Memorial University DAI: A comparison of two inversion methods for determination of sand concentration and size from multifrequency acoustic backscatter

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Title	A comparison of two inversion methods for determination of sand concentration and size from multifrequency acoustic backscatter
Author	Crawford, Anna M., 1966-
Description	Thesis (M.Sc.)-- Memorial University of Newfoundland, 1992. Physics
Date	1992
Pagination	114 leaves : ill.
Subject	Suspended sediments--Measurement
Degree	M.Sc.
Degree Grantor	Memorial University of Newfoundland. Dept. of Physics
Discipline	Physics
Language	Eng
Notes	Bibliography: leaves 109-114.
Abstract	RASTRAN (Remote Acoustic Sediment TRANsport measurement) System 1 has been used in laboratory trials and deployed in nearshore locations as part of several field experiments. The system operates at three frequencies, 1, 2.25 and 5 MHz, over a range of approximately 1 m, with resolution of about 2 cm. A central concern has been the probable errors in suspended sediment concentration and size derived from the backscatter data. An inversion algorithm based on the differences in backscattered pressure amplitude at the three frequencies has been developed. Laboratory experiments, measuring multifrequency backscatter from a turbulent sediment-carrying jet, have been used to calibrate the system and to test the inversion algorithm. Concentration and sizes inverted from field and laboratory data are compared with results from a previously developed algorithm based on signal ratios. Inverted concentrations are also compared with Optical Backscatter Sensor (OBS) data collected during the field experiment. This latest inversion scheme is less sensitive to errors arising from low signal levels, increasing the size/concentration measurement range to regions of lower concentration. The concentration results agree well with the independent OBS data.
Type	Text
Resource Type	Electronic thesis or dissertation
Format	Image/jpeg; Application/pdf
Source	Paper copy kept in the Centre for Newfoundland Studies, Memorial University Libraries
Local Identifier	76118654
Rights	The author retains copyright ownership and moral rights in this thesis. Neither the thesis nor substantial extracts from it may be printed or otherwise reproduced without the author's permission.
Collection	Electronic Theses and Dissertations
Scanning Status	Completed
PDF File	(10.10 MB) -- http://collections.mun.ca/PDFs/theses/Crawford_AnnaM2.pdf
CONTENTdm file name	98657.cpd