- 标题
- 摘要
- 关键词
- 实验方案
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[IEEE 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Chicago, IL, USA (2019.6.16-2019.6.21)] 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - An analysis of Passivated emitter and rear contact (PERC) cell and module
摘要： A synergetic approach for the estimation of stable boundary layer height (SBLH) using lidar and microwave radiometer (MWR) data is presented. Vertical variance of the backscatter signal from a ceilometer is used as an indicator of the aerosol stratification in the nocturnal stable boundary layer. This hypothesis is supported by a statistical analysis over one month of observations. Thermodynamic information from the MWR-derived potential temperature is incorporated as coarse estimate of the SBLH. Data from the two instruments are adaptively assimilated by using an extended Kalman filter (EKF). A first test of the algorithm is performed by applying it to collocated Vaisala CT25K ceilometer and humidity and temperature profiler MWR data collected during the HD(CP)2 Observational Prototype Experiment (HOPE) campaign at Jülich, Germany. The application of the algorithm to different atmospheric scenarios reveals the superior performance of the EKF compared to a nonlinear least squares estimator, particularly in nonidealized conditions.
关键词： signal processing,Adaptive Kalman filtering,microwave radiometry,remote sensing,laser radar
更新于2025-09-23 15:19:57
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[IEEE 2019 PhotonIcs & Electromagnetics Research Symposium - Spring (PIERS-Spring) - Rome, Italy (2019.6.17-2019.6.20)] 2019 PhotonIcs & Electromagnetics Research Symposium - Spring (PIERS-Spring) - Robust GaN Limiting LNA for C-Ku Band T/R Modules
摘要： A synergetic approach for the estimation of stable boundary layer height (SBLH) using lidar and microwave radiometer (MWR) data is presented. Vertical variance of the backscatter signal from a ceilometer is used as an indicator of the aerosol stratification in the nocturnal stable boundary layer. This hypothesis is supported by a statistical analysis over one month of observations. Thermodynamic information from the MWR-derived potential temperature is incorporated as coarse estimate of the SBLH. Data from the two instruments are adaptively assimilated by using an extended Kalman filter (EKF). A first test of the algorithm is performed by applying it to collocated Vaisala CT25K ceilometer and humidity and temperature profiler MWR data collected during the HD(CP)2 Observational Prototype Experiment (HOPE) campaign at Jülich, Germany. The application of the algorithm to different atmospheric scenarios reveals the superior performance of the EKF compared to a nonlinear least squares estimator, particularly in nonidealized conditions.
关键词： microwave radiometry,laser radar,remote sensing,Adaptive Kalman filtering,signal processing
更新于2025-09-19 17:13:59
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[IEEE 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Chicago, IL, USA (2019.6.16-2019.6.21)] 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Effective Prediction of Transmission of Solar Irradiance through Dusty Solar Panels using Atmospheric Aerosol Data for Lahore, Pakistan
摘要： Soil moisture retrievals, delivered as a CATDS (Centre Aval de Traitement des Données SMOS) Level-3 product of the Soil Moisture and Ocean Salinity (SMOS) mission, form an important information source, particularly for updating land surface models. However, the coarse resolution of the SMOS product requires additional treatment if it is to be used in applications at higher resolutions. Furthermore, the remotely sensed soil moisture often does not reflect the climatology of the soil moisture predictions, and the bias between model predictions and observations needs to be removed. In this paper, a statistical framework is presented that allows for the downscaling of the coarse-scale SMOS soil moisture product to a finer resolution. This framework describes the interscale relationship between SMOS observations and model-predicted soil moisture values, in this case, using the variable infiltration capacity (VIC) model, using a copula. Through conditioning, the copula to a SMOS observation, a probability distribution function is obtained that reflects the expected distribution function of VIC soil moisture for the given SMOS observation. This distribution function is then used in a cumulative distribution function matching procedure to obtain an unbiased fine-scale soil moisture map that can be assimilated into VIC. The methodology is applied to SMOS observations over the Upper Mississippi River basin. Although the focus in this paper is on data assimilation applications, the framework developed could also be used for other purposes where downscaling of coarse-scale observations is required.
关键词： microwave radiometry,soil moisture,Hydrology
更新于2025-09-19 17:13:59
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A Hexagonal Pseudo-polar FFT for Formation-Flying Interferometric Radiometry
摘要： A novel mission concept applying satellite formation flight to passive microwave interferometry was recently proposed to significantly improve the interferometer’s spatial resolution. This concept was shown to sample the visibility in a hexagonal tile of polar grids, and to recover the brightness map, this visibility must be inverted via a discrete polar inverse Fourier transform. For a fast and accurate solution, this letter develops a modified hexagonal variant of the pseudo-polar fast Fourier transform (PPFFT) and its inverse and explores its performance when applied to the proposed formation-flight radiometer. Compared to the conventional rectangular PPFFT, we find approximately a fivefold improvement in the recovered radiometric accuracy, where the rms radiometric error is in the order of 10?2 K. The impact of visibility interpolation method is also explored, showing that an FFT-based interpolation technique leads to the most accurate final image recovery.
