The impact of assimilating radiance data from the advanced satellite sensor GMI(GPM microwave imager)for typhoon analyses and forecasts was investigated using both a three-dimensional variational(3DVAR)and a hybrid en...The impact of assimilating radiance data from the advanced satellite sensor GMI(GPM microwave imager)for typhoon analyses and forecasts was investigated using both a three-dimensional variational(3DVAR)and a hybrid ensemble-3DVAR method.The interface of assimilating the radiance for the sensor GMI was established in the Weather Research and Forecasting(WRF)model.The GMI radiance data are assimilated for Typhoon Matmo(2014),Typhoon Chan-hom(2015),Typhoon Meranti(2016),and Typhoon Mangkhut(2018)in the Pacific before their landing.The results show that after assimilating the GMI radiance data under clear sky condition with the 3DVAR method,the wind,temperature,and humidity fields are effectively adjusted,leading to improved forecast skills of the typhoon track with GMI radiance assimilation.The hybrid DA method is able to further adjust the location of the typhoon systematically.The improvement of the track forecast is even more obvious for later forecast periods.In addition,water vapor and hydrometeors are enhanced to some extent,especially with the hybrid method.展开更多
Interpreting experimental diagnostics data in tokamaks,while considering non-ideal effects,is challenging due to the complexity of plasmas.To address this challenge,a general synthetic diagnostics(GSD)platform has bee...Interpreting experimental diagnostics data in tokamaks,while considering non-ideal effects,is challenging due to the complexity of plasmas.To address this challenge,a general synthetic diagnostics(GSD)platform has been established that facilitates microwave imaging reflectometry and electron cyclotron emission imaging.This platform utilizes plasma profiles as input and incorporates the finite-difference time domain,ray tracing and the radiative transfer equation to calculate the propagation of plasma spontaneous radiation and the external electromagnetic field in plasmas.Benchmark tests for classical cases have been conducted to verify the accuracy of every core module in the GSD platform.Finally,2D imaging of a typical electron temperature distribution is reproduced by this platform and the results are consistent with the given real experimental data.This platform also has the potential to be extended to 3D electromagnetic field simulations and other microwave diagnostics such as cross-polarization scattering.展开更多
The ability of the Tropical Rainfall Measuring Mission Microwave Imager(TRMM/TMI)for cloud liquid water(CLW)retrieval has been demonstrated in this study.Due to the great sensitivity of the TMI 85.5 GHz channels to CL...The ability of the Tropical Rainfall Measuring Mission Microwave Imager(TRMM/TMI)for cloud liquid water(CLW)retrieval has been demonstrated in this study.Due to the great sensitivity of the TMI 85.5 GHz channels to CLW,the liquid water path(LWP)of nonprecipitating clouds over land can be successfully estimated using the VDISORT model based on the iteration steps.Both the vertical-polarized 85. 5 GHz single-channel method and the polarization-difference of 85.5 GHz method were applied to the LWP estimates over land regions during the Huaihe River Basin Energy and Water Cycle Experiment(HUBEX)in China.The retrieval results show reasonable agreement with the ground-based microwave radiometer measurements.When the surface emissivity or skin temperature is difficult to be made sure,the polarization-difference method shows advantages of providing estimates of LWP especially for low clouds because of its extremely insensitiveness to the surface skin temperature.展开更多
Metamaterials(MTM)can enhance the properties of microwaves and also exceed some limitations of devices used in technical practice.Note that the antenna is the element for realizing a microwave imaging(MWI)system since...Metamaterials(MTM)can enhance the properties of microwaves and also exceed some limitations of devices used in technical practice.Note that the antenna is the element for realizing a microwave imaging(MWI)system since it is where signal transmission and absorption occur.Ultra-Wideband(UWB)antenna superstrates with MTM elements to ensure the signal transmitted from the antenna reaches the tumor and is absorbed by the same antenna.The lack of conventional head imaging techniques,for instance,Magnetic Resonance Imaging(MRI)and Computerized Tomography(CT)-scan,has been demonstrated in the paper focusing on the point of failure of these techniques for prompt diagnosis and portable systems.Furthermore,the importance ofMWIhas been addressed elaborately to portray its effectiveness and aptness for a primary tumor diagnosis.Other than that,MTM element designs have been discussed thoroughly based on their performances towards the contributions to the better image resolution of MWI with detailed reasonings.This paper proposes the novel design of a Zeroindex Split RingResonator(SRR)MTMelement superstrate with a UWB antenna implemented in MWI systems for detecting tumor.The novel design of the MTM enables the realization of a high gain of a superstrate UWB antenna with the highest gain of 5.70 dB.Besides that,the MTM imitates the conduct of the zeroreflection phase on the resonance frequency,which does not exist.An antenna with an MTM unit is of a 7×4 and 10×5 Zero-index SRR MTM element that acts as a superstrate plane to the antenna.Apart from that,Rogers(RT5880)substrate material is employed to fabricate the designed MTM unit cell,with the following characteristics:0.51mm thickness,the loss tangent of 0.02,as well as the relative permittivity of 2.2,with Computer Simulation Technology(CST)performing the simulation and design.Both MTM unit cells of 7×4 and 10×5 attained 0°with respect to the reflection phase at the 2.70 GHz frequency band.The first design,MTM Antenna Design 1,consists of a 7×4 MTM unit cell that observed a rise of 5.70 dB with a return loss(S11)−20.007 dB at 2.70 GHz frequency.The second design,MTM Antenna Design 2,consists of 10×5 MTM unit cells that recorded a gain of 5.66 dB,having the return loss(S11)−19.734 dB at 2.70 GHz frequency.Comparing these two MTM elements superstrates with the antenna,one can notice that the 7×4 MTM element shape has a low number of the unit cell with high gain and is a better choice than the 10×5 MTM element in realizing MTM element superstrates antenna for MWI.展开更多
As an emerging hybrid imaging modality,microwave-induced thermoacoustic imaging(MTAI),using microwaves as the excitation source and ultrasonic signals as the information carrier for combining the characteristics of hi...As an emerging hybrid imaging modality,microwave-induced thermoacoustic imaging(MTAI),using microwaves as the excitation source and ultrasonic signals as the information carrier for combining the characteristics of high contrast of electromagnetic imaging and high resolution of ultrasound imaging,has shown broad prospects in biomedical and clinical applications.The imaging contrast depends on the microwave-absorption coe±cient of the endogenous imaged tissue and the injected MTAI contrast agents.With systemically introduced functional nanoparticles,MTAI contrast and sensitivity can be further improved,and enables visualization of biological processes in vivo.In recent years,functional nanoparticles for MTAI have been developed to improve the performance and application range of MTAI in biomedical applications.This paper reviews the recent progress of functional nanoparticles for MTAI and their biomedical applications.The challenges and future directions of microwave thermoacoustic imaging with functional nanoparticles in theeld of translational medicine are discussed.展开更多
