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. Collected reprints, Essa Institute for Oceanography. Oceanography Figure 5-1. Principle of the Multiplexing Stereoplotter. (Photo courtesy of the Geological Survey.) dimensions. This projection-viewing system permits, through filtering, the viewing of one frame with one eye and the other frame with the other eye. A table serves as the x-y plane and is perpendicular to the axis of pro- jection, which is the z axis. The plane of focus is parallel to and above this table. The scales of both the x-y plane and the z axis are functions of the ratio b/h. However, the z scale is a
. Collected reprints, Essa Institute for Oceanography. Oceanography Figure 5-1. Principle of the Multiplexing Stereoplotter. (Photo courtesy of the Geological Survey.) dimensions. This projection-viewing system permits, through filtering, the viewing of one frame with one eye and the other frame with the other eye. A table serves as the x-y plane and is perpendicular to the axis of pro- jection, which is the z axis. The plane of focus is parallel to and above this table. The scales of both the x-y plane and the z axis are functions of the ratio b/h. However, the z scale is also a function of the focal lengths of the photographing and projecting cameras, and hence the two scales can be, but are not necessarily, the same. Fig. 5-1 shows a small circular projection screen mounted on a suitable fixture and aligned parallel to the image plane. The screen's center serves as the reference point for either tracking the image contours or measuring elevations. Directly below this point, and in contact with the table, is a pencil which traces the horizontal path of the reference point. The fixture can be moved freely in the x-y plane and the screen can be moved vertically, through gearing, by a graduated dial. The dial readings are convertible to true height differences from an arbitrary zero reference plane. Since the vertical scale can be adjusted to fit the vertical range of the screen, the reference point can be made to coincide with any desired point in the image. By moving the reference point along the curves of coinci- dence, those image elevations are sketched, and thus the entire relief can be contoured at any desired Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Institute for Oceanography; Atlantic Oceanographic Laboratories (U. S. ); Pacific Oceanographic Laborator
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