Application of Single and Multiple-Scattering Theories to Analyses of Space-Borne Cloud Radar and Lidar Data

2020 ◽  
pp. 1-37
Author(s):  
Kaori Sato ◽  
Hajime Okamoto
Keyword(s):  
Multiple Scattering ◽  
Lidar Data ◽  
Cloud Radar

scholarly journals Development of a multiple-field-of-view multiple-scattering polarization lidar: comparison with cloud radar

2016 ◽  
Vol 24 (26) ◽  
pp. 30053 ◽  
Author(s):  
Hajime Okamoto ◽  
Kaori Sato ◽  
Tomoaki Nishizawa ◽  
Nobuo Sugimoto ◽  
Toshiyuki Makino ◽  
...  
Keyword(s):  
Multiple Scattering ◽  
Field Of View ◽  
Cloud Radar ◽  
Multiple Field

scholarly journals Application of multiple-scattering polarization lidar for the evaluation of space-borne lidar algorithms

2018 ◽  
Vol 176 ◽  
pp. 02014
Author(s):  
Hajime Okamoto ◽  
Kaori Sato ◽  
Shuichiro Katagiri ◽  
Masahiro Fujikawa ◽  
Tomoaki Nishizawa ◽  
...  
Keyword(s):  
Monte Carlo ◽  
Monte Carlo Simulations ◽  
Multiple Scattering ◽  
System Performance ◽  
Field Of View ◽  
Depolarization Ratio ◽  
Radar Observations ◽  
Cloud Radar ◽  
Enhanced Backscattering

Multi-field of view multiple-scattering polarization lidar (MFMSPL) has been developed to measure enhanced backscattering and depolarization ratio from optically thick clouds. Collocated cloud radar observations and Monte Carlo simulations supported the system performance such as cloud detectability and values of depolarization ratio. The system is used to evaluate/improve algorithms for space-borne lidar such as CALIOP on CALIPSO and ATLID on EarthCARE.

scholarly journals Assessment of Cloudsat Reflectivity Measurements and Ice Cloud Properties Using Ground-Based and Airborne Cloud Radar Observations

2009 ◽  
Vol 26 (9) ◽  
pp. 1717-1741 ◽  
Author(s):  
A. Protat ◽  
D. Bouniol ◽  
J. Delanoë ◽  
E. O’Connor ◽  
P. T. May ◽  
...  
Keyword(s):  
Multiple Scattering ◽  
Field Experiments ◽  
Weighted Mean Difference ◽  
Time Lag ◽  
Supercooled Liquid ◽  
Cloud Base ◽  
Ice Cloud ◽  
Cloud Radar ◽  
Cloud Properties ◽  
Radar Calibration

Abstract A quantitative assessment of Cloudsat reflectivities and basic ice cloud properties (cloud base, top, and thickness) is conducted in the present study from both airborne and ground-based observations. Airborne observations allow direct comparisons on a limited number of ocean backscatter and cloud samples, whereas the ground-based observations allow statistical comparisons on much longer time series but with some additional assumptions. Direct comparisons of the ocean backscatter and ice cloud reflectivities measured by an airborne cloud radar and Cloudsat during two field experiments indicate that, on average, Cloudsat measures ocean backscatter 0.4 dB higher and ice cloud reflectivities 1 dB higher than the airborne cloud radar. Five ground-based sites have also been used for a statistical evaluation of the Cloudsat reflectivities and basic cloud properties. From these comparisons, it is found that the weighted-mean difference ZCloudsat − ZGround ranges from −0.4 to +0.3 dB when a ±1-h time lag around the Cloudsat overpass is considered. Given the fact that the airborne and ground-based radar calibration accuracy is about 1 dB, it is concluded that the reflectivities of the spaceborne, airborne, and ground-based radars agree within the expected calibration uncertainties of the airborne and ground-based radars. This result shows that the Cloudsat radar does achieve the claimed sensitivity of around −29 dBZ. Finally, an evaluation of the tropical “convective ice” profiles measured by Cloudsat has been carried out over the tropical site in Darwin, Australia. It is shown that these profiles can be used statistically down to approximately 9-km height (or 4 km above the melting layer) without attenuation and multiple scattering corrections over Darwin. It is difficult to estimate if this result is applicable to all types of deep convective storms in the tropics. However, this first study suggests that the Cloudsat profiles in convective ice need to be corrected for attenuation by supercooled liquid water and ice aggregates/graupel particles and multiple scattering prior to their quantitative use.

