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Performance assessment and improvement of recursive digital baseflow filters for catchments with different physical characteristics and hydrological inputs

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ENVIRONMENTAL MODELLING & SOFTWARE 2014年 54卷 39-52页

作者： Li, Li Maier, Holger R. Partington, Daniel Lambert, Martin F. Simmons, Craig T. Univ Adelaide Sch Civil Environm & Min Engn Adelaide SA 5005 Australia Flinders Univ S Australia Natl Ctr Groundwater Res & Training Adelaide SA 5001 Australia Flinders Univ S Australia Sch Environm Adelaide SA 5001 Australia

recursive digital filters (RDFs) are one of the most commonly used methods of baseflow separation. However, how accurately they estimate baseflow and how to select appropriate values of filter parameters is generally unknown. In this paper, the output of fully integrated surface water/groundwater (SW/GW) models is used to obtain optimal parameters for, and assess the accuracy of, three commonly used RDFs under a range of physical catchment characteristics and hydrological inputs. The results indicate that the Lyne and Hollick (LH) filter performs better than the Boughton and Eckhardt filters, over a larger range of conditions. In addition, the optimal values of the filter parameters vary considerably for all three filters, depending on catchment characteristics and hydrological inputs. The dataset of the 66 catchment characteristics and hydrological inputs, as well as the corresponding simulated total streamflow and baseflow hydrographs obtained using the SW/GW model, can be downloaded as Supplementary material. (c) 2013 Elsevier Ltd. All rights reserved.

关键词： Baseflow recursive digital filters Framework Prediction Regression models

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Comparison of Baseflow Separation Methods in the German Low Mountain Range

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WATER 2020年第6期12卷 1740页

作者： Kissel, Michael Schmalz, Britta Tech Univ Darmstadt Chair Engn Hydrol & Water Management D-64287 Darmstadt Germany

The last several years in southern Germany brought below average precipitation and high temperatures, leading to considerable challenges in water resource management. Deriving a plausible baseflow estimate is important as it affects aspects of integrated water resource management such as water usage and low flow predictions. The aim of this study is to estimate baseflow in a representative catchment in the German low mountain range and identify suitable baseflow estimation methods for this region. Several different baseflow separation methods, including digital filters, a mass balance filter (MBF) and non-continuous estimation methods were applied and compared to estimate baseflow. Using electric conductivity (EC) for the MBF, June to September and November to May were found to be suitable to estimate the EC of the baseflow and runoff component, respectively. Both weekly and continuous EC monitoring can derive similar EC value component estimates. However, EC estimation of the runoff component requires more careful consideration. The baseflow index (BFI) is estimated to be in the range of 0.4 to 0.5. The Chapman and Maxwell filter, Kille method and the Q90/Q50 ratio are recommended for baseflow estimation in the German low mountain range as they give similar results to the MBF. The Eckhardt filter requires further calibration before application.

关键词： German low mountain range baseflow separation mass balance filtering recession analysis recursive digital filters

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Parameter sensitivity of automated baseflow separation for snowmelt-dominated watersheds and new filtering procedure for determining end of snowmelt period

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HYDROLOGICAL PROCESSES 2019年第5期33卷 876-888页

作者： Voutchkova, Denitza D. Miller, Scott N. Gerow, Kenneth G. Univ Wyoming Dept Ecosyst Sci & Management Laramie WY 82071 USA Univ Wyoming Wyoming Ctr Environm Hydrol & Geophys WyCEHG Laramie WY 82071 USA Univ Wyoming Dept Stat Laramie WY 82071 USA

Automation in baseflow separation procedures allowed fast and convenient baseflow and baseflow index (BF and BFI) estimation for studies including multiple watersheds and covering large spatio-temporal scales. While most of the existing algorithms are developed and tested extensively for rainfall- and baseflow-dominated systems, little attention is paid on their suitability for snowmelt-dominated systems. Current publishing practice in regional-scale studies is to omit BF and BFI uncertainty evaluation or sensitivity analysis. Instead, "standard" and "previously recommended" parameterizations are transferred from rainfall/BF to snowmelt-dominated systems. We believe that this practice should be abandoned. First, we demonstrate explicitly that the three most popular heuristic automated BF separation methods-Lyne-Hollick and Eckhardt recursive digital filters, and the U.K. Institute of Hydrology smoothed minima method-produce a wide range of annual BF and BFI estimates due to parameter sensitivity during the annual snowmelt period. Then, we propose a solution for cases when BF and BFI calibration is not possible, namely excluding the snowmelt-dominated period from the analysis. We developed an automated filtering procedure, which divides the hydrograph into pre-snowbelt, post-snowmelt, and snowmelt periods. The filter was tested successfully on 218 continuous water years of daily streamflow data for four snowmelt-dominated headwater watersheds located in Wyoming (60-837 km(2)). The post-snowmelt BF and BFI metric can be used for characterizing summer low-flows for snowmelt-dominated systems. Our results show that post-snowmelt BF and BFI sensitivity to filter parameterization is reduced compared with the sensitivity of annual BF and BFI and is similar to the sensitivity levels for rainfall/baseflow systems.

