?url_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Adc&rft.relation=http%3A%2F%2Fd-scholarship-dev.library.pitt.edu%2F11743%2F&rft.title=Discrimination+of+Bedform+Scales+Using+Robust+Spline+Filters+and+Wavelet+Transforms%3A+Methods+and+Application+to+Synthetic+Signals+and+the+Rio+Parana%2C+Argentina&rft.creator=Gutierrez%2C+Ronald+R.&rft.description=Currently%2C+there+is+no+standard+nomenclature+and+procedure+to+systematically+identify+the+scale+and+magnitude+of+bedforms+such+as+bars%2C+dunes+and+ripples+that+are+commonly+present+in+many+sedimentary+environments.+This+thesis+proposes+a+standardization+of+the+nomenclature+and+symbolic+representation+of+bedforms%2C+and+details+the+combined+application+of+robust+spline+filters+and+continuous+wavelet+transforms+to+discriminate+these+morphodynamic+features%2C+namely+bedform+hierarchies+(BHs).+The+proposed+methodology+for+bedform+discrimination+is+applied+to+synthetic+bedform+signals%2C+which+are+sampled+at+a+Nyquist+ratio+interval+of+5+to+100+and+a+signal-to-noise+ratio+interval+of+1+to+20%2C+and+to+a+detailed+3D+bed+survey+of+the+Rio+Parana%2C+Argentina%2C+which+exhibits+large-scale+dune+bedforms+with+superimposed%2C+smaller+bedforms.+After+discriminating+the+synthetic+bedform+signals+into+3+BHs+that+represent+bars%2C+dunes+and+ripples%2C+the+accuracy+of+the+methodology+is+quantified+by+estimating+the+reproducibility%2C+the+cross+correlation+and+the+standard+deviation+ratio+of+the+actual+and+retrieved+signals.+For+the+case+of+the+field+measurements%2C+the+proposed+method+is+used+to+discriminate+small+and+large+dunes%3B+and+subsequently%2C+obtain+and+statistically+analyze+the+common+morphological+descriptors+such+as+wavelength%2C+slope%2C+and+amplitude+for+both+stoss+and+lee+sides+of+these+different+size+bedforms.+The+analysis+of+the+synthetic+signals+demonstrates+that+the+Morlet+wavelet+function+is+the+most+efficient+in+retrieving+smaller+periodicities+such+as+ripples+and+that+the+proposed+methodology+effectively+discriminate+the+waves+of+different+periodicities+scales+for+Nyquist+ratios+higher+than+50+and+signal-to-noise+ratios.+The+analysis+of+the+bedforms+of+the+Parana+River+reveals+that+in+most+cases%2C+a+Gamma+probability+distribution+(with+a+positive+skewness)+best+describes+the+dimensionless+wavelength+and+amplitude+for+both+the+lee+and+stoss+sides+of+large+dunes.+For+the+case+of+the+smaller+superimposed+dunes%2C+the+dimensionless+wavelength+shows+a+discrete+behavior+governed+by+the+sampling+frequency+of+the+data%2C+and+the+dimensionless+amplitude+better+fits+the+Gamma+probability+distribution%2C+again+with+a+positive+skewness.&rft.date=2012-06-04&rft.type=University+of+Pittsburgh+ETD&rft.type=PeerReviewed&rft.format=application%2Fpdf&rft.language=en&rft.identifier=http%3A%2F%2Fd-scholarship-dev.library.pitt.edu%2F11743%2F1%2FETD-RRGutierrez.pdf&rft.identifier=++Gutierrez%2C+Ronald+R.++(2012)+Discrimination+of+Bedform+Scales+Using+Robust+Spline+Filters+and+Wavelet+Transforms%3A+Methods+and+Application+to+Synthetic+Signals+and+the+Rio+Parana%2C+Argentina.++Master's+Thesis%2C+University+of+Pittsburgh.++++(Unpublished)++