DISAMBIGUATION OF INVERSE PROBLEM SOLUTION FOR RETRIEVAL OF RAIN INTENSITY USING DOUBLE FREQUENCY RADAR SENSING

2015 ◽  
Vol 74 (17) ◽  
pp. 1535-1543
Author(s):  
G. I. Khlopov ◽  
G. B. Veselovska ◽  
O. A. Voitovych
Keyword(s):  
Inverse Problem ◽  
Problem Solution ◽  
Rain Intensity ◽  
Double Frequency ◽  
Inverse Problem Solution ◽  
Radar Sensing

scholarly journals The influence of a fallacy in specific effective scattering surface evaluation on the result of double-frequency retrieval of rain intensity

2021 ◽  
Vol 26 (2) ◽  
pp. 16-22
Author(s):  
A. Linkova ◽  
Keyword(s):  
Inverse Problem ◽  
Crop Yields ◽  
Remote Sensing Data ◽  
Problem Solution ◽  
Microwave Range ◽  
Rain Intensity ◽  
Double Frequency ◽  
Received Power ◽  
Regularization Techniques ◽  
Effective Scattering Surface

Subject and Purpose. The amount of precipitation is important information for the agro-climatic justification of agro-technical and reclamation actions directly controlling crop yields. The inverse problem of rain intensity retrieval from the remote sensing data is an incorrect mathematical physical problem described by a nonlinear integral equation. The purpose of this work is to analyze how errors in the specific effective scattering surface evaluation affect the results of double-frequency retrieval of the rain intensity obtained through the inverse problem solution by the previously proposed method. Methods and Methodology. Numerical simulation by using an approach based on regularization techniques and intended for the integral scattering equation solution is carried out for double-frequency sensing in the microwave range Results. Numerical simulations of the rain intensity retrieval have been performed at the operating wavelengths 0.82 and 3.2 cm in the range 1…30 mm/h and for different values of received power errors. It has been shown that an error in the specific effective scattering surface evaluation has a greater effect on the reliability of the intensity retrieval in the shorter wavelength case. And it exerts practically no effect (not exceeding 5 %) at the longer wavelength and at the rain intensity below 15 mm/h, which, however, is true for heavier rains, too. Conclusion. The analysis of the results has shown that the error of the rain intensity retrieval remains within acceptable limits (below 20 %) provided that the error in the specific effective scattering surface evaluation does not exceed 15 % at the shorter wavelength. At the longer wavelength, it can reach 30 %.

Inverse problem solution for a laser flash studies of a thin layer coatings

2017 ◽  
Vol 27 (3) ◽  
pp. 698-710 ◽  
Author(s):  
Wit Stryczniewicz ◽  
Janusz Zmywaczyk ◽  
Andrzej Jaroslaw Panas
Keyword(s):  
Inverse Problem ◽  
Heat Conduction ◽  
Thin Layer ◽  
Laser Flash ◽  
Problem Solution ◽  
Flake Graphite ◽  
Estimation Technique ◽  
Content Type ◽  
Inverse Problem Solution ◽  
Layer Sample

Purpose The paper aims to discuss the inverse heat conduction methodology in solution of a certain parameter identification problem. The problem itself concerns determination of the thermophysical properties of a thin layer coating by applying the laser flash apparatus. Design/methodology/approach The modelled laser flash diffusivity data from the three-layer sample investigation are used as input for the following parameter estimation procedure. Assuming known middle layer, i.e. substrate properties, the thermal diffusivity (TD) of the side layers’ material is determined. The estimation technique utilises the finite element method for numerical solution of the direct, 2D axisymmetric heat conduction problem. Findings The paper presents methodology developed for a three-layer sample studies and results of the estimation technique testing and evaluation based on simulated data. The multi-parametrical identification procedure results in identification of the out of plane thin layer material diffusivity from the inverse problem solution. Research limitations/implications The presentation itself is limited to numerical simulation data, but it should be underlined that the flake graphite thermophysical parameters have been utilised in numerical tests. Practical implications The developed methodology is planned to be applied in detailed experimental studies of flake graphite. Originality/value In the course of a present study, a methodology of the thin-coating layer TD determination was developed. In spite of the fact that it has been developed for the graphite coating investigation, it was planned to be universal in application to any thin–thick composite structure study.

scholarly journals The Art of Surface Imaging

1991 ◽  
Vol 130 ◽  
pp. 309-320 ◽  
Author(s):  
N.E. Piskunov
Keyword(s):  
Inverse Problem ◽  
High Resolution ◽  
Stellar Atmosphere ◽  
High Resolution Spectroscopy ◽  
Regularization Methods ◽  
Problem Solution ◽  
Surface Imaging ◽  
Late Type ◽  
Inverse Problem Solution ◽  
Additional Constraints

AbstractWe intend to analyze the reliability of surface imaging of stars based on high resolution spectroscopy and the technique of inverse problem solution. Both astrophysical and mathematical aspects including different regularization methods are reviewed. The influence of the different factors on the resulting map is discussed and it is shown that the simultaneous use of different kinds of observational data (spectroscopy, photometry, polarimetry etc.) is very useful in providing additional constraints for the solution. The recent results in the surface imaging of Cp- and late-type stars show the way for further progress: the use of more adequate mathematical description of the stellar atmosphere and the simultaneous consideration of various surface inhomogeneities.

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