A tightly linked dual ring antenna is designed,and it is specifically tailored for uniformly coupling the microwave magnetic field to the nitrogen-vacancy(NV)center.The designed antenna operates at a center frequency ...A tightly linked dual ring antenna is designed,and it is specifically tailored for uniformly coupling the microwave magnetic field to the nitrogen-vacancy(NV)center.The designed antenna operates at a center frequency of about 2.87 GHz,with a bandwidth of around 200 MHz,allowing it to address multiple resonance peaks in the optically detected magnetic resonance(ODMR)spectrum in an external magnetic field.Moreover,the antenna generates a fairly uniform magnetic field in a range with a radius of 0.75 mm.High resolution imaging of the magnetic field distribution on the surface of the antenna is conducted by using a fiber diamond probe.We also investigate the effect of magnetic field uniformity on the linewidth of ODMR,so as to provide insights into reducing the inhomogeneous broadening of ODMR.展开更多
Sea surface temperature(SST)is a crucial physical parameter in meteorology and oceanography.This study demonstrates that the influence of earth incidence angle(EIA)on the SST retrieved from the microwave radiation ima...Sea surface temperature(SST)is a crucial physical parameter in meteorology and oceanography.This study demonstrates that the influence of earth incidence angle(EIA)on the SST retrieved from the microwave radiation imager(MWRI)onboard FengYun-3(FY-3)meteorological satellites should not be ignored.Compared with algorithms that do not consider the influence of EIA in the regression,those that integrate the EIA into the regression can enhance the accuracy of SST retrievals.Subsequently,based on the recalibrated Level 1B data from the FY-3/MWRI,a long-term SST dataset was reprocessed by employing the algorithm that integrates the EIA into the regression.The reprocessed SST data,including FY-3B/MWRI SST during 2010-2019,FY-3C/MWRI SST during 2013-2019,and FY-3D/MWRI SST during 2018-2020,were compared with the in-situ SST and the SST dataset from the Operational Sea Surface Temperature and Ice Analysis(OSTIA).The results show that the FY-3/MWRI SST data were consistent with both the in-situ SST and the OSTIA SST dataset.Compared with the Copernicus Climate Change Service V2.0 SST,the absolute deviation of the reprocessed SST,with a quality flag of 50,was less than 1.5℃.The root mean square errors of the FY-3/MWRI orbital,daily,and monthly SSTs,with a quality flag of 50,were approximately 0.82℃,0.69℃,and 0.37℃,respectively.The primary discrepancies between the FY-3/MWRI SST and the OSTIA SST were found mainly in the regions of the western boundary current and the Antarctic Circumpolar Current.Overall,this reprocessed SST product is recommended for El Niño and La Niña events monitoring.展开更多
China's FengYnn 3 (FY-3) polar orbiting satellites axe set to become an important sonrce of observational data for nu- merical weather prediction (NWP), atmospheric reanalyses, and climate monitoring studies over...China's FengYnn 3 (FY-3) polar orbiting satellites axe set to become an important sonrce of observational data for nu- merical weather prediction (NWP), atmospheric reanalyses, and climate monitoring studies over the next two decades. As part of the Climate Science for Service Partnership China (CSSP China) prograln, FY-3B Microwave Humidity Sounder 1 (MWHS-1) and FY-3C MWHS-2 observations have been thoroughly assessed and prepared for operational assimilation. This represents the first time observations from China's polar orbiting satellites have been used in the UK's global NWP model. Since 2016, continuous data quality monitoring has shown occasional bias changes found to be correlated to changes in the energy supply scheme regulating the platform heating system and other transient anomalies. Nonetheless, MWHS-1 and MWHS-2 significantly contribute to the 24-h forecast error reduction by 0.3% and 0.6%, respectively, and the combination of both instruments is shown to improve the fit to the model background of independent sounders by up to 1%. The observations from the Microwave Radiation Imager (MWRI) also are a potentially significant source of benefits for NWP models, but a solar-dependent bias observed in the instrument half-orbits has prevented their assimilation. This paper presents the bases of a correction scheme developed at the Met Office for the purpose of a future assimilation of MWRI data.展开更多
This work proposes a wideband and unidirectional antenna consisting of dual layer of coplanar waveguide based on the circular parasitic element technique.The design procedure is implemented in three stages:Design A,wh...This work proposes a wideband and unidirectional antenna consisting of dual layer of coplanar waveguide based on the circular parasitic element technique.The design procedure is implemented in three stages:Design A,which operates at 3.94 GHz with a bandwidth of 3.83 GHz and a fractional bandwidth(FBW)of 97.2%;Design B,which operates at 3.98 GHz with a bandwidth of 0.66 GHz(FBW of 56.53%);and Design C as the final antenna.The final Design C is designed to resonate at several frequencies between 2.89 and 7.0 GHz for microwave imaging applications with a bandwidth of 4.11 GHz(79.8%)centered at 5.15 GHz.This antenna is fabricated fully using two textile materials:felt as the substrate and ShieldIt as the conductor.It features a unidirectional radiation with a gain of 5.5 dBi,and reduced lowback radiation from 2.06 to−7.81 dB.The front-to-back ratio(FBR)for Design A,Design B and Design C are 4.82,2.94 and 11.36 dB,respectively.This antenna is wideband with unidirectional radiation,lightweight,and flexible.展开更多
To obtain some prior knowledge of breast cancer detection by microwave imaging, we have measured and analyzed the complex permittivity of tissues extracted from over 140 breast cancer surgeries. The relative permittiv...To obtain some prior knowledge of breast cancer detection by microwave imaging, we have measured and analyzed the complex permittivity of tissues extracted from over 140 breast cancer surgeries. The relative permittivity and conductivity of tumor at 1.6 GHz were 17.5% and 16.2% higher than those of mammary gland tissue, respectively. In invasive ductal carcinoma of scirrhous type, 8 out of 64 had higher relative permittivity and conductivity of mammary gland than those of tumor. However, when evaluated by the Debye parameter considering the frequency dependence of the tissue, it is rare that </span><i><span style="font-family:Verdana;">ε</span></i><sub><span style="font-family:Verdana;">∞</span></sub><span style="font-family:Verdana;"> and Δ</span><i><span style="font-family:Verdana;">ε</span></i><span style="font-family:Verdana;"> of cancer are simultaneously lower than those of mammary gland. The relative permittivity and conductivity of fibroadenoma are almost the same as those of mammary glands. The relative permittivity and conductivity of each tissue showed strong linearity. Microwave imaging requires accurate reconstruction of </span><i><span style="font-family:Verdana;">ε</span></i><sub><span style="font-family:Verdana;">∞</span></sub><span style="font-family:Verdana;"> and Δ</span><i><span style="font-family:Verdana;">ε</span></i><span style="font-family:Verdana;"> to distinguish cancer from normal tissue.展开更多
