Influence of errors in assignment of the optical atmospheric parameters on results of reconstruction of the Earth’s surface reflection coefficients from satellite measurements in the visible and near-IR ranges

2016 ◽  
Author(s):  
M. V. Tarasenkov ◽  
V. V. Belov
Keyword(s):  
Reflection Coefficients ◽  
Atmospheric Parameters ◽  
Satellite Measurements ◽  
Surface Reflection ◽  
Near Ir

An exact anelastic model for the free-surface relfection of P and S-I waves

1989 ◽  
Vol 79 (3) ◽  
pp. 842-859
Author(s):  
R. D. Borcherdt ◽  
G. Glassmoyer
Keyword(s):  
Free Surface ◽  
Volumetric Strain ◽  
Major Axis ◽  
P Wave ◽  
Reflection Coefficients ◽  
S Wave ◽  
Low Loss ◽  
Surface Reflection ◽  
Pierre Shale ◽  
Homogeneous Wave

Abstract Exact anelastic solutions incorporating inhomogeneous waves are used to model numerically S-I and P waves incident on the free surface of a low-loss anelastic half-space. Anelastic free-surface reflection coefficients are computed for the volumetric strain and displacement components of inhomogeneous wave fields. For the problem of an incident homogeneous S-I wave in Pierre shale, the largest strain and displacement amplitudes for the reflected P wave occur at angles of incidence for which the particle motion for the reflected inhomogeneous P wave is elliptical (minor/major axis = 0.6), the specific absorption (QP−1) is greater (300 per cent) and the velocity is less (25 per cent) than those for a corresponding homogeneous P wave, the direction of phase propagation is not parallel to the free surface, and the amplitude of the wave shows a significant increase with depth (6 per cent in one wavelength). Energy reflection coefficients computed for this low-loss anelastic model show that energy flow due to interaction of the incident and reflected waves reach maxima (30 per cent of the incident energy) near large but nongrazing angles of incidence. For the problem of an incident homogeneous P wave in Pierre shale, the inhomogeneity of the reflected S wave is shown not to contribute to significant variations in wave field characteristics over those that would be expected for a homogeneous wave.

Retrieval of Reflection Coefficients of the Earth’s Surface from MODIS Satellite Measurements Considering Radiation Polarization

2020 ◽  
Vol 33 (2) ◽  
pp. 179-187
Author(s):  
M. V. Tarasenkov ◽  
A. V. Zimovaya ◽  
V. V. Belov ◽  
M. V. Engel
Keyword(s):  
Reflection Coefficients ◽  
Radiation Polarization ◽  
Satellite Measurements

scholarly journals Surface and optical properties of calcium carbonate paper

2021 ◽  
Vol 57 (4) ◽  
pp. 472-479
Author(s):  
I. I. Ismailov ◽  
Kh. A. Babakhanova ◽  
A. A. Sadriddinov ◽  
M. A. Babahanova ◽  
D. Sh. Saidova
Keyword(s):  
Optical Properties ◽  
Calcium Carbonate ◽  
Quantitative Assessment ◽  
Incident Light ◽  
Reflection Coefficients ◽  
Paper Sample ◽  
Surface Reflection ◽  
Coated Papers ◽  
Paper Company ◽  
The Difference

The article investigates the surface and optical properties of calcium carbonate paper obtained at the UzbekChinese enterprise Fergana stone paper company (Uzbekistan), in order to identify the possibility of their use at printing enterprises for printing multicolor products using traditional printing methods. According to the results of a quantitative assessment of the surface quality by the indirect Beck method, we can say that paper sample 1 has a smoothness like coated paper (750–1500 s), paper samples 2 and 3 – like calendered paper, so that these paper samples can be recommended for prints with increased quality requirements. Smaller values of roughness Ra and small depressions, expressed by darkening in the topographic AFM images, characterized sufficient homogeneity and density of the structure. It was also revealed that the surface of the paper samples has a high ability to specularly reflect the incident light, since the percentage of surface reflection is similar to that of coated papers. Samples of paper have a whiteness of about 90 % and do not have a tint, since the difference between the maximum and minimum values of the reflection coefficients on a white stack is not more than 10 %. The tested paper samples can be recommended without restrictions for double-sided printing, since the opacity index is more than 92 %.

