- 标题
- 摘要
- 关键词
- 实验方案
- 产品
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Crosstalk effect mitigation in black body warm-up cool-down calibration for Terra MODIS longwave infrared photovoltaic bands
摘要： The crosstalk phenomena in Terra MODerate-resolution Imaging Spectroradiometer (MODIS) midwave-to-longwave infrared (LWIR) photovoltaic (PV) bands (bands 27-30) have recently been individually studied and characterized, and a correction algorithm has been developed. The routine calibration of the four LWIR PV bands uses an onboard black body (BB) based on a quadratic model for the relationship between the at-aperture radiance and the background subtracted instrument response. While the crosstalk correction has been successfully applied in both the routine BB calibration (scan basis) to correct the crosstalk effect in the linear term and the Earth view (EV) radiance in our previous investigations on the bands 27–29, the most recent work on band 30 demonstrated a newfound necessity to include the impact of the crosstalk effect on the nonlinear term as well as the offset. In this paper, we analyze the calibration calculation under a variety of conditions consistent with the MODIS Collection 6 settings to examine the impact of the crosstalk effect in the two terms derived from the BB warm-up-cool-down (WUCD) calibration. We show that with correct account of the crosstalk effect in the WUCD calibration, the sudden changes and other abnormal features that have been observed in the two terms for many years are effectively and remarkably removed. In addition, imagery for bands 27–29 using the calibration result fully corrected for the electronic crosstalk effect shows further improvement over previous results that account for only the corrected linear term, whereas for the band 30 different testing scenes validate the previous fully corrected ?ndings.
关键词： crosstalk effect,LWIR photovoltaic bands,Terra MODIS,black body calibration,WUCD calibration
更新于2025-09-19 17:13:59
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Quantitative analysis of saindha salt using laser induced breakdown spectroscopy and cross-validation with ICP-MS
摘要： Saindha salt is considered to be more advantageous than the other edible salts for the patients suffering from diabetes, blood pressure and kidney diseases. To explore the constituent elements of this salt, laser induced breakdown spectroscopy (LIBS) has been exploited for its qualitative and quantitative analysis. The third harmonic (355 nm) of a Q-switched Nd:YAG laser has been used to produce the saindha salt plasma and the time integrated optical emission spectra were registered using a set of six miniature spectrometers covering the spectral range of 230–805 nm. The spectroscopic analysis of the emission spectra predominately revealed numerous neutral or singly ionized emission lines of Ca, Mg, Na, K, Fe, Sr, Si, Li and Al. The laser produced plasma was characterized by calculating the electron temperature from the Boltzmann plots and the electron number density from the Stark broadened line profile as a function of laser irradiance and distance from the target sample. The relative concentration of the constituent elements was extracted by the integrated line intensities of the strongest spectral line of each element using the self-calibration-LIBS (SC-LIBS) and one-line calibration free-LIBS (OLCF-LIBS) methods. For cross-validation, the LIBS results have been compared with that obtained from the inductively coupled plasma-mass spectroscopy (ICP-MS) showing good agreement.
关键词： inductively coupled plasma-mass spectroscopy,saindha salt,elemental analysis,one-line calibration-free LIBS,self-calibration-LIBS,plasma parameters
更新于2025-09-19 17:13:59
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Online Milk Quality Assessment during Milking Using Near-infrared Spectroscopic Sensing System
摘要： In recent times, there has been an urgent requirement for a technique that can be used by dairy farmers to assess the quality of milk of an individual cow during milking. A near-infrared (NIR) spectroscopic sensing system was designed on an experimental basis for the online assessment of the three major milk constituents (fat, protein, and lactose), solids not fat (SNF), milk urea nitrogen (MUN), and somatic cell count (SCC). This system was used to obtain the NIR spectra of non-homogenized milk during milking over a wavelength range of 700 to 1,050 nm. Calibration models for predicting three major milk constituents, SNF, MUN and SCC of non-homogenized milk were developed, and the precision and accuracy of the models were validated. The coefficients of determination, standard errors of prediction, and bias values showed high levels of precision and accuracy for the prediction of the considered parameters. The results indicated that the developed NIR spectroscopic sensing system can be used to assess milk quality in real-time during milking. This system can provide dairy farmers with information concerning milk quality and physiological condition of each cow, and can therefore optimize dairy farm management.