The simulation software, HFSS (high frequency structure simulator), is introduced in microwave oven design. In the cold test, a network analyzer is used to measure the reflection coefficient (S11) of the cavity un...The simulation software, HFSS (high frequency structure simulator), is introduced in microwave oven design. In the cold test, a network analyzer is used to measure the reflection coefficient (S11) of the cavity under empty and loaded states over the frequency range from 2.448 GHz to 2.468 GHz. In the hot test, a piece of wet thermal paper and an infrared thermal imaging camera are used to measure the electric field distributions on the mica and turntable. In the cold test, the simulation agrees well with the experiment no matter in empty state or loaded state. In the hot test, the simulation agrees well with the experiment in general in empty state and approximately in loaded state. The little difference in both cold and hot test may be due to that the model in simulation is not absolutely identical with that in experiment or the inadequate precision of infrared thermal imaging camera.展开更多
This paper reports the content of a lecture presented at the 1995 International Conference and Exhibition on Electronic Measurement and Instrumentation, held in Shanghai, China in 1995. The paper presents(thanks to th...This paper reports the content of a lecture presented at the 1995 International Conference and Exhibition on Electronic Measurement and Instrumentation, held in Shanghai, China in 1995. The paper presents(thanks to the courtesy of several scientists) some of the most significant results recently obtained in the field of short range microwave imaging. The overview concerns the research activity carried out in Europe and is focused on microwave imaging for non destructive testing, civil engineering, and scientific and medical applications. This type of imaging is characterized by a relatively short distance between the object to be detected and the probes.展开更多
In this paper, a collection of three-dimensional(3D)numerical breast models are developed based on clinical magnetic resonance images(MRIs). A hybrid contour detection method is used to create the contour, and the int...In this paper, a collection of three-dimensional(3D)numerical breast models are developed based on clinical magnetic resonance images(MRIs). A hybrid contour detection method is used to create the contour, and the internal space is filled with different breast tissues, with each corresponding to a specified interval of MRI pixel intensity. The developed models anatomically describe the complex tissue structure and dielectric properties in breasts. Besides, they are compatible with finite-difference-time-domain(FDTD)grid cells. Convolutional perfect matched layer(CPML)is applied in conjunction with FDTD to simulate the open boundary outside the model. In the test phase, microwave breast cancer detection simulations are performed in four models with varying radiographic densities. Then, confocal algorithm is utilized to reconstruct the tumor images. Imaging results show that the tumor voxels can be recognized in every case, with 2 mm location error in two low density cases and 7 mm─8 mm location errors in two high density cases, demonstrating that the MRI-derived models can characterize the individual difference between patients' breasts.展开更多
This study investigated the ability of microwave holography to accurately reconstruct the tissue structure of the human body. Numerical breast and head phantoms were imaged by 3D near-field holography using backscatte...This study investigated the ability of microwave holography to accurately reconstruct the tissue structure of the human body. Numerical breast and head phantoms were imaged by 3D near-field holography using backscattered waves obtained by a monostatic planar scan. Complex organizational structures have been reconstructed accurately and quickly. In addition, breasts with relatively simple histology could be reconstructed without the matching liquid.展开更多
A technique for estimating tropical cyclone(TC) intensity over the Western North Pacific utilizing FY-3Microwave Imager(MWRI) data is developed. As a first step, we investigated the relationship between the FY-3 MWRI ...A technique for estimating tropical cyclone(TC) intensity over the Western North Pacific utilizing FY-3Microwave Imager(MWRI) data is developed. As a first step, we investigated the relationship between the FY-3 MWRI brightness temperature(TB) parameters, which are computed in concentric circles or annuli of different radius in different MWRI frequencies, and the TC maximum wind speed(Vmax) from the TC best track data. We found that the parameters of lower frequency channels' minimum TB, mean TB and ratio of pixels over the threshold TB with a radius of 1.0 or 1.5 degrees from the center give higher correlation. Then by applying principal components analysis(PCA)and multiple regression method, we established an estimation model and evaluated it using independent verification data, with the RMSE being 13 kt. The estimated Vmax is always stronger in the early stages of development, but slightly weaker toward the mature stage, and a reversal of positive and negative bias takes place with a boundary of around 70 kt. For the TC that has a larger error, we found that they are often with less organized and asymmetric cloud pattern, so the classification of TC cloud pattern will help improve the acuracy of the estimated TC intensity, and with the increase of statistical samples the accuracy of the estimated TC intensity will also be improved.展开更多
Satellite-derived sea surface temperatures(SSTs) from the tropical rainfall measuring mission(TRMM)microwave imager(TMI) and the advanced microwave scanning radiometer for the earth observing system(AMSR-E) we...Satellite-derived sea surface temperatures(SSTs) from the tropical rainfall measuring mission(TRMM)microwave imager(TMI) and the advanced microwave scanning radiometer for the earth observing system(AMSR-E) were compared with non-pumped near-surface temperatures(NSTs) obtained from Argo profiling floats over the global oceans. Factors that might cause temperature differences were examined, including wind speed, columnar water vapor, liquid cloud water, and geographic location. The results show that both TMI and AMSR-E SSTs are highly correlated with the Argo NSTs; however, at low wind speeds, they are on average warmer than the Argo NSTs. The TMI performs slightly better than the AMSR-E at low wind speeds, whereas the TMI SST retrievals might be poorly calibrated at high wind speeds. The temperature differences indicate a warm bias of the TMI/AMSR-E when columnar water vapor is low, which can indicate that neither TMI nor AMSR-E SSTs are well calibrated at high latitudes. The SST in the Kuroshio Extension region has higher variability than in the Kuroshio region. The variability of the temperature difference between the satellite-retrieved SSTs and the Argo NSTs is lower in the Kuroshio Extension during spring. At low wind speeds, neither TMI nor AMSR-E SSTs are well calibrated, although the TMI performs better than the AMSR-E.展开更多
