Solar radiation focusing: analysis and determination of reflecting facets point spread functions and alignment errors

<div>This paper deals with microwave subsurface imaging obtained by a migration-like inversion scheme, for a 2D monostatic scalar configuration and a two-layered background medium. The focus is on the determination of a data sampling strategy which allows to reduce the number of required measurements and at the same time keep the same performance in the reconstructions. To this end, the measurement points are determined in order to approximate the point-spread function corresponding to the ideal continuous case (i.e., the case in which the data space is not sampled at all). Basically, thanks to suitable variable transformations the point-spread functions is recast as a Fourier-like operator and this provides insight to devise the sampling scheme. It is shown that resulting measurement spatial positions are non-uniformly arranged across the measurement domain and their number can be much lower than the one provided by some literature standard sampling criteria. The study also contains a comparison with the free space case so as to highlight the role played by the half-space that schematized the subsurface scattering scenario on the number and the locations of the measurement points. Numerical examples are also included to check the theoretical arguments.</div>

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An on Orbit Determination of Point Spread Functions for the Interface Region Imaging Spectrograph

Solar Physics ◽

10.1007/s11207-018-1347-9 ◽

2018 ◽

Vol 293 (9) ◽

Cited By ~ 6

Author(s):

Hans Courrier ◽

Charles Kankelborg ◽

Bart De Pontieu ◽

Jean-Pierre Wülser

Keyword(s):

Orbit Determination ◽

Interface Region ◽

Point Spread Functions ◽

Point Spread ◽

Imaging Spectrograph

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High Precision Crowded Field Photometry

Highlights of Astronomy ◽

10.1017/s1539299600008613 ◽

1989 ◽

Vol 8 ◽

pp. 651-656

Author(s):

Peter Linde

Keyword(s):

High Precision ◽

List Type ◽

Point Spread Functions ◽

Error Sources ◽

Point Spread ◽

Spread Function ◽

Star Group ◽

Local Background ◽

Definition Of

AbstractMethods have been developed for high precision photometry in crowded stellar fields. The procedure includes the following steps:• Determination of a two-dimensional point spread function• Definition of groups of stars with mutually overlapping images• Determination of local background for each star group• Simultaneous fitting of point spread functions, one for each star in the groupThe Lund approach emphasizes interactivity. Many fundamental procedures are facilitated by the use of an optimised image display. Extensive modelling has been done to study the influence of various error sources.

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Spatial Sampling in Monostatic Subsurface Radar Imaging

10.36227/techrxiv.12690155.v1 ◽

2020 ◽

Author(s):

Maria Antonia Maisto ◽

Rocco Pierri ◽

Raffaele Solimene

Keyword(s):

Sampling Strategy ◽

Data Sampling ◽

Subsurface Scattering ◽

Point Spread Functions ◽

Point Spread ◽

Measurement Domain ◽

Standard Sampling ◽

The One ◽

Space Case

<div>This paper deals with microwave subsurface imaging obtained by a migration-like inversion scheme, for a 2D monostatic scalar configuration and a two-layered background medium. The focus is on the determination of a data sampling strategy which allows to reduce the number of required measurements and at the same time keep the same performance in the reconstructions. To this end, the measurement points are determined in order to approximate the point-spread function corresponding to the ideal continuous case (i.e., the case in which the data space is not sampled at all). Basically, thanks to suitable variable transformations the point-spread functions is recast as a Fourier-like operator and this provides insight to devise the sampling scheme. It is shown that resulting measurement spatial positions are non-uniformly arranged across the measurement domain and their number can be much lower than the one provided by some literature standard sampling criteria. The study also contains a comparison with the free space case so as to highlight the role played by the half-space that schematized the subsurface scattering scenario on the number and the locations of the measurement points. Numerical examples are also included to check the theoretical arguments.</div>

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Determination of the ScaRaB FM1 broadband channel point spread functions

IEEE Transactions on Geoscience and Remote Sensing ◽

10.1109/36.774711 ◽

1999 ◽

Vol 37 (4) ◽

pp. 2004-2010 ◽

Cited By ~ 2

Author(s):

S. Dewitte ◽

P. Boekaerts ◽

F. Sirou

Keyword(s):

Point Spread Functions ◽

Point Spread

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Determination of the Point Spread Function of a Computer-Generated Lens Formed by a Phase Light Modulator

Optics and Spectroscopy ◽

10.1134/s0030400x20070231 ◽

2020 ◽

Vol 128 (7) ◽

pp. 1036-1040 ◽

Cited By ~ 1

Author(s):

N. G. Stsepuro ◽

G. K. Krasin ◽

M. S. Kovalev ◽

V. N. Pestereva

Keyword(s):

Point Spread Function ◽

Light Modulator ◽

Point Spread ◽

Spread Function

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Optimal design of the solar tracking system of parabolic trough concentrating collectors

International Journal of Low-Carbon Technologies ◽

10.1093/ijlct/ctaa065 ◽

2020 ◽

Vol 15 (4) ◽

pp. 613-619

Author(s):

Li Kong ◽

Yunpeng Zhang ◽

Zhijian Lin ◽

Zhongzhu Qiu ◽

Chunying Li ◽

...

Keyword(s):

Numerical Simulation ◽

Solar Radiation ◽

Tracking System ◽

Low Cost ◽

Parabolic Trough ◽

The North ◽

Tracking Mode ◽

Solar Tracking ◽

East West

Abstract The present work aimed to select the optimum solar tracking mode for parabolic trough concentrating collectors using numerical simulation. The current work involved: (1) the calculation of daily solar radiation on the Earth’s surface, (2) the comparison of annual direct solar radiation received under different tracking modes and (3) the determination of optimum tilt angle for the north-south tilt tracking mode. It was found that the order of solar radiation received in Shanghai under the available tracking modes was: dual-axis tracking > north-south Earth’s axis tracking > north-south tilt tracking (β = 15°) > north-south tilt tracking (β = 45) > north-south horizontal tracking > east-west horizontal tracking. Single-axis solar tracking modes feature simple structures and low cost. This study also found that the solar radiation received under the north-south tilt tracking mode was higher than that of the north-south Earth’s axis tracking mode in 7 out of 12 months. Therefore, the north-south tilt tracking mode was studied separately to determine the corresponding optimum tilt angles in Haikou, Lhasa, Shanghai, Beijing and Hohhot, respectively, which were shown as follows: 18.81°, 27.29°, 28.67°, 36.21° and 37.97°.

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