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Abstract:
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In the method of creating digital terrain model (DTM) by using digital photogrammetry,
the picket sampling interval (PSI) plays an important role since it strongly influences on the
production effectiveness and on the accuracy of created DTMs. The optimal value of PSI must be
balanced between requirements of effectiveness and of accuracy.
This research is focused on the influence of PSI on root mean square error (RMSE) of created
DTM and on the number of error pickets (caused by limitation of image matching technique) that
must be checked and corrected manually. Based on the results obtained in four experimental areas
of Vietnam (Co Loa, Duong Lam, Ba Vi, and Lang Son), the paper has proposed an empirical
equation for choosing optimal PSI: PSI = k P×Ma , where P is the scan resolution (μm); a M is
the denominator of airphoto scale; k is a coefficient depending on the characteristics of topography. |