关键词： calibration models,milk constituents,somatic cell count,solids not fat,milk urea nitrogen
更新于2025-09-19 17:13:59
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[IEEE 2019 IEEE Power & Energy Society General Meeting (PESGM) - Atlanta, GA, USA (2019.8.4-2019.8.8)] 2019 IEEE Power & Energy Society General Meeting (PESGM) - A Probabilistic Data-Driven Method for Photovoltaic Pseudo-Measurement Generation in Distribution Systems
摘要： The Kinect system is arguably the most popular 3-D camera technology currently on the market. Its application domain is vast and has been deployed in scenarios where accurate geometric measurements are needed. Regarding the PrimeSense technology, a limited amount of work has been devoted to calibrating the Kinect, especially the depth data. The Kinect is, however, inevitably prone to distortions, as independently confirmed by numerous users. An effective method for improving the quality of the Kinect system is by modeling the sensor’s systematic errors using bundle adjustment. In this paper, a method for modeling the intrinsic and extrinsic parameters of the infrared and colour cameras, and more importantly the distortions in the depth image, is presented. Through an integrated marker- and feature-based self-calibration, two Kinects were calibrated. A novel approach for modeling the depth systematic errors as a function of lens distortion and relative orientation parameters is shown to be effective. The results show improvements in geometric accuracy up to 53% compared with uncalibrated point clouds captured using the popular software RGBDemo. Systematic depth discontinuities were also reduced and in the check-plane analysis the noise of the Kinect point cloud was reduced by 17%.
关键词： 3D/stereo scene analysis,quality assurance,quantization,camera calibration,Kinect
更新于2025-09-19 17:13:59
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[IEEE OCEANS 2019 MTS/IEEE SEATTLE - Seattle, WA, USA (2019.10.27-2019.10.31)] OCEANS 2019 MTS/IEEE SEATTLE - Polarized Complex Modulation for Underwater Wireless Optical Communications
摘要： We describe a novel iterative methodology for computing a set of low-sidelobe beamforming weights for an airborne, electronically-steered phased-array radar using an in-flight stochastic optimization routine performed over a number of coherent processing intervals (CPIs). The proposed approach is notable in that it does not rely upon a good antenna calibration and only requires digitization of the radar’s sum beam. By observing the radar ground clutter, the algorithm iteratively adjusts the beamformer. Furthermore, it is computationally inexpensive and scales favorably to radars comprising very large numbers of antenna elements and requiring extremely low sidelobes.
关键词： radar,clutter,iterative,Calibration,stochastic optimization,phased arrays
更新于2025-09-19 17:13:59
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Emerging micropollutants determination by NIR spectroscopy using pseudo-univariate calibration and TF-SPME coupled with 96-well plate system
摘要： In this study, an innovative approach was developed to determine simultaneously the emerging micropollutants bisphenol A (BPA), 3-(4-methylbenzylidene) camphor (4-MBC), triclocarban (TCC), benzophenone (BZP) and 2-ethyl-hexyl-4-trimethoxycinnamate (EHMC) in water employing near infrared spectroscopy (NIR) coupled with thin film solid-phase microextraction (TF-SPME) using the chemometric tool of multivariate curve resolution with alternating least squares (MCR-ALS). In addition, a 96-well plate system was employed to increase the analysis throughput of the proposed methodology. Samples were submitted to TF-SPME procedure (previously optimized in previous work to exhibit the best performance for extraction and desorption conditions) and its extracts were analyzed by NIR. A pseudo-univariate calibration model for each analyte was developed by associating the relative concentration obtained using MCR-ALS with the reference concentration (i.e. theoretical concentration). The correlation coefficients obtained were 0.9238, 0.8722, 0.7872, 0.8856 and 0.9128 for BPA, 4-MBC, TCC, BZP and EHMC, respectively. With the use of these pseudo-univariate models, the determination of the analytes exhibited absolute errors lowers than those of the chromatographic technique for BZP and TCC. For BPA, 4-MBC and EHMC the absolute error was lower than 10 μg L-1. This approach can provide a cheap and rapid strategy for the direct quantification of these micropollutants in water samples.
关键词： pseudo-univariate calibration,MCR-ALS,96-well plate,Emerging micropollutants,TF-SPME,NIR
更新于2025-09-19 17:13:59
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Impact of Postplating Annealing on Defect Activation in Boron-Doped PERC Solar Cells
摘要： The cold calibration count from the Advanced Technology Microwave Sounder (ATMS) space view increases when the lunar radiation intrudes its antenna field of view (FOV). This increase is referred to as lunar contamination since the cold count is not matched with the specified brightness temperature of 2.73 K. For ATMS, it is found that the elapse time of lunar intrusion (LI) and the magnitude of the cold count increase are channel dependent. If the lunar-affected calibration counts are rejected in the processing, a data gap can be shown in brightness temperature at all channels. At ATMS channels 1 and 2, which have a large FOV, the LI can result in an increase of 40 counts in cold calibration. At higher frequency channels which have a smaller FOV size, the LI intensity is much stronger and can be as large as a few hundred counts. The LI becomes significant when its radiation appears in the ATMS antenna main beam. In the current ATMS operational calibration algorithm, the cold count anomaly is detected when the intensity of LI exceeds a certain threshold. The lunar radiation can be also corrected in the ATMS calibration. In doing so, a lunar radiation term is derived as a function of antenna gain, the solid angle of the Moon, and the brightness temperature of the Moon disk. This algorithm is applied in an ATMS calibration system developed at NOAA and shows a successful removal of all the lunar contamination on the earth-scene brightness temperature.
