# Vertical near-side perspective

## Description

The vertical near-side perspective is an azimuthal projection projecting Earth's surface from a finite distance to a plane, unlike the orthographic projection, which projects from an infinite distance. This map projection gives the overall effect of the view from a satellite. It was known by the Egyptians and Greeks. It is available in ArcGIS Pro 1.0 and later and in ArcGIS Desktop 8.1.1 and later.

## Projection properties

The subsections below describe the vertical near-side perspective projection properties.

### Graticule

The vertical near-side perspective is an azimuthal projection.

In the polar aspect, the meridians project as straight lines originating at the pole in the center. Angles between them are true. Parallels are shown as unequally spaced concentric circular arcs. Their spacing decreases with the distance from the center. The opposite pole cannot be projected. The graticule is symmetric across any meridian.

In the equatorial aspect, the equator and the central meridian are projected as two perpendicular straight lines. Other meridians are elliptical arcs. Their spacing decreases away from the central meridian. All parallels are also elliptical arcs, perpendicular to the central meridian. Their spacing decreases away from equator. The poles and meridians 90° away are never displayed. The graticule is symmetric across the equator and the central meridian.

In the oblique aspect, only the central meridian and antimeridian project as straight lines. The other meridians are unequally spaced elliptical arcs intersecting at the nearest pole to the center, which is projected as a point. The parallels are unequally spaced elliptical arcs and their spacing decreases away from the projection's center. The graticule is symmetric across the central meridian.

### Distortion

The vertical near-side perspective projection is neither conformal nor equal-area. Shapes, areas, distances, directions, and angles are all generally distorted. Only the center of the projection is free of distortion. The distortion increases away from the center. Extreme distortion exists near the edge of the map outline.

## Usage

The vertical near-side perspective projection, mostly in an oblique aspect, can be used for pictorial views of the Earth and other planets from satellites in space.

## Limitations

The vertical near-side perspective projection is limited to less than a hemisphere. The range depends on the height parameter. The farther away the view point is, the bigger the portion of a hemisphere is displayed.

## Parameters

Vertical near-side perspective parameters are as follows:

• False Easting
• False Northing
• Longitude of Center
• Latitude Of Center
• Height

## Sources

Snyder, J. P. (1987). Map Projections: A Working Manual. U.S. Geological Survey Professional Paper 1395. Washington, DC: United States Government Printing Office.

Snyder, J. P. (1993). Flattening the Earth. Two Thousand Years of Map Projections. Chicago and London: University of Chicago Press.

Snyder, J. P. and Voxland, P. M. (1989). An Album of Map Projections. U.S. Geological Survey Professional Paper 1453. Washington, DC: United States Government Printing Office.