关键词： mission concept,synthetic aperture imaging,microwave radiometry,Image reconstruction,satellite formation flight
更新于2025-09-11 14:15:04
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[IEEE IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium - Valencia, Spain (2018.7.22-2018.7.27)] IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium - Geophysical Relationship between Cygnss GNSS-R Bistatic Reflectivity and Smap Microwave Radiometry Brightness Temperature Over Land Surfaces
摘要： This work presents an assessment on the correlation between CyGNSS-derived Global Navigation Satellite Systems Reflectometry (GNSS-R) bistatic reflectivity rl? and SMAP-derived brightness temperature BT, over land surfaces. This parametric-study is performed as a function of Soil Moisture Content (SMC), and vegetation opacity τ. Several target areas are selected to evaluate potential differentiated geophysical effects on “active” (as many transmitters as navigation satellites are in view), and passive approaches. Although microwave radiometry has potentially a better sensitivity to SMC, the spatial resolution is poor ~ 40 km. On the other hand, GNSS-R bistatic coherent radar footprint is limited by half of the first Fresnel zone which provides about ~ 150 m of spatial resolution (depending on the geometry). The synergetic combination of both techniques could provide advantages with respect to active monostatic Synthetic Aperture Radar (SAR).
关键词： vegetation opacity,CyGNSS,GNSS-R,land,microwave radiometry,SMAP,multi-static radar,Soil Moisture Content (SMC)
更新于2025-09-10 09:29:36
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Analysis of the Effect of Soil Roughness in the Forward-Scattering Interference Pattern Using Second-Order Small Perturbation Method Simulations
摘要： Soil moisture (SM) is a key geophysical variable that can be estimated at regional scales using remote sensing techniques, by making use of the known relationship between soil re?ectivity and the dielectric constant in the microwave regime. In this context, the exploitation of available illuminators of opportunity that currently emit large amounts of power at microwave frequencies (compared to typical synthetic aperture radar systems) is promising. Some published techniques estimate SM by analyzing the interference pattern (IP) between direct and re?ected signal as measured by a single antenna (i.e., IP technique). In this letter, a new approach to simulate the IP is proposed, in which the soil roughness is modeled straightforwardly using the second-order small perturbation model. Results illustrate that the “notch” in the VV-polarization IP (related to the Brewster angle) can only be directly observed for very low values of soil rms roughness (s < 0.5 cm). For typical values of soil roughness (s ～ 1.2 cm), the notch disappears and only a minimum in the IP is observed near the Brewster angle.
关键词： Electromagnetic and remote sensing,microwave radiometry,Global Navigation Satellite System data,surface and subsurface properties
更新于2025-09-09 09:28:46
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[Institution of Engineering and Technology 12th European Conference on Antennas and Propagation (EuCAP 2018) - London, UK (9-13 April 2018)] 12th European Conference on Antennas and Propagation (EuCAP 2018) - Predicting Mean Radiative Temperature at Millimeter Wavelengths in Continental Climate Areas
摘要： The aim of this work is to present a parametric model for the prediction of the down-welling mean radiative temperature (Tmr) in the microwave region. For the model set-up, the Sky Noise Eddington Model has been exploited to generate a synthetic clouds dataset driven by radiosounding observations. The core of the model, developed in continental climate areas, is the normalization of Tmr for the surface temperature (TS) of the geographic area of interest that makes the Tmr/TS model applicable in each site belonging to the considered climatic area. Retrieval of the predicted Tmr can be done by multiplying the Tmr/TS obtained from the parametric model at the considered attenuation value for the average TS. The model parameters depend on frequency and elevation angle within the range from 23.8 GHz to 49.5 GHz and from 90° to 5°, respectively. A preliminary verification of the model is accomplished, at 23.8 GHz and 31.4 GHz, exploiting Sun-tracking radiometric measurements available in Rome (NY, USA) with promising results: RMSE never exceeds 0.02 and 0.1 at 23.8 GHz and 31.4 GHz, respectively.
关键词： Mean radiative temperature,microwave radiometry,Atmospheric radio-propagation
更新于2025-09-04 15:30:14
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[IEEE IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium - Valencia (2018.7.22-2018.7.27)] IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium - Effect of a Thin DRY Snow Layer on the Lake ICE Thickness Measurement using Wideband Autocorrelation Radiometry
摘要： Wideband autocorrelation radiometry (WiBAR) is a new method to remotely sense the microwave propagation time τdelay of multi-path microwave emission of low loss layered surfaces such as dry snowpack and freshwater lake ice pack. The microwave propagation time τdelay through the pack yields a measure of its vertical extent; thus, this technique is a direct measurement of depth. However, the presence of a different low loss layer on the lake ice pack such as dry snow pack introduces another multi-path interference, which can effect the lake ice pack thickness measurement. We present a simple geophysical forward model for the multipath interference phenomenon and derive the WiBAR system requirements needed to correctly measure the ice pack thickness. An X-band instrument fabricated from commercial-off-the-shelf (COTS) components are used to measure the thickness freshwater lake ice at the University of Michigan Biological Station. Ice thickness retrieval is demonstrated from nadir to 73.9?.
关键词： Snowpack,autocorrelation,icepack,microwave radiometry,remote sensing
更新于2025-09-04 15:30:14
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[IEEE IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium - Valencia (2018.7.22-2018.7.27)] IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium - Precipitation Retrieval Accuracies of the Tropics Constellation of Passive Microwave Cubesats
摘要： This paper evaluates the performance of the passive microwave spectrometer to be launched aboard the Time-Resolved Observations of Precipitation structure and storm Intensity with a Constellation of Smallsats (TROPICS) for retrieving surface precipitation and hydrometeor water paths. The retrieval algorithms employ neural networks trained and evaluated using the physical reference model NCEP/WRF/TBSCAT/F(λ). Results show that TROPICS retrieved surface precipitation rates and hydrometeor water paths agree well with WRF truth. The accuracies of TROPICS retrieved daily, weekly, and monthly surface precipitation amounts are close to those of the Advanced Microwave Sounding Unit (AMSU). The TROPICS constellation will provide useful precipitation retrievals at unprecedented 30-minute temporal resolution.
关键词： CubeSat,microwave radiometry,TROPICS,AMSU,precipitation retrieval
更新于2025-09-04 15:30:14