scholarly journals MORPHOLOGICAL MODELING OF BAR DYNAMICS WITH DELFT3D: THE QUEST FOR OPTIMAL FREE PARAMETER SETTINGS USING AN AUTOMATIC CALIBRATION TECHNIQUE

2011 ◽  
Vol 1 (32) ◽  
pp. 60 ◽  
Author(s):  
Christophe Briere ◽  
Alessio Giardino ◽  
Jebbe Van der Werf
Keyword(s):  
Calibration Method ◽  
Calibration Procedure ◽  
Sand Transport ◽  
Automatic Calibration ◽  
Physical Processes ◽  
Calibration Technique ◽  
Validation Test ◽  
Morphological Modeling ◽  
Morphodynamic Evolution ◽  
Calibration Parameters

The modeling of bar dynamics is crucial for understanding coastal dynamics and shoreface nourishment evolution. Due to the complexity and variability of the physical processes involved, the formulations developed within the process-based numerical modelling system Delft3D for representing the forcing of the morphodynamic processes (waves, currents, sand transport) contain a high number of calibration parameters. Therefore, the setting up of any Delft3D computation requires a tedious calibration work, usually carried out manually and therefore by definition subjective. The aim of this work is the setting up of an automated and objective calibration procedure for Delft3D morphodynamic computations. A number of calibration parameters have been identified based on a careful sensitivity analysis. The calibration method named DUD (Does not Use Derivatives) is selected and coupled to a alongshore uniform Delft3D model. The validity of the implementation is shown based on synthetic tests (twin experiments). The validation test is carried out using field data collected at Egmond-aan-Zee (The Netherlands). This paper shows that the tool can be successfully used to calibrate Delft3D. However, further research is especially required to understand whether the computed parameters settings only simulate the best morphodynamic evolution of the bars or also describe properly the underlying physical processes.

scholarly journals Effectiveness of Automatic and Manual Calibration of an Office Building Energy Model

2019 ◽  
Vol 9 (10) ◽  
pp. 1985 ◽  
Author(s):  
Cristina Cornaro ◽  
Francesco Bosco ◽  
Marco Lauria ◽  
Valerio Adoo Puggioni ◽  
Livio De Santoli
Keyword(s):  
Dynamic Simulation ◽  
Simulated Data ◽  
Simulation Models ◽  
Calibration Method ◽  
Calibration Procedure ◽  
Office Building ◽  
Automatic Calibration ◽  
Advantages And Disadvantages ◽  
Dynamic Simulation Model ◽  
The Difference

Energy reduction can benefit from the improvement of energy efficiency in buildings. For this purpose, simulation models can be used both as diagnostic and prognostic tools, reproducing the behaviour of the real building as accurately as possible. High modelling accuracy can be achieved only through calibration. Two approaches can be adopted—manual or automatic. Manual calibration consists of an iterative trial and error procedure that requires high skill and expertise of the modeler. Automatic calibration relies on mathematical and statistical methods that mostly use optimization algorithms to minimize the difference between measured and simulated data. This paper aims to compare a manual calibration procedure with an automatic calibration method developed by the authors, coupling dynamic simulation, sensitivity analysis and automatic optimization using IDA ICE, Matlab and GenOpt respectively. Differences, advantages and disadvantages are evidenced applying both methods to a dynamic simulation model of a real office building in Rome, Italy. Although both methods require high expertise from operators and showed good results in terms of accuracy, automatic calibration presents better performance and consistently helps with speeding up the procedure.

scholarly journals A Spliced Satellite Optical Camera Geometric Calibration Method Based on Inter-Chip Geometry Constraints

2021 ◽  
Vol 13 (14) ◽  
pp. 2832
Author(s):  
Tao Wang ◽  
Yan Zhang ◽  
Yongsheng Zhang ◽  
Zhenchao Zhang ◽  
Xiongwu Xiao ◽  
...  
Keyword(s):  
Satellite Images ◽  
Calibration Method ◽  
Calibration Procedure ◽  
Calibration Model ◽  
Geometric Calibration ◽  
Sensing Technology ◽  
Calibration Models ◽  
Major Bottleneck ◽  
Chip Geometry ◽  
Calibration Parameters