DECOMPOSITION AND SUPPRESSION OF MULTIPLE REFLECTIONS

Geophysics ◽  
1965 ◽  
Vol 30 (1) ◽  
pp. 54-71 ◽  
Author(s):  
R. J. Watson
Keyword(s):  
Reflection Coefficients ◽  
Detailed Knowledge ◽  
Multiple Reflections ◽  
Surface Reflection ◽  
Multiple Function ◽  
First Order ◽  
Positive Feedback Circuit ◽  
Reflectivity Function ◽  
Correlation Search ◽  
Order Surface

Multiple reflections constitute an important source of “noise” on seismograms. Because multiples are related to the primary reflectivity function r(t) in a very complicated way, the suppression of all multiple reflections on a single seismic trace is unlikely without a detailed knowledge of the reflectivity function itself. This paper describes a series of approximations in which multiple reflections are decomposed into component subsets. For certain types of velocity functions, one or two of these subsets form a sufficiently good approximation to the complete multiple process to at least predict the strongest multiples present on a field seismogram. The subset approximations to the complete multiple function include the first‐order surface multiples, i.e., three‐bounce multiples having a second reflection at the surface. The expression for this set of multiples is [Formula: see text], where the * stands for convolution, and [Formula: see text] is the surface reflection coefficient. Computations of this set are compared with the complete multiple function for logs from Alberta, Canada, and southern Mississippi. A further approximation, called the [Formula: see text], is valid in areas where a few reflection coefficients, r⁁(t), are responsible for the bulk of the multiple noise. [Formula: see text] consists of all first‐order surface multiples which have a contribution from the r⁁(t) zone. The above‐mentioned velocity logs are used to illustrate the [Formula: see text] approximation. The [Formula: see text] function is compared with the complete first‐order surface multiple function for the two logs. A method for suppressing the multiples described by the approximations is proposed. The technique is illustrated for the [Formula: see text] approximation but can be extended to higher‐order approximations. It consists of a positive feedback circuit in which a reflectivity function is simulated along with appropriate time‐variant gain adjustments. In order to realize the computation, it is necessary to find the time and amplitude of the reflection coefficients responsible for the large‐amplitude multiple reflections. Several methods for providing this information are discussed and a correlation search technique is illustrated with examples. Finally, the suppression technique is illustrated with live seismic data on two record sections from two different areas showing data before and after multiple suppression. In both cases the [Formula: see text] approximation was adequate.

scholarly journals Balloon-borne Limb profiling of UV/vis skylight radiances, O<sub>3</sub>, NO<sub>2</sub> and BrO: technical set-up and validation of the method

2004 ◽  
Vol 4 (6) ◽  
pp. 7631-7665 ◽  
Author(s):  
F. Weidner ◽  
H. Bösch ◽  
H. Bovensmann ◽  
J. P. Burrows ◽  
A. Butz ◽  
...  
Keyword(s):  
Electrochemical Cell ◽  
Trace Gas ◽  
The Novel ◽  
Atmospheric Parameters ◽  
Near Ir ◽  
Solar Occultation ◽  
Novel Method ◽  
Gas Measurements ◽  
Set Up