Analysis of STEM micrographs of thick objects

1978 ◽  
Vol 36 (2) ◽  
pp. 106-107
Author(s):  
S. Golladay
Keyword(s):  
Inelastic Scattering ◽  
Multiple Scattering ◽  
Mass Distribution ◽  
Cross Sections ◽  
Phase Contrast ◽  
Image Point ◽  
Contrast Effects ◽  
Total Cross Sections ◽  
Elastic And Inelastic Scattering

The theory of multiple scattering has been worked out by Groves and comparisons have been made between predicted and observed signals for thick specimens observed in a STEM under conditions where phase contrast effects are unimportant. Independent measurements of the collection efficiencies of the two STEM detectors, calculations of the ratio σe/σi = R, where σe, σi are the total cross sections for elastic and inelastic scattering respectively, and a model of the unknown mass distribution are needed for these comparisons. In this paper an extension of this work will be described which allows the determination of the required efficiencies, R, and the unknown mass distribution from the data without additional measurements or models. Essential to the analysis is the fact that in a STEM two or more signal measurements can be made simultaneously at each image point.

Background Fitting in the Low-Loss Region of Electron Energy Loss Spectra

1990 ◽  
Vol 48 (2) ◽  
pp. 56-57
Author(s):  
C P Scott ◽  
A J Craven ◽  
C J Gilmore ◽  
A W Bowen
Keyword(s):  
Energy Loss ◽  
Multiple Scattering ◽  
Simple Form ◽  
Single Scattering ◽  
Low Loss ◽  
Characteristic Energy ◽  
Normal Method ◽  
Fitting In ◽  
Electron Energy Loss ◽  
Electron Energy Loss Spectra

The normal method of background subtraction in quantitative EELS analysis involves fitting an expression of the form I=AE-r to an energy window preceding the edge of interest; E is energy loss, A and r are fitting parameters. The calculated fit is then extrapolated under the edge, allowing the required signal to be extracted. In the case where the characteristic energy loss is small (E < 100eV), the background does not approximate to this simple form. One cause of this is multiple scattering. Even if the effects of multiple scattering are removed by deconvolution, it is not clear that the background from the recovered single scattering distribution follows this simple form, and, in any case, deconvolution can introduce artefacts.The above difficulties are particularly severe in the case of Al-Li alloys, where the Li K edge at ~52eV overlaps the Al L2,3 edge at ~72eV, and sharp plasmon peaks occur at intervals of ~15eV in the low loss region. An alternative background fitting technique, based on the work of Zanchi et al, has been tested on spectra taken from pure Al films, with a view to extending the analysis to Al-Li alloys.

MULTIPLE SCATTERING EFFECTS IN THE COBALT K-EDGE EXAFS OF METAL CARBONYL COMPLEXES

1986 ◽  
Vol 47 (C8) ◽  
pp. C8-589-C8-592
Author(s):  
N. BINSTED ◽  
S. L. COOK ◽  
J. EVANS ◽  
R. J. PRICE ◽  
G. N. GREAVES
Keyword(s):  
Multiple Scattering ◽  
Metal Carbonyl ◽  
Carbonyl Complexes ◽  
Metal Carbonyl Complexes ◽  
Scattering Effects ◽  
Multiple Scattering Effects

Multiparametric crystallography using the diversity of multiple scattering patterns for Bragg and diffuse waves. Method of standing diffuse waves

2011 ◽  
Vol 181 (7) ◽  
pp. 681 ◽  
Author(s):  
V.B. Molodkin ◽  
A.P. Shpak ◽  
M.V. Kovalchuk ◽  
V.F. Machulin ◽  
V.L. Nosik
Keyword(s):  
Multiple Scattering
Sign in / Sign up

Export Citation Format

Share Document