USGS MIPS Map Projection Parameters





This document describes the user input required for USGS MIPS programs which have map projection parameters. That is, programs dealing with georeferenced images and/or other data sets. It is well beyond the scope of this document to describe the fundamentals of projections, when and why to use a specific projection over another, what values should be used for the standard parallels, central meridian, etc. However, Map Projecions - A Working Manual by John P. Snyder, U.S. Geological Survey Profesional Paper 1395, can be used as a reference for these types of questions.

There are four sections to this document. Each section covers a different set of user input related to map projections. The sections are:

Note that all programs dealing with map projections will have a separate user input for each of the above items; however, they are not required to have all four components.

Selecting the Map Projection

This prompt asks the user for a map projection to use when georeferencing images or other data. There are currently 24 projections to select from. Given below is the parameter name used to select the projection followed by the name of the projection and possible alternative names.

GEOGGeographic
Latitude/Longitude
UTMUniversal Transverse Mercator
ALBEAlbers Equal-Area Conic
LAMBLambert Conformal Conic
Conical Orthomorphic
MERCMercator
TRANTransverse Mercator
Gauss Conformal
Gauss-Kruger
STERStereographic
LAMALambert Azimuthal Equal-Area
Azimutal Equal-Area
Zenithal Equal-Area
AZEQAzimuthal Equidistant
SINUSinusoidal
Mercator Equal-Area
Sanson-Flamsteed
SIMPEquidistant Cylindrical (CLAT = Any)
Simple Cylindrical (CLAT = 0)
Plate Carree (CLAT = 0)
SOMSpace Oblique Mercator
POLAPolar Stereographic
POLYPolyconic
American Polyconic
ECON1
ECON2
Equidistant Conic
Simple Conic
Conic
GNOMGnomonic
Gnomic
Central
POINGeneral Vertical Near-side Perspective
MILLMiller Cylindrical
VANGVan Der Grinten I
OMER1
OMER2		Oblique Mercator
Hotine
Rectified Skew Orthomorphic
ROBIRobinson


Selecting the Ellipsoid

This prompt asks the user for an ellipsoid (the shape of the earth) to use when georeferencing images or other data. The user has the choice of selecting from twenty pre-defined ellipsoids or setting the equatorial radius (semi-major axis) and the eccentricity to any desired value by using the RADIUS and ECCENTRICITY parameters.

Note that the map projection selected may not need or support ellipsoids. Also, certain projections (e.g., sinusoidal, gnomonic, etc) are based solely upon a sphere and will only ask for the radius and not the eccentricity.

Below is the list of pre-defined ellipsoids with the parameter name used for selecting, the name of the ellipsoid, the radius in meters, and the eccentricty squared.

CLARKClarke 18666378206.40.006768658
CLARK2Clarke 18806378249.1450.006803511
WGS84World Geodetic System (WGS) 19846378137.00.006694380
WGS72World Geodetic System (WGS) 19726378135.00.006694318
WGS66World Geodetic System (WGS) 19666378145.00.006694542
BESSELBessel6377397.1550.006743722
INT67New International 19676378157.50.006694551
INT09International 19096378388.00.006722670
GRS80Geodetic Reference System (GRS) 19806378137.00.006694380
EVERESTEverest6377276.34520.006637847
MODEModified Everest6377304.0630.006637847
AIRYAiry6377563.3960.006670540
ASIASoutheast Asia6378155.00.006934216
AUSTAustralian National6378160.00.006694542
KRASSKrassovsky6378245.00.006693422
HOUGHHough6378270.00.006722670
MERC60Mercury 19606378166.00.006693422
MERC68Modified Mercury 19686378150.00.006693422
SPHERESphere6370997.00.0


Setting the Projection Parameters



Selecting a Latitude/Longitude Window

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