Abstract. A novel light-weight, elevation scanning and absolutely calibrated UV/vis spectrometer and its application to balloon-borne Limb radiance and trace gas measurements is described. Its performance and the novel method of balloon-borne UV/vis Limb trace gas measurements has been tested against simultaneous observations of the same atmospheric parameters available from either (a) in-situ instrumentation (cf., by an electrochemical cell (ECC) ozone sonde also deployed aboard the gondola) or (b) trace gas profiles from inferred UV/vis/near IR solar occultation measurements performed on the same payload. The novel technique is also cross validated with radiative transfer modelling. Reasonable agreement is found (a) between measured and simulated Limb radiances and (b) inferred Limb O3, NO2 and BrO and otherwise measured profiles when properly accounting for all relevant atmospheric parameters (temperature T, pressure P, aerosol extinction, and major absorbers).

scholarly journals THE PROGRAM FOR CALCULATING THE ASYMMETRY COEFFICIENTS OF AEROSOL SCATTERING IN THE RED AND NEAR IR REGIONS OF THE SPECTRUM

2021 ◽  
pp. 163-167
Author(s):  
В.В. Пашнев ◽  
Ю.Я. Матющенко ◽  
В.В. Белозерских ◽  
А.В. Калачев
Keyword(s):  
Block Diagram ◽  
Scattered Light ◽  
Atmospheric Parameters ◽  
Asymmetry Coefficient ◽  
Angular Variation ◽  
Acceptable Error ◽  
Near Ir ◽  
Aerosol Scattering ◽  
Calculation Results ◽  
The Asymmetry

В настоящей работе представлено программное обеспечение, реализующее методику определения аэрозольного коэффициента асимметрии из результатов наблюдений интегрального коэффициента рассеянных световых потоков, оптической толщи и альбедо местности интерполяционным путем без применения аппарата решения обратных задач. В качестве исходных используются данные измерений углового хода яркости дневного безоблачного неба в солнечном альмукантарате при разной спектральной прозрачности атмосферы и альбедо подстилающей поверхности. Наблюдения выполняются в длинах волн 675, 870 и 1020 нм при зенитных углах Солнца 65÷750, при этом яркость может измеряться в любых единицах, включая непосредственно отсчеты фотометра. При обработке результатов мониторинговых наблюдений даже на одной длине волны требуется производить значительное количество однотипных вычислений, что делает задачу автоматизации расчетов атмосферных параметров, в частности, коэффициентов асимметрии, безусловно актуальной. Изложены требования к входным данным, представлена блок-схема алгоритма и описание интерфейса пользователя программы. Результаты расчетов выводятся в табличной форме. Программаобеспечивает приемлемую погрешность определения коэффициентов асимметрии и может быть использована в геофизике и климатологии при проведении расчетов поступления рассеянной солнечной радиации на земную поверхность с целью последующей оценки размеров частиц. In this paper, software is presented that implements the method for determining the aerosol asymmetry coefficient from the results of observations of the integral coefficient of scattered light fluxes, optical depth and albedo of the terrain by interpolation without using an apparatus for solving inverse problems. The data of measurements of the angular variation of the brightness of the daytime cloudless sky in the solar almucantar with different spectral transparency of the atmosphere and the albedo of the underlying surface are used as the initial data. Observations are carried out at wavelengths of 675, 870 and 1020 nm at zenith angles of the Sun 65 ÷ 750, while the brightness can be measured in any unit, including directly the readings of the photometer. When processing the results of monitoring observations, even at one wavelength, it is required to perform a significant number of calculations of the same type, which makes the task of automating the calculations of atmospheric parameters, in particular, the asymmetry coefficients, undoubtedly relevant. Requirements for the input data are stated, a block diagram of the algorithm and a description of the user interface of the program are presented. The calculation results are displayed in tabular form. The program provides an acceptable error in determining the asymmetry coefficients and can be used in geophysics and climatology when calculating the arrival of scattered solar radiation on the earth's surface in order to further estimate the particle size.

Computations of rough surface reflection coefficients in a waveguide

1996 ◽  
Vol 100 (4) ◽  
pp. 2834-2834
Author(s):  
David H. Berman
Keyword(s):  
Rough Surface ◽  
Reflection Coefficients ◽  
Surface Reflection
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