When in orbit, spliced satellite optical cameras are affected by various factors that degrade the actual image stitching precision and the accuracy of their data products. This is a major bottleneck in the current remote sensing technology. Previous geometric calibration research has mostly focused on stitched satellite images and has largely ignored the inter-chip relationship among original multi-chip images, resulting in accuracy loss in geometric calibration and subsequent image products. Therefore, in this paper, a novel geometric calibration method is proposed for spliced satellite optical cameras. The integral geometric calibration model was developed on inter-chip geometry constraints among multi-chip images, including the corresponding external and internal calibration models. The proposed approach improves uncontrolled geopositioning accuracy and enhances mosaic precision at the same time. For evaluation, images from the optical butting satellite ZiYuan-3 (ZY-3) and mechanical interleaving satellite Tianhui-1 (TH-1) were used for the experiments. Multiple sets of satellite data of the Songshan Calibration field and other regions were used to evaluate the reliability, stability, and applicability of the calibration parameters. The experiment results found that the proposed method obtains reliable camera alignment angles and interior calibration parameters and generates high-precision seamless mosaic images. The calibration scheme is not only suitable for mechanical interleaving cameras with large geometric displacement among multi-chip images but is also effective for optical butting cameras with minor chip offset. It also significantly improves uncontrolled geopositioning accuracy for both types of spliced satellite images. Moreover, the proposed calibration procedure results in multi-chip satellite images being seamlessly stitched together and mosaic errors within one pixel.

An Automatic Calibration Method in the Crop Architecture 3D Scanner

2011 ◽  
Vol 204-210 ◽  
pp. 493-497
Author(s):  
Sheng Yong Xu ◽  
De Hua Li ◽  
Zhu Li ◽  
Qing Wei
Keyword(s):  
Three Dimensional ◽  
Calibration Method ◽  
Reference Points ◽  
Scanning System ◽  
Automatic Calibration ◽  
Automatic Method ◽  
Essential Work ◽  
3D Scanner ◽  
Average Value ◽  
Calibration Parameters

Calibration is an essential work in three-dimensional scanning system. The operation of existing calibration is complex and tedious. In this paper, we design a DLT-based automatic method of calibration, in which the calibration reference points are detected automatically. Then we can figure out a series of calibration parameters from these points. The average value of all parameters is just the calibration parameters. The experimental results show that the method we proposed is not only guaranteeing the calibration precision but also simplifying the calibration operation comparing with the traditional manual calibration method.

scholarly journals Non-destructive Dielectric Measurements and Calibration for Thin Materials Using Waveguide-Coaxial Adaptors

2014 ◽  
Vol 14 (1) ◽  
pp. 16-24 ◽  
Author(s):  
K. Y. You ◽  
Z. Abbas ◽  
M. F. A. Malek ◽  
E. M. Cheng
Keyword(s):  
Calibration Method ◽  
Calibration Procedure ◽  
Reflection Coefficients ◽  
Dielectric Measurements ◽  
Finite Samples ◽  
Open Standard ◽  
Rectangular Waveguides ◽  
Standard Values ◽  
Calibration Techniques ◽  
Non Destructive

Abstract This paper focuses on the calibration of apertures for rectangular waveguides using open-short-load (OSL) standards and transmission-line (TL) approaches. The reflection coefficients that were measured using both calibration techniques were compared with the coefficients acquired using the thru-reflect-line (TRL) method. In this study, analogous relationships between the results of OSL calibration and TL calibration were identified. In the OSL calibration method, the theoretical, open-standard values are calculated from quasi-static integral models. The proposed TL calibration procedure is a simple, rapid, broadband approach, and its results were validated by using the OSL calibration method and by comparing the results with the calculated integral admittance. The quasi-static integral models were used to convert the measured reflection coefficients to relative permittivities for the infinite samples and the thin, finite samples

scholarly journals Consistent Calibration of VIRR Reflective Solar Channels Onboard FY-3A, FY-3B, and FY-3C Using a Multisite Calibration Method

2018 ◽  
Vol 10 (9) ◽  
pp. 1336 ◽  
Author(s):  
Ling Wang ◽  
Xiuqing Hu ◽  
Lin Chen ◽  
Lingli He
Keyword(s):  
Radiative Transfer ◽  
Calibration Method ◽  
Daily Basis ◽  
Current Approach ◽  
Automatic Calibration ◽  
Vicarious Calibration ◽  
Radiative Transfer Modeling ◽  
Reflectance Data ◽  
Calibration Coefficients