Microwave Radiometer Imager(MWRI) is a key payload of China’s second generation polar meteorological satellite, i.e., Fengyun-3 series(FY-3). Up to now, 5 satellites including FY-3A(2008), FY-3B(2010), FY-3C(2013), F...Microwave Radiometer Imager(MWRI) is a key payload of China’s second generation polar meteorological satellite, i.e., Fengyun-3 series(FY-3). Up to now, 5 satellites including FY-3A(2008), FY-3B(2010), FY-3C(2013), FY-3D(2018), and FY-3E(2021) have been launched successfully to provide multiwavelength, all-weather, and global data for decades. Much progress has been made on the calibration of MWRI and a recalibrated MWRI brightness temperature(BT) product(V2) was recently released. This study thoroughly evaluates the accuracy of this new product from FY-3B, 3C, and 3D by using the simultaneous collocated Global Precipitation Measurement(GPM)Microwave Imager(GMI) measurements as a reference. The results show that the mean biases(MBEs) of the BT between MWRI and GMI are generally less than 0.5 K and the root mean squares(RMSs) between them are less than1.5 K. The previous notable ascending and descending difference of the MWRI has disappeared. This indicates that the new MWRI recalibration procedure is very effective in removing potential errors associated with the emission of the hot-load reflector. Analysis of the dependence of MBE on the latitude and earth scene temperature shows that MBE decreases with decreasing latitude over ocean. Furthermore, MBE over ocean decreases linearly with increasing scene temperature for almost all channels, whereas this does not occur over land. A linear regression fitting is then used to modify MWRI, which can reduce the MBE over ocean to be within 0.2 K. The standard deviation of error of GMI, FY-3B, and FY-3D MWRI BT data derived by using the three-cornered hat method(TCH) shows that GMI has the best overall performance over ocean except at 10.65 GHz where its standard deviation of error is slightly larger than that of FY-3D. Over land, the standard deviation of error of FY-3D is the lowest at almost all channels except at 89V. MWRI onboard FY-3 series satellites would serve as an important passive microwave radiometer member of the constellation to monitor key surface and atmospheric properties.展开更多
A summer-time shipboard meteorological survey is described in the Northwest Indian Ocean. Shipboard observations are used to evaluate a satellite-based sea surface temperature(SST), and then find the main factors th...A summer-time shipboard meteorological survey is described in the Northwest Indian Ocean. Shipboard observations are used to evaluate a satellite-based sea surface temperature(SST), and then find the main factors that are highly correlated with errors. Two satellite data, the first is remote sensing product of a microwave, which is a Tropical Rainfall Measuring Mission Microwave Imager(TMI), and the second is merged data from the microwave and infrared satellite as well as drifter observations, which is Operational Sea Surface Temperature and Sea Ice Analysis(OSTIA). The results reveal that the daily mean SST of merged data has much lower bias and root mean square error as compared with that from microwave products. Therefore the results support the necessary of the merging infrared and drifter SST with a microwave satellite for improving the quality of the SST. Furthermore, the correlation coefficient between an SST error and meteorological parameters, which include a wind speed, an air temperature, a relative humidity, an air pressure, and a visibility. The results show that the wind speed has the largest correlation coefficient with the TMI SST error. However, the air temperature is the most important factor to the OSTIA SST error. Meanwhile,the relative humidity shows the high correlation with the SST error for the OSTIA product.展开更多
Satellite microwave instruments have different field of views(FOVs)in different channels.A direct average technique(“direct method”)is frequently used to generate gridded datasets in the earth science community.A la...Satellite microwave instruments have different field of views(FOVs)in different channels.A direct average technique(“direct method”)is frequently used to generate gridded datasets in the earth science community.A large FOV will measure radiance from outside the area of a designated grid cell.Thus,the direct method will lead to errors in a measurement over a grid cell because some pixels covering areas outside of the cell are involved in the averaging process.The Backus−Gilbert method(BG method)is proposed and demonstrated to minimize those uncertainties.Three sampling resolutions(6.5 km×6.0 km,11.5 km×6.0 km,13.0 km×6.0 km)are analyzed based on the scanning characteristics of the Global Precipitation Measurement(GPM)Microwave Imager(GMI)18.9-GHz channel.Brightness temperatures(TBs)at 0.5 km×0.5 km resolution over eastern China are used to obtain synthetic 18.9-GHz TBs at the three sampling resolutions.The direct and BG methods are both applied to create a 25 km×25 km gridded dataset and their related uncertainties are analyzed.Results indicate the error variances with the direct method are 3.00,3.68 and 4.99 K2 at the three sampling resolutions,respectively.By contrast,the BG method leads to a much smaller error variance than the direct method,especially over areas with a large TB gradient.Two GMI orbital measurements are applied to verify the BG method for gridding process is reliable.The BG method could be utilized for general purpose of creating a gridded dataset.展开更多
The Microwave Radiation Imager (MWRI) on board Chinese Fengyun-3 (FY-3) satellites provides measurements at 10.65, 18.7, 23.8, 36.5, and 89.0 GHz with both horizontal and vertical polarization channels. Brightness...The Microwave Radiation Imager (MWRI) on board Chinese Fengyun-3 (FY-3) satellites provides measurements at 10.65, 18.7, 23.8, 36.5, and 89.0 GHz with both horizontal and vertical polarization channels. Brightness temperature measurements of those channels with their central frequencies higher than 19 GHz from satellite-based microwave imager radiometers had traditionally been used to retrieve cloud liquid water path (LWP) over ocean. The results show that the lowest frequency channels are the most appropriate for retrieving LWP when its values are large. Therefore, a modified LWP retrieval algorithm is developed for retrieving LWP of different magnitudes involving not only the high frequency channels but also the lowest frequency channels of FY-3 MWRI. The theoretical estimates of the LWP retrieval errors are between 0.11 and 0.06 mm for 10.65- and 18.7-GHz channels and between 0.02 and 0.04 mm for 36.5- and 89.0-GHz channels. It is also shown that the brightness temperature observations at 10.65 GHz can be utilized to better retrieve the LWP greater than 3 mm in the eyewall region of Super Typhoon Neoguri (2014). The spiral structure of clouds within and around Typhoon Neoguri can be well captured by combining the LWP retrievals from different frequency channels.展开更多
基金the Chinese National Natural Science Foundation of China(G41805016)the Chinese National Key R&D Program of China(2018YFC1506404)+3 种基金the Chinese National Natural Science Founda-tion of China(G41805070)the Chinese National Key R&D Program of China(2018YFC1506603)the research project of Heavy Rain and Drought-Flood Disasters in Plateau and Basin Key Laboratory of Sichuan Province in China(SZKT201901,SZKT201904)the research project of the Institute of Atmospheric Environment,China Meteorological Administration,Shenyang in China(2020SYIAE07,2020SYIAE02)。
文摘The impact of assimilating radiance data from the advanced satellite sensor GMI(GPM microwave imager)for typhoon analyses and forecasts was investigated using both a three-dimensional variational(3DVAR)and a hybrid ensemble-3DVAR method.The interface of assimilating the radiance for the sensor GMI was established in the Weather Research and Forecasting(WRF)model.The GMI radiance data are assimilated for Typhoon Matmo(2014),Typhoon Chan-hom(2015),Typhoon Meranti(2016),and Typhoon Mangkhut(2018)in the Pacific before their landing.The results show that after assimilating the GMI radiance data under clear sky condition with the 3DVAR method,the wind,temperature,and humidity fields are effectively adjusted,leading to improved forecast skills of the typhoon track with GMI radiance assimilation.The hybrid DA method is able to further adjust the location of the typhoon systematically.The improvement of the track forecast is even more obvious for later forecast periods.In addition,water vapor and hydrometeors are enhanced to some extent,especially with the hybrid method.
