A simulation study of the effect of target motion on sighting estimates of minke whale population density

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dc.contributor.advisorButterworth, Doug S
dc.contributor.advisorUnderhill, Leslie G
dc.contributor.authorBasson, Marinelle
dc.date.accessioned2016-02-08T07:08:23Z
dc.date.available2016-02-08T07:08:23Z
dc.date.issued1983en_ZA
dc.description.abstractLine transect methods used to estimate population density assume stationarity of targets. Violation of this assumption leads to overestimation of the true density. A simulation study based on a hazard-rate model is used to assess the resulting bias. The model is calibrated to generate sighting data resembling real data from minke whale sighting surveys. The procedure currently used to calculate a corrected negative exponential density estimate from sighting data is duplicated using simulated data. The resulting estimates are compared to the true population density determined by the simulation. Results reveal that in the case considered, the method of calculating the g(O) factor (which corrects for the fact that all animals on the trackline are not sighted) leads to a greater degree of overestimation than the effect of target motion at 3 knots. Shortcomings of the model are pointed out and possible improvements suggested. It is also suggested that further research be focused initially on the calculation of the g(O) correction factor rather than on effects of target motion.en_ZA
dc.identifier.apacitationBasson, M. (1983). <i>A simulation study of the effect of target motion on sighting estimates of minke whale population density</i>. (Thesis). University of Cape Town ,Faculty of Science ,Department of Mathematics and Applied Mathematics. Retrieved from http://hdl.handle.net/11427/16843en_ZA
dc.identifier.chicagocitationBasson, Marinelle. <i>"A simulation study of the effect of target motion on sighting estimates of minke whale population density."</i> Thesis., University of Cape Town ,Faculty of Science ,Department of Mathematics and Applied Mathematics, 1983. http://hdl.handle.net/11427/16843en_ZA
dc.identifier.citationBasson, M. 1983. A simulation study of the effect of target motion on sighting estimates of minke whale population density. University of Cape Town.en_ZA
dc.identifier.ris TY - Thesis / Dissertation AU - Basson, Marinelle AB - Line transect methods used to estimate population density assume stationarity of targets. Violation of this assumption leads to overestimation of the true density. A simulation study based on a hazard-rate model is used to assess the resulting bias. The model is calibrated to generate sighting data resembling real data from minke whale sighting surveys. The procedure currently used to calculate a corrected negative exponential density estimate from sighting data is duplicated using simulated data. The resulting estimates are compared to the true population density determined by the simulation. Results reveal that in the case considered, the method of calculating the g(O) factor (which corrects for the fact that all animals on the trackline are not sighted) leads to a greater degree of overestimation than the effect of target motion at 3 knots. Shortcomings of the model are pointed out and possible improvements suggested. It is also suggested that further research be focused initially on the calculation of the g(O) correction factor rather than on effects of target motion. DA - 1983 DB - OpenUCT DP - University of Cape Town LK - https://open.uct.ac.za PB - University of Cape Town PY - 1983 T1 - A simulation study of the effect of target motion on sighting estimates of minke whale population density TI - A simulation study of the effect of target motion on sighting estimates of minke whale population density UR - http://hdl.handle.net/11427/16843 ER - en_ZA
dc.identifier.urihttp://hdl.handle.net/11427/16843
dc.identifier.vancouvercitationBasson M. A simulation study of the effect of target motion on sighting estimates of minke whale population density. [Thesis]. University of Cape Town ,Faculty of Science ,Department of Mathematics and Applied Mathematics, 1983 [cited yyyy month dd]. Available from: http://hdl.handle.net/11427/16843en_ZA
dc.language.isoengen_ZA
dc.publisher.departmentDepartment of Mathematics and Applied Mathematicsen_ZA
dc.publisher.facultyFaculty of Scienceen_ZA
dc.publisher.institutionUniversity of Cape Town
dc.subject.otherMathematical Statisticsen_ZA
dc.subject.otherOperations Researchen_ZA
dc.titleA simulation study of the effect of target motion on sighting estimates of minke whale population densityen_ZA
dc.typeMaster Thesis
dc.type.qualificationlevelMasters
dc.type.qualificationnameMScen_ZA
uct.type.filetypeText
uct.type.filetypeImage
uct.type.publicationResearchen_ZA
uct.type.resourceThesisen_ZA
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