4,5 hours are conditioned by planktonts endogenous daily rhythms. And here biotic factors effect mostly periodicity of the bioluminescence field intensity increase and fall down at the dark time of the day. Abiotic factors are of less importance in circadian rhythmic of the bioluminescence field in the neritic zone.

Relationship between large-aperture optical components of striated surface shape and focal spot characteristics in the far-field

2015 ◽  
Author(s):  
Zemin Lei ◽  
Xiaoyan Sun ◽  
Xianhua Yin ◽  
Fengnian Lv ◽  
Zhen Zhang ◽  
...  
Keyword(s):  
Focal Spot ◽  
Surface Shape ◽  
Far Field ◽  
Optical Components ◽  
Large Aperture

scholarly journals The use of differential calculation methods for the destruction of copolymers of polyethylene glycol fumarate with the acrylic acid

2020 ◽  
Vol 99 (3) ◽  
pp. 4-10
Author(s):  
M.Zh. Burkeev ◽  
◽  
A.Zh. Sarsenbekova ◽  
A.N. Bolatbay ◽  
E.M. Tazhbaev ◽  
...  
Keyword(s):  
Activation Energy ◽  
Polyethylene Glycol ◽  
Acrylic Acid ◽  
Polyester Resin ◽  
Thermodynamic Characteristics ◽  
Nitrogen Atmosphere ◽  
Inert Medium ◽  
Good Convergence ◽  
Sample Decomposition ◽  
First Time

In this work, the thermal decomposition of copolymers based on polyethylene glycol fumarate with the acrylic acid using various ratios of initial monomers has been studied for the first time. The samples were studied in air and nitrogen. According to the thermograms analysis, it was found that the copolymer sample decomposition begins at higher temperatures for a copolymer with high content of polyester resin. The copolymer is vigorously oxidized by the oxygen when heated in air, and one can observe almost complete sample decomposition, whereas it decomposes with a residue of ~ 15% in an inert medium. The activation energies for copolymers with different compositions were estimated using the differential methods of Freeman-Carroll, Achar and Sharpe-Wentworth. The activation energy values found by the three methods demonstrated a good convergence. It was shown that, the activation energy values are higher (~ 200 kJ/mol in the inert medium, and ~ 95 kJ/mol in the oxygen atmosphere) for a copolymer with a lower composition of polyester resin, and the activation energy is ~180 and ~85 kJ/mol for a copolymer with a greater composition of p-EGF-AA. The copolymer is more thermostable in the nitrogen atmosphere according to the kinetic parameters. Additionally, there were determined the thermodynamic characteristics, such as the Gibbs energy (∆G) and the entropy (∆S). They also confirm the destruction process dependence on the components ratio in the synthesized copolymer.

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