基金supported by the National Magnetic Confinement Fusion Energy Program of China(No.2019YFE03020001)the Collaborative Innovation Program of Hefei Science Center,CAS(No.2021HSC-CIP010)the Fundamental Research Funds for the Central Universities。
文摘Interpreting experimental diagnostics data in tokamaks,while considering non-ideal effects,is challenging due to the complexity of plasmas.To address this challenge,a general synthetic diagnostics(GSD)platform has been established that facilitates microwave imaging reflectometry and electron cyclotron emission imaging.This platform utilizes plasma profiles as input and incorporates the finite-difference time domain,ray tracing and the radiative transfer equation to calculate the propagation of plasma spontaneous radiation and the external electromagnetic field in plasmas.Benchmark tests for classical cases have been conducted to verify the accuracy of every core module in the GSD platform.Finally,2D imaging of a typical electron temperature distribution is reproduced by this platform and the results are consistent with the given real experimental data.This platform also has the potential to be extended to 3D electromagnetic field simulations and other microwave diagnostics such as cross-polarization scattering.
文摘The ability of the Tropical Rainfall Measuring Mission Microwave Imager(TRMM/TMI)for cloud liquid water(CLW)retrieval has been demonstrated in this study.Due to the great sensitivity of the TMI 85.5 GHz channels to CLW,the liquid water path(LWP)of nonprecipitating clouds over land can be successfully estimated using the VDISORT model based on the iteration steps.Both the vertical-polarized 85. 5 GHz single-channel method and the polarization-difference of 85.5 GHz method were applied to the LWP estimates over land regions during the Huaihe River Basin Energy and Water Cycle Experiment(HUBEX)in China.The retrieval results show reasonable agreement with the ground-based microwave radiometer measurements.When the surface emissivity or skin temperature is difficult to be made sure,the polarization-difference method shows advantages of providing estimates of LWP especially for low clouds because of its extremely insensitiveness to the surface skin temperature.
基金the Fundamental Research Grant Scheme (FRGS/1/2018/ICT06/UNIMAP/02/1)of the Ministry of Higher Education of Malaysia.
文摘Metamaterials(MTM)can enhance the properties of microwaves and also exceed some limitations of devices used in technical practice.Note that the antenna is the element for realizing a microwave imaging(MWI)system since it is where signal transmission and absorption occur.Ultra-Wideband(UWB)antenna superstrates with MTM elements to ensure the signal transmitted from the antenna reaches the tumor and is absorbed by the same antenna.The lack of conventional head imaging techniques,for instance,Magnetic Resonance Imaging(MRI)and Computerized Tomography(CT)-scan,has been demonstrated in the paper focusing on the point of failure of these techniques for prompt diagnosis and portable systems.Furthermore,the importance ofMWIhas been addressed elaborately to portray its effectiveness and aptness for a primary tumor diagnosis.Other than that,MTM element designs have been discussed thoroughly based on their performances towards the contributions to the better image resolution of MWI with detailed reasonings.This paper proposes the novel design of a Zeroindex Split RingResonator(SRR)MTMelement superstrate with a UWB antenna implemented in MWI systems for detecting tumor.The novel design of the MTM enables the realization of a high gain of a superstrate UWB antenna with the highest gain of 5.70 dB.Besides that,the MTM imitates the conduct of the zeroreflection phase on the resonance frequency,which does not exist.An antenna with an MTM unit is of a 7×4 and 10×5 Zero-index SRR MTM element that acts as a superstrate plane to the antenna.Apart from that,Rogers(RT5880)substrate material is employed to fabricate the designed MTM unit cell,with the following characteristics:0.51mm thickness,the loss tangent of 0.02,as well as the relative permittivity of 2.2,with Computer Simulation Technology(CST)performing the simulation and design.Both MTM unit cells of 7×4 and 10×5 attained 0°with respect to the reflection phase at the 2.70 GHz frequency band.The first design,MTM Antenna Design 1,consists of a 7×4 MTM unit cell that observed a rise of 5.70 dB with a return loss(S11)−20.007 dB at 2.70 GHz frequency.The second design,MTM Antenna Design 2,consists of 10×5 MTM unit cells that recorded a gain of 5.66 dB,having the return loss(S11)−19.734 dB at 2.70 GHz frequency.Comparing these two MTM elements superstrates with the antenna,one can notice that the 7×4 MTM element shape has a low number of the unit cell with high gain and is a better choice than the 10×5 MTM element in realizing MTM element superstrates antenna for MWI.
基金This research was supported by the National Natural Science Foundation of China(62075066)the Science and Technology Planning Project of Guangdong Province,China(2019A1515012054)+2 种基金the Science and Technology Program of Guangzhou(2019050001)the Science and Technology Program of Guangzhou(202201010718)the Key-Area Research and Development Program of Guangdong Province(2019B030335001).