关键词： baseflow baseflow index hydrograph separation post-snowmelt baseflow recursive digital filters snowmelt-dominated watersheds

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Tuning CCVT Frequency Response Data for Improvement of Numerical Distance Protection

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IEEE TRANSACTIONS ON POWER DELIVERY 2018年第3期33卷 1062-1070页

作者： Machado, Eubis P. Fernandes, Damasio, Jr. Neves, Washington Luiz A. Fed Univ Vale Sao Francisco Collegiate Elect Engn BR-48902300 Juazeiro BA Brazil Univ Fed Campina Grande Dept Elect Engn BR-58429140 Campina Grande PB Brazil

A new method to numerically estimate the primary voltage waveform of coupling capacitor voltage transformers is presented. The outcome is a simple digital filter suitable for the frequency range from 10 to 60 Hz, enabling us to recover the transformer primary voltage waveform from its secondary voltage waveform. Unlike the techniques reported in the literature, the method does not depend directly on the transformer topology nor on the operational characteristics of the protected system, once only the coupling capacitor voltage transformer frequency response is required as input. The evaluation of the technique is performed through digital simulations using the Alternative Transients Program and transmission-line data from the Brazilian National Power System Grid. Frequency- and time-domain analysis of two coupling capacitor voltage transformers with different topologies and voltage levels are presented. It is shown that the proposed method is effective for the dynamic correction of low-frequency disturbances that may improve the speed, reliability, and security of the numerical distance relay.

关键词： Instrument transformers frequency response recursive digital filters power system protection

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Design Methodology for Nearly Linear-Phase recursive digital filters by Constrained Optimization

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IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS I-REGULAR PAPERS 2010年第7期57卷 1719-1731页

作者： Guindon, David Shpak, Dale J. Antoniou, Andreas Univ Victoria Dept Elect & Comp Engn Victoria BC V8W 3P6 Canada

A methodology for the design of recursive digital filters having nearly linear phase response is proposed. The underlying design method is of the direct type whereby the filter is designed as a single unit. The design problem is formulated as a cascade of filter sections where each section is represented by a biquadratic transfer function either in the conventional polynomial form or in the polar form. The design problem is then solved using a constrained Newton's method whereby constraints are used to assure the stability of the filter, to control the step size in order to achieve fast convergence, and to eliminate a real-axis pole-migration problem that often interferes with the design process. Several design examples demonstrate that when compared with filters designed using existing state-of-the-art methods, the proposed methodology yields filters having reduced order and/or improved performance.

关键词： recursive digital filters infinite-impulse response (IIR) digital filters nearly linear-phase filters constant-delay filters

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Efficient Sampling of Band-Limited Signals From Sine Wave Crossings

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IEEE TRANSACTIONS ON SIGNAL PROCESSING 2012年第1期60卷 503-508页

作者： Selva, J. Univ Alicante Dept Phys Syst Engn & Signal Theory DFISTS E-03080 Alicante Spain

This correspondence presents an efficient method for reconstructing a band-limited signal in the discrete domain from its crossings with a sine wave. The method makes it possible to design analog-to-discrete (A/D) converters that only deliver the crossing timings, which are then used to interpolate the input signal at arbitrary instants. Potentially, it may allow for reductions in power consumption and complexity in these converters. The reconstruction in the discrete domain is based on a recently-proposed modification of the Lagrange interpolator, which is readily implementable with linear complexity and efficiently, given that it reuses known schemes for variable fractional-delay (VFD) filters. As a spin-off, the method allows one to perform spectral analysis from sine wave crossings with the complexity of the FFT. Finally, the results in the correspondence are validated in several numerical examples.

