Description
Ney is a modified Lambert conformal conic projection. The projection slightly expands the parallels to create complete concentric circles centered at the pole, resulting in azimuthal polar map view. It is an appropriate projection to map areas near the pole. The projection uses two standard parallels, where one defines which hemisphere (north or south) is projected in the center.
The mathematics for the Ney modified conic projection were introduced by C. H. Ney in 1949. It is available in ArcGIS Pro 1.0 and later and in ArcGIS Desktop 10.0 and later.
Projection properties
The subsections below describe the Ney modified conic projection properties.
Graticule
Ney modified conic is an azimuthal projection. The graticule of Ney projection is similar to the graticules of other azimuthal projections in polar aspects. The parallels are projected as concentric circles centered at the pole. The meridians are shown as straight lines, originating at the pole, intersecting perpendicularly with the parallels. The opposite pole is not projected.
Distortion
Ney modified conic is a conformal map projection. It does not maintain true directions, but angles and shapes are maintained at infinitesimal scale. Along the two standard parallels there is no distortion. Area, distance, and scale distortions grow rapidly with the distance from the standard parallels. Distortion values are the same along a particular parallel.
Usage
The Ney modified conic projection is only appropriate to map areas near one of the poles. Typically the first standard parallel is set to either 71° or 74° north or south and the other standard parallel is set to 89° 59' 58" (89.99944444°). Distortion is small up until about 25° to 30° from the pole. Other areas are too distorted to be displayed on the map.
Limitations
The Ney modified Lambert conformal conic projection does not project the opposite pole. Areas more than 30° from the pole are severely distorted. The implementation of this projection in ArcGIS does not display the whole globe.
Parameters
Ney modified conformal conic parameters are as follows:
- False Easting
- False Northing
- Central Meridian
- Standard Parallel 1
- Standard Parallel 2
- Scale Factor
- Latitude Of Center
Sources
Ney, C. H. (1949). "The modified Lambert conformal projection for polar areas." Canadian Journal of Research, 27, p. 269-283.
User's Guide for Mensuration Services Program (MSP) Geographic Translator (GEOTRANS) Version 3.8 (2019). Available online: https://earth-info.nga.mil/GandG/update/wgs84/apps/geotrans/current-version/docs/MSP_GeoTrans_Users_Guide%203.8.pdf [accessed on 18 October 2019].