文摘As an emerging hybrid imaging modality,microwave-induced thermoacoustic imaging(MTAI),using microwaves as the excitation source and ultrasonic signals as the information carrier for combining the characteristics of high contrast of electromagnetic imaging and high resolution of ultrasound imaging,has shown broad prospects in biomedical and clinical applications.The imaging contrast depends on the microwave-absorption coe±cient of the endogenous imaged tissue and the injected MTAI contrast agents.With systemically introduced functional nanoparticles,MTAI contrast and sensitivity can be further improved,and enables visualization of biological processes in vivo.In recent years,functional nanoparticles for MTAI have been developed to improve the performance and application range of MTAI in biomedical applications.This paper reviews the recent progress of functional nanoparticles for MTAI and their biomedical applications.The challenges and future directions of microwave thermoacoustic imaging with functional nanoparticles in theeld of translational medicine are discussed.
基金Project supported by the National Key Research and Development Program of China(Grant No.2021YFB2012600)the Shanghai Aerospace Science and Technology Innovation Fund(Grant No.SAST-2022-102).
文摘A tightly linked dual ring antenna is designed,and it is specifically tailored for uniformly coupling the microwave magnetic field to the nitrogen-vacancy(NV)center.The designed antenna operates at a center frequency of about 2.87 GHz,with a bandwidth of around 200 MHz,allowing it to address multiple resonance peaks in the optically detected magnetic resonance(ODMR)spectrum in an external magnetic field.Moreover,the antenna generates a fairly uniform magnetic field in a range with a radius of 0.75 mm.High resolution imaging of the magnetic field distribution on the surface of the antenna is conducted by using a fiber diamond probe.We also investigate the effect of magnetic field uniformity on the linewidth of ODMR,so as to provide insights into reducing the inhomogeneous broadening of ODMR.
基金National Natural Science Foundation of China(42330602)Youth Innovation Team for“FengYun Satellite Remote Sensing Product Verification”(CMA2023QN12)。
文摘Sea surface temperature(SST)is a crucial physical parameter in meteorology and oceanography.This study demonstrates that the influence of earth incidence angle(EIA)on the SST retrieved from the microwave radiation imager(MWRI)onboard FengYun-3(FY-3)meteorological satellites should not be ignored.Compared with algorithms that do not consider the influence of EIA in the regression,those that integrate the EIA into the regression can enhance the accuracy of SST retrievals.Subsequently,based on the recalibrated Level 1B data from the FY-3/MWRI,a long-term SST dataset was reprocessed by employing the algorithm that integrates the EIA into the regression.The reprocessed SST data,including FY-3B/MWRI SST during 2010-2019,FY-3C/MWRI SST during 2013-2019,and FY-3D/MWRI SST during 2018-2020,were compared with the in-situ SST and the SST dataset from the Operational Sea Surface Temperature and Ice Analysis(OSTIA).The results show that the FY-3/MWRI SST data were consistent with both the in-situ SST and the OSTIA SST dataset.Compared with the Copernicus Climate Change Service V2.0 SST,the absolute deviation of the reprocessed SST,with a quality flag of 50,was less than 1.5℃.The root mean square errors of the FY-3/MWRI orbital,daily,and monthly SSTs,with a quality flag of 50,were approximately 0.82℃,0.69℃,and 0.37℃,respectively.The primary discrepancies between the FY-3/MWRI SST and the OSTIA SST were found mainly in the regions of the western boundary current and the Antarctic Circumpolar Current.Overall,this reprocessed SST product is recommended for El Niño and La Niña events monitoring.
基金supported by the UK-China Research&Innovation Partnership Fund through the Met Office Climate Science for Service Partnership(CSSP)China as part of the Newton Fund
文摘China's FengYnn 3 (FY-3) polar orbiting satellites axe set to become an important sonrce of observational data for nu- merical weather prediction (NWP), atmospheric reanalyses, and climate monitoring studies over the next two decades. As part of the Climate Science for Service Partnership China (CSSP China) prograln, FY-3B Microwave Humidity Sounder 1 (MWHS-1) and FY-3C MWHS-2 observations have been thoroughly assessed and prepared for operational assimilation. This represents the first time observations from China's polar orbiting satellites have been used in the UK's global NWP model. Since 2016, continuous data quality monitoring has shown occasional bias changes found to be correlated to changes in the energy supply scheme regulating the platform heating system and other transient anomalies. Nonetheless, MWHS-1 and MWHS-2 significantly contribute to the 24-h forecast error reduction by 0.3% and 0.6%, respectively, and the combination of both instruments is shown to improve the fit to the model background of independent sounders by up to 1%. The observations from the Microwave Radiation Imager (MWRI) also are a potentially significant source of benefits for NWP models, but a solar-dependent bias observed in the instrument half-orbits has prevented their assimilation. This paper presents the bases of a correction scheme developed at the Met Office for the purpose of a future assimilation of MWRI data.
基金This work was supported in part by the Malaysia Public Service Department(JPA)and Universiti Teknikal Malaysia Melaka(UTeM)under Jurnal/2020/FKEKK/Q00053P.J.Soh acknowledges the support from the Academy of Finland 6 Genesis Flagship(Grant No.318927).
文摘This work proposes a wideband and unidirectional antenna consisting of dual layer of coplanar waveguide based on the circular parasitic element technique.The design procedure is implemented in three stages:Design A,which operates at 3.94 GHz with a bandwidth of 3.83 GHz and a fractional bandwidth(FBW)of 97.2%;Design B,which operates at 3.98 GHz with a bandwidth of 0.66 GHz(FBW of 56.53%);and Design C as the final antenna.The final Design C is designed to resonate at several frequencies between 2.89 and 7.0 GHz for microwave imaging applications with a bandwidth of 4.11 GHz(79.8%)centered at 5.15 GHz.This antenna is fabricated fully using two textile materials:felt as the substrate and ShieldIt as the conductor.It features a unidirectional radiation with a gain of 5.5 dBi,and reduced lowback radiation from 2.06 to−7.81 dB.The front-to-back ratio(FBR)for Design A,Design B and Design C are 4.82,2.94 and 11.36 dB,respectively.This antenna is wideband with unidirectional radiation,lightweight,and flexible.