关键词： Interpolation Lagrange interpolation nonuniform sampling recursive digital filters signal sampling spectral analysis

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Design of Barycentric Interpolators for Uniform and Nonuniform Sampling Grids

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IEEE TRANSACTIONS ON SIGNAL PROCESSING 2010年第3期58卷 1618-1627页

作者： Selva, J. Univ Alicante Dept Phys Syst Engn & Signal Theory DFISTS E-03080 Alicante Spain

This paper proposes a method to convert a fixed instant interpolator for band-limited signals into a variable instant one, which has the form of a barycentric interpolator. This interpolator makes it possible to approximate the signal and its derivatives with minimal complexity in a range that surrounds the initial instant, and is applicable to uniform and nonuniform sampling grids. The barycentric form of the interpolator is derived using two different procedures, first by the repeated use of Bernstein's inequality and Taylor's theorem, and second by truncating a Lagrange-type series. These procedures show that the proposed method can be applied to existing fixed instant interpolators, and that it can be accurate in long time intervals. Finally, an evaluation procedure for barycentric interpolators and their derivatives is presented that minimizes the number of divisions, solving at the same time the numerical problems associated with small denominators. This paper includes several numerical examples.

关键词： Barycentric interpolation interpolation Lagrange interpolation nonuniform sampling recursive digital filters sampling

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Design of recursive digital filters in view of their robustness

Design of recursive digital filters in view of their robustn...

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International Conference on Mixed Design of Integrated Circuits and Systems

作者： Borys, A. University of Technology and Agriculture Poland Institute of Telecommunications Faculty of Telecommunications and Electrical Engineering University of Technology and Agriculture (ATR) 85-796 Bydgoszcz ul. Prof. S. Kaliskiego 7 Poland

ISBN: (纸本)8392263219

In this paper, some issues of the design of recursive digital filters in view of their robustness are discussed. After giving some general remarks regarding the mechanisms of arising nonlinear distortion in filters, and regarding the robustness property, two problems are considered in detail. That is the forced-response stability and occurrence of harmonic distortion are investigated. It is shown here that the forced-response stability is equivalent to the attractivity property of the (realized) filter. Furthermore, the harmonic distortion due to the finite wordlength in a class of digital filters of which poles lie near the point z = 1 is analysed, too. It is shown that by applying the method of harmonics balance it is possible to obtain the closed-form results for the higher harmonics and for the change in the filter transfer function. The expressions obtained describe, however, only qualitatively the phenomenon discussed;they do not provide quantitative results.

关键词： recursive digital filters nonlinear effects in filters filter robustness

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Functionally Weighted Lagrange Interpolation of Band-Limited Signals From Nonuniform Samples

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IEEE TRANSACTIONS ON SIGNAL PROCESSING 2009年第1期57卷 168-181页

作者： Selva, J. Univ Alicante Dept Phys Syst Engn & Signal Theory DFISTS E-03080 Alicante Spain

A modification of the conventional Lagrange interpolator is proposed in this paper, that allows one to approximate a band-limited signal from its own nonuniform samples with high accuracy. The modification consists in applying the Lagrange method to the signal, but premultiplied by a fixed function, and then solving for the desired signal value. Its efficiency lies in the fact that the fixed function is independent of the sampling instants. It is shown in this paper that the function can be selected so that the interpolation error decreases exponentially with the number of samples, for the case in which the sampling instants have a maximum deviation from a uniform grid. This paper includes a low-complexity recursive implementation of the method. Its accuracy is validated in the numerical examples by comparison with several interpolators in the literature, and by deriving upper and lower bounds for its maximum error.

关键词： Interpolation Lagrange interpolation nonuniform sampling recursive digital filters sampling

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A Multipath-resistant Precise Tracking Method for BOC Signal

A Multipath-resistant Precise Tracking Method for BOC Signal

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2009 3rd IEEE International Symposium on Microwave,Antenna,Propagation and EMC Technologies for Wireless Communications

作者： Yao Yanxin Yang Dongkai DingFan School of Electronics and Information Engineering Beihang University Beijing China

We propose a new recursive least square （RLS） based method for precisely tracking carrier and code navigation signals of BOC（m,n）,Alt- BOC（m,n） any other systems in multipath environment. The method can estimate multipath profile at high resolution by self- adaptively filtering local correlation function according to correlation value after demodulation and spectrum dispreading, and the filter coefficient when filter converges can estimate direct path tracking error and multipath profile. We also propose the complete structure of the method. Simulation verifies that the method can fulfill precise tracking of code and carrier and estimates tracking error and multipath profile at 0.025 chip for time resolution and 0.003 cycle for phase resolution in the condition of both 40.092MHz sampling rate and high SNR E1 BOC （1,1） signal.

关键词： Global Navigation Satellite System （GNSS） Binary Offset Carrier （BOC） recursive digital filters multipath channels tracking

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