The FengYun-3 (FY-3) Visible Infrared Radiometer (VIRR), along with its predecessor, the Multispectral Visible Infrared Scanning Radiometer (MVISR), onboard the FY-1C and FY-1D, has collected continuous daily global observations for 18 years. Achieving accurate and consistent calibration for VIRR reflective solar bands (RSBs) has been challenging, as there is no onboard calibrator and the frequency of in situ vicarious calibration is limited. In this study, a new set of reflectance calibration coefficients were derived for RSBs of the FY-3A, FY-3B, and FY-3C VIRRs using a multisite (MST) calibration method. This method is an extension of a previous MST calibration method, which relies on radiative transfer modeling over the multiple stable earth sites, and no synchronous in situ measurements are needed; hence, it can be used to update the VIRR calibration on a daily basis. The on-orbit radiometric changes of the VIRR onboard the FY-3 series were assessed based on analyses of new sets of calibration slopes. Then, all recalibrated VIRR reflectance data over Libya 4, the most frequently used stable Earth site, were compared with those provided from the Level 1B (L1B) product. Additional validation was performed by comparing the recalibrated VIRR data with those derived from radiative transfer simulations using measurements from automatic calibration instruments in Dunhuang. The results indicate that the radiometric response changes of the VIRRs onboard FY-3A and FY-3B were larger than those of FY-3C VIRR and were wavelength dependent. The current approach can provide consistent VIRR reflectances across different FY-3 satellite platforms. After recalibration, differences in top-of-atmosphere (TOA) reflectance data across different VIRRs during the whole lifetime decreased from 5–10% to less than 3%. The comparison with the automatic calibration method indicates that MST calibration shows good accuracy and lower temporal oscillations.

THE CALIBRATION OF AN ARRAY OF ACCELEROMETERS

2011 ◽  
Vol 35 (2) ◽  
pp. 251-267 ◽  
Author(s):  
Dany Dubé ◽  
Philippe Cardou
Keyword(s):  
Angular Velocity ◽  
Rigid Body ◽  
Least Squares ◽  
Calibration Method ◽  
Calibration Procedure ◽  
Rigid Bodies ◽  
New Method ◽  
Scale Factors ◽  
Array Calibration ◽  
The One

An accelerometer-array calibration method is proposed in this paper by which we estimate not only the accelerometer offsets and scale factors, but also their sensitive directions and positions on a rigid body. These latter parameters are computed from the classical equations that describe the kinematics of rigid bodies, and by measuring the accelerometer-array displacements using a magnetic sensor. Unlike calibration schemes that were reported before, the one proposed here guarantees that the estimated accelerometer-array parameters are globally optimum in the least-squares sense. The calibration procedure is tested on OCTA, a rigid body equipped with six biaxial accelerometers. It is demonstrated that the new method significantly reduces the errors when computing the angular velocity of a rigid body from the accelerometer measurements.

The Design of HTG Automatic Calibration System Based on Fuzzy Theory

2012 ◽  
Vol 468-471 ◽  
pp. 1490-1494
Author(s):  
Qi Ren ◽  
Tian Fei Ren
Keyword(s):  
Control Theory ◽  
System Design ◽  
Fuzzy Theory ◽  
Calibration Method ◽  
Automatic Calibration ◽  
Matlab Simulation ◽  
Calibration System ◽  
Oil Tank ◽  
Fuel Level

ABSTRACT：It introduces a kind of an Automatic Calibration System, especially for long-term drift of oil tank gauging system. long-term drift serious influence on measuring the accuracy and reliability of the system. With theory of Hydrostatic Tank Gauging[1]（HTG），as soon as the long-term drift occurring, the detection drift of oil pressure valueΔp will drift，and soon other the parameters of tank Gauging will be occurred. Because the value of Δp is difficult to directly determine, This paper puts forward a kind of automatic calibration method to obtain Δp according to the fuel level drift Δh) indirectly,By means of the HTG double level switches and fuzzy control theory. At last, by MATLAB simulation verify the correctness of the system design.

Sign in / Sign up

Export Citation Format

Share Document