文摘To obtain some prior knowledge of breast cancer detection by microwave imaging, we have measured and analyzed the complex permittivity of tissues extracted from over 140 breast cancer surgeries. The relative permittivity and conductivity of tumor at 1.6 GHz were 17.5% and 16.2% higher than those of mammary gland tissue, respectively. In invasive ductal carcinoma of scirrhous type, 8 out of 64 had higher relative permittivity and conductivity of mammary gland than those of tumor. However, when evaluated by the Debye parameter considering the frequency dependence of the tissue, it is rare that </span><i><span style="font-family:Verdana;">ε</span></i><sub><span style="font-family:Verdana;">∞</span></sub><span style="font-family:Verdana;"> and Δ</span><i><span style="font-family:Verdana;">ε</span></i><span style="font-family:Verdana;"> of cancer are simultaneously lower than those of mammary gland. The relative permittivity and conductivity of fibroadenoma are almost the same as those of mammary glands. The relative permittivity and conductivity of each tissue showed strong linearity. Microwave imaging requires accurate reconstruction of </span><i><span style="font-family:Verdana;">ε</span></i><sub><span style="font-family:Verdana;">∞</span></sub><span style="font-family:Verdana;"> and Δ</span><i><span style="font-family:Verdana;">ε</span></i><span style="font-family:Verdana;"> to distinguish cancer from normal tissue.
基金supported by the National Natural Science Foundation of China under Grant No.10775029Vacuum Electronics National Laboratory Foundation under Grant No. NKLC001-063Postdoctoral Foundation under Grant No.20070411149
文摘The simulation software, HFSS (high frequency structure simulator), is introduced in microwave oven design. In the cold test, a network analyzer is used to measure the reflection coefficient (S11) of the cavity under empty and loaded states over the frequency range from 2.448 GHz to 2.468 GHz. In the hot test, a piece of wet thermal paper and an infrared thermal imaging camera are used to measure the electric field distributions on the mica and turntable. In the cold test, the simulation agrees well with the experiment no matter in empty state or loaded state. In the hot test, the simulation agrees well with the experiment in general in empty state and approximately in loaded state. The little difference in both cold and hot test may be due to that the model in simulation is not absolutely identical with that in experiment or the inadequate precision of infrared thermal imaging camera.
文摘This paper reports the content of a lecture presented at the 1995 International Conference and Exhibition on Electronic Measurement and Instrumentation, held in Shanghai, China in 1995. The paper presents(thanks to the courtesy of several scientists) some of the most significant results recently obtained in the field of short range microwave imaging. The overview concerns the research activity carried out in Europe and is focused on microwave imaging for non destructive testing, civil engineering, and scientific and medical applications. This type of imaging is characterized by a relatively short distance between the object to be detected and the probes.
基金Supported by the National Natural Science Foundation of China(No.61271323)
文摘In this paper, a collection of three-dimensional(3D)numerical breast models are developed based on clinical magnetic resonance images(MRIs). A hybrid contour detection method is used to create the contour, and the internal space is filled with different breast tissues, with each corresponding to a specified interval of MRI pixel intensity. The developed models anatomically describe the complex tissue structure and dielectric properties in breasts. Besides, they are compatible with finite-difference-time-domain(FDTD)grid cells. Convolutional perfect matched layer(CPML)is applied in conjunction with FDTD to simulate the open boundary outside the model. In the test phase, microwave breast cancer detection simulations are performed in four models with varying radiographic densities. Then, confocal algorithm is utilized to reconstruct the tumor images. Imaging results show that the tumor voxels can be recognized in every case, with 2 mm location error in two low density cases and 7 mm─8 mm location errors in two high density cases, demonstrating that the MRI-derived models can characterize the individual difference between patients' breasts.
文摘This study investigated the ability of microwave holography to accurately reconstruct the tissue structure of the human body. Numerical breast and head phantoms were imaged by 3D near-field holography using backscattered waves obtained by a monostatic planar scan. Complex organizational structures have been reconstructed accurately and quickly. In addition, breasts with relatively simple histology could be reconstructed without the matching liquid.
基金National Key Research and Development Program of China(2016YFA0600101)National Basic Research Program of China(973 Program,2010CB950802)National Natural Science Fund(41605028)
文摘A technique for estimating tropical cyclone(TC) intensity over the Western North Pacific utilizing FY-3Microwave Imager(MWRI) data is developed. As a first step, we investigated the relationship between the FY-3 MWRI brightness temperature(TB) parameters, which are computed in concentric circles or annuli of different radius in different MWRI frequencies, and the TC maximum wind speed(Vmax) from the TC best track data. We found that the parameters of lower frequency channels' minimum TB, mean TB and ratio of pixels over the threshold TB with a radius of 1.0 or 1.5 degrees from the center give higher correlation. Then by applying principal components analysis(PCA)and multiple regression method, we established an estimation model and evaluated it using independent verification data, with the RMSE being 13 kt. The estimated Vmax is always stronger in the early stages of development, but slightly weaker toward the mature stage, and a reversal of positive and negative bias takes place with a boundary of around 70 kt. For the TC that has a larger error, we found that they are often with less organized and asymmetric cloud pattern, so the classification of TC cloud pattern will help improve the acuracy of the estimated TC intensity, and with the increase of statistical samples the accuracy of the estimated TC intensity will also be improved.
基金The National Basic Research Program(973 Program)of China under contract No.2013CB430301the National Natural Science Foundation of China under contract Nos 41440039,41206022 and 41406022the Public Science and Technology Research Funds Projects of Ocean under contract No.201305032
文摘Satellite-derived sea surface temperatures(SSTs) from the tropical rainfall measuring mission(TRMM)microwave imager(TMI) and the advanced microwave scanning radiometer for the earth observing system(AMSR-E) were compared with non-pumped near-surface temperatures(NSTs) obtained from Argo profiling floats over the global oceans. Factors that might cause temperature differences were examined, including wind speed, columnar water vapor, liquid cloud water, and geographic location. The results show that both TMI and AMSR-E SSTs are highly correlated with the Argo NSTs; however, at low wind speeds, they are on average warmer than the Argo NSTs. The TMI performs slightly better than the AMSR-E at low wind speeds, whereas the TMI SST retrievals might be poorly calibrated at high wind speeds. The temperature differences indicate a warm bias of the TMI/AMSR-E when columnar water vapor is low, which can indicate that neither TMI nor AMSR-E SSTs are well calibrated at high latitudes. The SST in the Kuroshio Extension region has higher variability than in the Kuroshio region. The variability of the temperature difference between the satellite-retrieved SSTs and the Argo NSTs is lower in the Kuroshio Extension during spring. At low wind speeds, neither TMI nor AMSR-E SSTs are well calibrated, although the TMI performs better than the AMSR-E.
