Proj: Oblique Mercator specifying two points on central line

What is Oblique Mercator used for?

Usage. Hotine oblique Mercator projection is appropriate for mapping large-scale areas or smaller areas with an oblique orientation that do not follow a north-south or east-west predominant extent.

What are the strengths of the oblique Mercator?

The oblique Mercator map projection is an adaptation of the standard Mercator projection. The oblique version is sometimes used in national mapping systems. When paired with a suitable geodetic datum, the oblique Mercator delivers high accuracy in zones less than a few degrees in arbitrary directional extent.

What is the use of oblique and transverse projection?

An oblique cylindrical projection. Less than half of the actual map projection is displayed here. As with the transverse cylindrical map projection, the oblique cylindrical map projection wraps around the earth using a great circle other than the equator and only one hemisphere is usually displayed.

Where is oblique projection used?

Oblique projections can be useful for objects with curves if those faces are oriented parallel to the projection plane. Figure 19.2. Oblique projection. For an orthographic projection, the projector is perpendicular and the length of the line L is zero, reducing the projection matrix to the identity.

What is the purpose of an oblique view?

Conclusion: In the distal extremities, the oblique view uniquely reveals abnormalities and increases the confidence of the final radiographic diagnosis when the oblique view is interpreted along with frontal and lateral radiographs.

What are the 3 principles of oblique drawing?

To draw it correctly in oblique projection three main rules must be followed:

• Draw the front or side view of the object.
• All measurements drawn backwards are half the original measurement.
• 45 degrees is the angle for all lines drawn backwards.

What are the two types of oblique projection?

Following are the two types of oblique projection according to construction.

• Cavalier Oblique Drawing.
• Cabinet Oblique Drawing.
• First of all orthographic projections are drawn on one side of the sheet.

What are the problems with oblique projection?

Cons: objects can look distorted if careful choice not made about position of projection plane (e.g., circles become ellipses) lack of foreshortening (not realistic looking)

What is the purpose of an oblique radiographic projection?

Examination/Imaging



Preoperative oblique-projection plain radiograph films are valuable for evaluation of the pedicle size. In an oblique projection, the contralateral pedicle is seen as an oval projected onto the vertebral body, showing the outer and inner diameter of the pedicle.

What is the main use of Mercator projection?

This projection is widely used for navigation charts, because any straight line on a Mercator projection map is a line of constant true bearing that enables a navigator to plot a straight-line course.

Why do people use Mercator?

The reason Web Mercator was suitable as the basis for early web mapping is that it creates a convenient square shape for the entire world if it is truncated at approximately 85° North and South of the Equator. Wherever you are on the map, up is due north, down is due south and west and east are always left and right.