Solar instruments on the P78-1 spacecraft

Solar Physics ◽  
1983 ◽  
Vol 86 (1-2) ◽  
pp. 9-17 ◽  
Author(s):  
G. A. Doschek
Keyword(s):  
Solar Instruments

Obtainable Method of Measuring the Solar Radiant Flux Based on Silicone Photodiode Element

2016 ◽  
Vol 824 ◽  
pp. 477-484 ◽  
Author(s):  
Miroslav Čekon ◽  
Richard Slávik ◽  
Peter Juras
Keyword(s):  
Solar Radiation ◽  
Solar Irradiance ◽  
Climate Science ◽  
Radiant Flux ◽  
Silicon Photodiode ◽  
Building Science ◽  
Solar Instruments ◽  
Solar Radiation Exposure ◽  
Building Physics

Solar radiation exposure and its monitoring does have not only the importance for climate science and meteorology however is equally of highly relevant use for the field of Building Science as primarily those of analyzing thermal aspects in building physics. Here the measuring of solar irradiance by means of well-established solar instruments can be applied whose advances have been undergoing steep progress. Currently, a silicon photodiode element, as a truly obtainable form, may have a feasible exploitation in the field of building applications concerning the solar radiant flux quantifying. It represents a small optoelectronic element and has a several exploitable advantages. The paper presents a perspective alternative to monitor solar irradiance. Own measurement assembly is proposed and introduced. Initial in-situ measurements are performed and final comparability with existing commercial solar instruments is presented. An obtained correlation with existing types demonstrates its applicability to the field of building science and solar energy.

On-orbit degradation of recent space-based solar instruments and understanding of the degradation processes

2017 ◽  
Author(s):  
M. Meftah ◽  
M. Dominique ◽  
A. BenMoussa ◽  
I. E. Dammasch ◽  
D. Bolsée ◽  
...  
Keyword(s):  
Degradation Processes ◽  
Solar Instruments

scholarly journals On-Orbit Degradation of Solar Instruments

Solar Physics ◽  
2013 ◽  
Vol 288 (1) ◽  
pp. 389-434 ◽  
Author(s):  
A. BenMoussa ◽  
S. Gissot ◽  
U. Schühle ◽  
G. Del Zanna ◽  
F. Auchère ◽  
...  
Keyword(s):  
Solar Instruments

Inter-Calibrating Satellite Remote Sensors Using High Accuracy NASA CLARREO Pathfinder Instrument

2020 ◽  
Author(s):  
Xu Liu ◽  
Wan Wu ◽  
Qiguang Yang ◽  
Yolanda Shea ◽  
Costy Lukashin ◽  
...  
Keyword(s):  
Infrared Imaging ◽  
Space Station ◽  
Radiant Energy ◽  
Principal Component ◽  
Energy System ◽  
Radiative Transfer Model ◽  
Absolute Calibration ◽  
Transfer Model ◽  
Calibration Uncertainty ◽  
Solar Instruments

<p>NASA is planning to launch a highly accurate hyperspectral sensor to measure Earth-reflected solar radiances from the International Space Station in 2023.  The Climate Absolute Radiance and Refractivity Observatory (CLARREO) Pathfinder (CPF) instrument will have an absolute calibration accuracy of 0.3% (1-sigma), which is about a factor of 5 to 10 more accurate than current satellite reflected solar instruments.  We will describe the CPF approach developed to inter-calibrate the Clouds and Earth’s Radiant Energy System (CERES) and Visible Infrared Imaging Radiometer Suite (VIIRS) instruments.  A Principal Component-based Radiative Transfer Model (PCRTM) is used to perform high fidelity CPF radiance spectra simulation and to extend the spectral range of the CPF to match that of the shortwave CERES reflected solar radiation.  The PCRTM model can also be used to correct small errors due to imperfect angular matching between the CPF/CERES and CPF/VIIRS observation angles.  Examples of inter-calibration uncertainty that is anticipated will be demonstrated using simulated CPF data.</p>

Measuring the Internal ‘Seeing’ of Solar Instruments

1967 ◽  
Vol 1 (2) ◽  
pp. 67-68 ◽  
Author(s):  
C. E. Coulman
Keyword(s):  
Refractive Index ◽  
Wave Propagation ◽  
Plane Wave ◽  
Optical System ◽  
Amplitude Distribution ◽  
Nonuniform Temperature ◽  
Optical Components ◽  
Entrance Aperture ◽  
Infinite Extent ◽  
Solar Instruments

The wavefront from a celestial source is believed to arrive at the outer fringe of the Earth’s atmosphere as a truly plane wave of effectively infinite extent. After propagating through our refractively non-uniform atmosphere this wavefront becomes distorted in shape and exhibits a nonuniform amplitude distribution. At present there is little that can be done to remedy the effects of the atmosphere on wave propagation. However when the wave has been received by the entrance aperture of the observing telescope we should try to design this optical system, including its air-path sections, so as to minimize further distortion of the wavefront. ‘Seeing’ effects within an instrument which concern us in this paper are attributable to air of nonuniform temperature (and hence refractive index) in the sections between the optical components.