基金National Natural Science Foundation of China (42030608 and 42075079)。
文摘Microwave Radiometer Imager(MWRI) is a key payload of China’s second generation polar meteorological satellite, i.e., Fengyun-3 series(FY-3). Up to now, 5 satellites including FY-3A(2008), FY-3B(2010), FY-3C(2013), FY-3D(2018), and FY-3E(2021) have been launched successfully to provide multiwavelength, all-weather, and global data for decades. Much progress has been made on the calibration of MWRI and a recalibrated MWRI brightness temperature(BT) product(V2) was recently released. This study thoroughly evaluates the accuracy of this new product from FY-3B, 3C, and 3D by using the simultaneous collocated Global Precipitation Measurement(GPM)Microwave Imager(GMI) measurements as a reference. The results show that the mean biases(MBEs) of the BT between MWRI and GMI are generally less than 0.5 K and the root mean squares(RMSs) between them are less than1.5 K. The previous notable ascending and descending difference of the MWRI has disappeared. This indicates that the new MWRI recalibration procedure is very effective in removing potential errors associated with the emission of the hot-load reflector. Analysis of the dependence of MBE on the latitude and earth scene temperature shows that MBE decreases with decreasing latitude over ocean. Furthermore, MBE over ocean decreases linearly with increasing scene temperature for almost all channels, whereas this does not occur over land. A linear regression fitting is then used to modify MWRI, which can reduce the MBE over ocean to be within 0.2 K. The standard deviation of error of GMI, FY-3B, and FY-3D MWRI BT data derived by using the three-cornered hat method(TCH) shows that GMI has the best overall performance over ocean except at 10.65 GHz where its standard deviation of error is slightly larger than that of FY-3D. Over land, the standard deviation of error of FY-3D is the lowest at almost all channels except at 89V. MWRI onboard FY-3 series satellites would serve as an important passive microwave radiometer member of the constellation to monitor key surface and atmospheric properties.
基金China Ocean Mineral Resources Research and Development Association Project under contract No.DY125-12-R-03the National Natural Science Foundation of China under contract Nos 41476021 and 41321004the Scientific Research Fund of Second Institute of Oceanography,State Oceanic Administration China under contract No.JT1205
文摘A summer-time shipboard meteorological survey is described in the Northwest Indian Ocean. Shipboard observations are used to evaluate a satellite-based sea surface temperature(SST), and then find the main factors that are highly correlated with errors. Two satellite data, the first is remote sensing product of a microwave, which is a Tropical Rainfall Measuring Mission Microwave Imager(TMI), and the second is merged data from the microwave and infrared satellite as well as drifter observations, which is Operational Sea Surface Temperature and Sea Ice Analysis(OSTIA). The results reveal that the daily mean SST of merged data has much lower bias and root mean square error as compared with that from microwave products. Therefore the results support the necessary of the merging infrared and drifter SST with a microwave satellite for improving the quality of the SST. Furthermore, the correlation coefficient between an SST error and meteorological parameters, which include a wind speed, an air temperature, a relative humidity, an air pressure, and a visibility. The results show that the wind speed has the largest correlation coefficient with the TMI SST error. However, the air temperature is the most important factor to the OSTIA SST error. Meanwhile,the relative humidity shows the high correlation with the SST error for the OSTIA product.
基金This study was supported by the National Key R&D Program of China(Grant Nos.2018YFC1507200 and 2017YFC1501402)the Second Tibetan Plateau Scientific Expedition and Research(STEP)program(Grant No.2019QZKK0104)+1 种基金an NSFC Project(Grant Nos.91837310,41675041,and 41620104009)the Key Research and Development Projects in Anhui Province(Grant No.201904a07020099),and CLIMATE-TPE(ID 32070)under the framework of the ESA-MOST Dragon 4 program.
文摘Satellite microwave instruments have different field of views(FOVs)in different channels.A direct average technique(“direct method”)is frequently used to generate gridded datasets in the earth science community.A large FOV will measure radiance from outside the area of a designated grid cell.Thus,the direct method will lead to errors in a measurement over a grid cell because some pixels covering areas outside of the cell are involved in the averaging process.The Backus−Gilbert method(BG method)is proposed and demonstrated to minimize those uncertainties.Three sampling resolutions(6.5 km×6.0 km,11.5 km×6.0 km,13.0 km×6.0 km)are analyzed based on the scanning characteristics of the Global Precipitation Measurement(GPM)Microwave Imager(GMI)18.9-GHz channel.Brightness temperatures(TBs)at 0.5 km×0.5 km resolution over eastern China are used to obtain synthetic 18.9-GHz TBs at the three sampling resolutions.The direct and BG methods are both applied to create a 25 km×25 km gridded dataset and their related uncertainties are analyzed.Results indicate the error variances with the direct method are 3.00,3.68 and 4.99 K2 at the three sampling resolutions,respectively.By contrast,the BG method leads to a much smaller error variance than the direct method,especially over areas with a large TB gradient.Two GMI orbital measurements are applied to verify the BG method for gridding process is reliable.The BG method could be utilized for general purpose of creating a gridded dataset.
基金Supported by the National Natural Science Foundation of China(91337218 and 41475103)China Meteorological Administration Special Public Welfare Research Fund(GYHY201406008)
文摘The Microwave Radiation Imager (MWRI) on board Chinese Fengyun-3 (FY-3) satellites provides measurements at 10.65, 18.7, 23.8, 36.5, and 89.0 GHz with both horizontal and vertical polarization channels. Brightness temperature measurements of those channels with their central frequencies higher than 19 GHz from satellite-based microwave imager radiometers had traditionally been used to retrieve cloud liquid water path (LWP) over ocean. The results show that the lowest frequency channels are the most appropriate for retrieving LWP when its values are large. Therefore, a modified LWP retrieval algorithm is developed for retrieving LWP of different magnitudes involving not only the high frequency channels but also the lowest frequency channels of FY-3 MWRI. The theoretical estimates of the LWP retrieval errors are between 0.11 and 0.06 mm for 10.65- and 18.7-GHz channels and between 0.02 and 0.04 mm for 36.5- and 89.0-GHz channels. It is also shown that the brightness temperature observations at 10.65 GHz can be utilized to better retrieve the LWP greater than 3 mm in the eyewall region of Super Typhoon Neoguri (2014). The spiral structure of clouds within and around Typhoon Neoguri can be well captured by combining the LWP retrievals from different frequency channels.