关键词： calibration,Advanced Technology Microwave Sounder (ATMS),contamination,lunar intrusion (LI)
更新于2025-09-19 17:13:59
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[IEEE 2019 IEEE 8th Global Conference on Consumer Electronics (GCCE) - Osaka, Japan (2019.10.15-2019.10.18)] 2019 IEEE 8th Global Conference on Consumer Electronics (GCCE) - Swallowing Measurement for a Healthy Subject Using a Hetero-Core Optical Fiber Sensor
摘要： In this paper, we study the time-of-arrival (TOA) based self-calibration problem of dual-microphone array for known and unknown rack distance, and also for different combinations of dimension for the af?ne spaces spanned by the receivers and by the senders. Particularly, we analyze the minimum cases and present minimum solvers for the case of microphones and speakers in 3-D/3-D, in 2-D/3-D, and in 3-D/2-D, with given or unknown rack length. We identify for each of these minimal problems the number of solutions in general and develop ef?cient and numerically stable, non-iterative solvers. Solving these problems are of both theoretical and practical interest. This includes understanding what the minimal problems are and how and when they can be solved. The solvers can be used to initialize local optimization algorithms for ?nding the maximum likelihood estimate of the parameters. The solvers can also be used for robust estimation of the parameters in the presence of outliers, using, e.g., RANSAC algorithms. We demonstrate that the proposed solvers are numerically stable in synthetic experiments. We also demonstrate how the solvers can be used with the RANSAC paradigm. We also apply our method for several real data experiments, using ultra-wide-band measurements and using acoustic data.
关键词： dual-microphone array,Time-of-arrival (TOA),minimal solver,self-calibration
更新于2025-09-19 17:13:59
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[IEEE 2019 IEEE International Conference on Space Optical Systems and Applications (ICSOS) - Portland, OR, USA (2019.10.14-2019.10.16)] 2019 IEEE International Conference on Space Optical Systems and Applications (ICSOS) - Demonstration of Reliable High-Rate Optical Communication over an Atmospheric Link using ARQ
摘要： A quaternion-based attitude unscented Kalman ?lter is formulated with quaternion errors parameterized by small angle approximations and is applied to a ?lter with a state vector consisting of the attitude quaternion and the gyro bias vector. The ?lter is evaluated using extensive Monte Carlo data in a simulated lost-in-space scenario of a low-Earth orbiting spacecraft processing only three-axis magnetometer and gyro measurements. The ?lter is found to be robust, accurate, and rapidly convergent in this scenario for small true gyro biases and small initial uncertainties in their values, often converging in only one half of an orbit period to an attitude accuracy of 0.1 degrees. The ?lter convergence is found to depend signi?cantly on the value of the true gyro biases as well as the initial gyro bias covariances. Monte Carlo results also indicate that this unscented Kalman ?lter is signi?cantly less robust than an extended Kalman ?lter with the same attitude approach, but performs slightly better than another unscented Kalman ?lter with a generalized Rodrigues parameter approach to quaternion errors.
关键词： Attitude control,Kalman ?lters,gyroscopes,calibration,unscented,spacecraft,geomagnetism
更新于2025-09-19 17:13:59
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[IEEE 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Munich, Germany (2019.6.23-2019.6.27)] 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Phase Sensitive Amplification in a Periodically Poled Silica Fiber
摘要： This paper describes the design, development and testing of an AR system that was developed for aerospace and ground vehicles to meet stringent accuracy and robustness requirements. The system uses an optical see-through HMD, and thus requires extremely low latency, high tracking accuracy and precision alignment and calibration of all subsystems in order to avoid mis-registration and “swim”. The paper focuses on the optical/inertial hybrid tracking system and describes novel solutions to the challenges with the optics, algorithms, synchronization, and alignment with the vehicle and HMD systems. Tracker accuracy is presented with simulation results to predict the registration accuracy. A car test is used to create a through-the-eyepiece video demonstrating well-registered augmentations of the road and nearby structures while driving. Finally, a detailed covariance analysis of AR registration error is derived.
关键词： Inertial,hybrid tracking,see through HMD,sensor fusion,calibration,registration,augmented reality,image processing
更新于2025-09-19 17:13:59