Page 222 - Green - Maritime Archaeology: A Technical Handbook. 2nd ed
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Chapter 6: Photogrammetric Techniques 201
was distorted. Because the grid was lightweight it had a lot of flexibility and it distorted easily. The rigid grid, however, had much higher accuracy all round. Figure 6.18 shows the extent of the reliability of the system. The average difference in the X, Y, and Z coordinates between the true posi- tion and the PhotoModeler position is Dx = 2.3 mm, Dy = 2.6 mm, and Dz = 2.9 mm. This means that the individual accuracy for any single point, using PhotoModeler, is exceptionally high.
Figure 6.18 Plot of the 1-m grid frame showing the reliability of the measurements.
 































































































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