A high-speed and high-efficiency imaging polarimeter based on ferroelectric liquid crystal retarders: Design and test

2021 ◽  
Author(s):  
Jing Guo ◽  
Deqing Ren ◽  
Yongtian Zhu ◽  
Xi Zhang
Keyword(s):  
Liquid Crystal ◽  
Magnetic Fields ◽  
High Speed ◽  
High Efficiency ◽  
Modulation Frequency ◽  
Total Efficiency ◽  
Wide Field ◽  
Ferroelectric Liquid Crystal ◽  
Nonlinear Minimization ◽  
Solar Instruments

Abstract Polarimeters play a key role in investigating solar magnetic fields. In this paper, a High speed and high efficiency Imaging POlarimeter (HIPO) is proposed based on a pair of ferroelectric liquid crystal retarders (FLCs), with the ultimate goal of measuring magnetic fields of prominences and filaments from the ground. A unique feature of the HIPO is that it enables high cadence polarization measurements covering a wide field of view (FOV); the modulation frequency of the HIPO is able to achieve ∼100 Hz, which greatly suppresses the seeing-induced crosstalk, and the maximum FOV can reach 62″ × 525″. Additionally, FLC retardances under low and high states were calibrated individually and found to have a slight discrepancy, which is neglected in most works. Based on FLC calibration results, an optimization was performed using a constrained nonlinear minimization approach to obtain the maximum polarimetric efficiency. Specifically, optimized efficiencies of the Stokes Q, U, and V are well balanced and determined as (ξQ, ξU, ξV) = (0.5957, 0.5534, 0.5777), yielding a total efficiency of 0.9974. Their practical efficiencies are measured as (ξQ′, ξU′, ξV′) = (0.5934, 0.5385, 0.5747), slightly below the optimized values but still resulting in a high total efficiency of 0.9861. The HIPO shows advantages in terms of modulation frequency and polarimetric efficiency compared with most other representative ground-based solar polarimeters. In the observations, measurement accuracy is found to be better than 2.7 × 10−3 by evaluating full Stokes Hα polarimetry results of the chromosphere. This work lays a foundation for the development of high-speed and high-accuracy polarimeters for our next-generation solar instruments.

scholarly journals Coronal heating and flaring in QSLs

2010 ◽  
Vol 6 (S273) ◽  
pp. 233-241 ◽  
Author(s):  
Guillaume Aulanier
Keyword(s):  
Magnetic Field ◽  
Magnetic Energy ◽  
Free Field ◽  
Active Regions ◽  
Coronal Heating ◽  
Small Scale ◽  
Flux Tubes ◽  
Solar Instruments ◽  
Field Lines ◽  
New Generation

AbstractQuasi-Separatrix Layers (QSLs) are 3D geometrical objects that define narrow volumes across which magnetic field lines have strong, but finite, gradients of connectivity from one footpoint to another. QSLs extend the concept of separatrices, that are topological objects across which the connectivity is discontinuous. Based on analytical arguments, and on magnetic field extrapolations of the Sun's coronal force-free field above observed active regions, it has long since been conjectured that QSLs are favorable locations for current sheet (CS) formation, as well as for magnetic reconnection, and therefore are good predictors for the locations of magnetic energy release in flares and coronal heating. It is only up to recently that numerical MHD simulations and solar observations, as well as a laboratory experiment, have started to address the validity of these conjectures. When put all together, they suggest that QSL reconnection is involved in the displacement of EUV and SXR brightenings along chromospheric flare ribbons, that it is related with the heating of EUV coronal loops, and that the dissipation of QSL related CS may be the cause of coronal heating in initially homogeneous, braided and turbulent flux tubes, as well as in coronal arcades rooted in the slowly moving and numerous small-scale photospheric flux concentrations, both in active region faculae and in the quiet Sun. The apparent ubiquity of QSL-related CS in the Sun's corona, which will need to be quantified with new generation solar instruments, also suggests that QSLs play an important role in stellar's atmospheres, when their surface radial magnetic fields display complex patterns.

scholarly journals Non-linear equation for estimation of the global solar radiation for any latitude in Egypt

MAUSAM ◽  
2021 ◽  
Vol 51 (1) ◽  
pp. 75-80
Author(s):  
M. T. Y. TADROS
Keyword(s):  
Solar Radiation ◽  
Nonlinear Equation ◽  
Linear Equation ◽  
Global Solar Radiation ◽  
Published Data ◽  
Non Linear Equation ◽  
The World ◽  
Non Linear ◽  
Solar Instruments

The aim of this study is to obtain a nonlinear equation for computation of the monthly solar radiation for any latitude of any place in Egypt, when the recording solar instruments are not available. This equation allows to estimate the monthly values of the Global Solar Radiation for any latitude in Egypt with deviation from the published data (in the world net work), for any month, of about 17%.

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