GLOSSARY OF MAP PROJECTIONS

All items are listed in the Glossary by alphabetical order. If an item consists of two or more words, the first is always a noun. For example: azimuthal projection is listed as projection, azimuthal. Comma means that the usual order of the word is inverted. The items in Croatian, French and German are listed in the Glossary in the same way. The synonym in English is marked with also. The advantage is given to the first stated item. If there are synonyms in Croatian, French and German, they are separated by a semicolon (;). See refers to the terms that were used in the definition of a certain item or are connected with them.

almucantar
Also: parallel of altitude
Small circle on the surface of the Earth's globe along which all points are equally distant from a point on the globe that we consider a pole of a certain coordinate system.
Note: In astronomy, the circles on the celestial sphere parallel with the horizon.
Hr. almukantarat
Fr. parallele de hauteur
Ger. Netzbreite; Höhenkreis


aspect, normal
Also: aspect, direct
Map projection in which the pole of the normal graticule coincides with the geographic pole.
Remark: The map projection in which the normal graticule is at the same time a map graticule. In the group of perspective projections, these are the projections in which the developable surface axis or the perpendicular to the projection plane coincides with the axis of rotation of a sphere or an ellipsoid.
See:
projection, map; graticule; graticule, normal
Hr. projekcija, uspravna
Fr. projection directe
Ger. Abbildung, normalachsige


aspect, oblique
Also: aspect, skew
Map projection in which the pole of a normal graticule is located in any point between the geographic pole and the equator.
Remark: In the group of perspective projections, these are the projections in which the developable surface axis or perpendicular to the projection plane falls onto the Earth's surface in any point between the geographic pole and the equator.
See:
projection, map; graticule, normal; surface, developable
Hr. projekcija, kosa
Fr. projection, oblique
Ger. Abbildung, schiefachsige


aspect, transverse
Map projection in which the pole of the normal graticule is on the equator.
Remark: In the group of perspective projections, these are the projections in which the developable surface axis or the perpendicular to the projection plane is placed in the equator plane.
See:
projection, map; graticule, normal
Hr. projekcija, poprecna
Fr. projection transverse
Ger. Abbildung, querachsige


axis of rotation
The straight line around which a sphere is created by the rotation of a semicircle, or a rotational ellipsoid is created by the rotation of a semiellipse.
Remark: A sphere and a rotational ellipsoid are surfaces by means of which the Earth's form is usualy approximated. The axis of rotation runs through the poles.
Hr. os, obrtna; os rotacije
Fr. axe de rotation
Ger. Rotationsachse


equator
The largest geographic parallel.
See:
parallel, geographic
Hr. ekvator
Fr. équateur
Ger. Äquator


directions, principal
Also: directions, base
Two mutually perpendicular straightlines in a point on the ellipsoid or sphere and the appropriate mutually perpendicular straightlines in the plane of projection along which the linear scale has extreme values - maximum and minimum.
See:
scale, linear
Hr. pravci, glavni
Fr. directions principales
Ger. Hauptverzerrungsrichtungen


geodesic
Also: line, geodesic; line, geodetic
Geometrically interpreted, it is the shortest line connecting two points of a not too large area on a surface.
See:
orthodrome
Hr. linija, geodetska
Fr. ligne géodésique
Ger. Linie, geodätische


graticule
Image of coordinate lines in a plane of projection.
Note: The graticule presented by the lines of meridians and parallels is called the basic graticule.
Hr. mreza, kartografska
Ger. Kartennetz


graticule, normal
The graticule in which the coordinate lines assume the simplest form.
Remark: The normal graticule on the sphere is made of a system of verticals and almucantars. The pole of this system coincides with the geographic pole, it is located on the equator or occupies any position between the geographic pole and equator.
See:
graticule; vertical; almucantar
Hr. mreza, normalna kartografska


latitude, geographic
(1) Generic (general) term for geodetic and astronomical latitude. (2) The angle between the equatorial plane and the direction of the normal to the Earth's sphere through the given point; regarded as positive Northwards. The designation φ.
Remark: The geographic latitude for an ellipsoid can be defined analogously.
Hr. sirina, geografska
Fr. latitude géographique
Ger. Breite, geographische


line, rhumb
Also: line of constant bearing; loxodrome
A line on the rotational surface intersecting all meridians at the same angle.
Remark: Ships sail along the rhumb line when sailing continuously in the same course on their way between two positions.
See:
meridian
Hr. loksodroma
Fr. loxodromie
Ger. Loxodrome


longitude, geographic
(1) Generic (general) term for geodetic or astronomic longitude. (2) The angle between the plane of the prime meridian and the plane of the meridian through the given point; it is considered positive Eastward. Denoted by λ.
Hr. duzina, geografska
Fr. longitude géographique
Ger. Länge, geographische


loxodrome
See: line, rhumb


meridian
(1) Generic (general) term for astronomic and geodetic meridian. (2) A line on the Earth's sphere obtained by the intersection of the sphere with the half-plane with the boundary straightline coinciding with the sphere rotational axis.
Remark: The meridian on an ellipsoid can be defined analogously.
See:
longitude, geographic
Hr. meridijan
Fr. méridien
Ger. Meridian


orthodrome
Geodesic on a sphere.
Note: On a sphere, the orthodromes are the arcs of great circles.
See:
geodesic
Hr. linija, geodetska
Fr. orthodrome
Ger. Orthodrome


parallel, geographic
(1) Generic (general) term for astronomic and geodetic parallel. (2) The line on the Earth's sphere obtained by intersection the sphere with the plane perpendicular to the rotational axis of the sphere.
See:
latitude, geographic
Hr. paralela
Fr. parallele de latitude
Ger. Breitenkreis; Parallelkreis


plane, equatorial
The plane containing the equator.
Hr. ravnina, ekvatorska
Fr. plan d'équateur
Ger. Äquatorebene


plane of projection
The plane into which the surface of the Earth or a celestial body, assumed to be an ellipsoid or sphere, is mapped (projected).
Hr. ravnina, projekcijska
Fr. plan de projection
Ger. Abbildungsebene


projection, arbitrary
Map projection that is neither equivalent, nor conformal, nor equidistant. In this projection the surface of the Earth's ellipsoid or sphere is mapped into the plane under some special conditions.
See:
projection, map; projection, conformal; projection, equivalent; projection, equdistant
Hr. projekcija, uvjetna
Fr. projection aphylactique
Ger. Abbildung, vermittelnde


projection, azimuthal
Also: projection, zenithal
Map projection on which the meridians of normal aspect are mapped as the straight lines intersecting in one point, at the angles equal to the difference between the corresponding longitudes of the meridians and the parallels as arcs of concentric circles with the centre in the meridian intersection.
Remark: Perspective azumuthal projection - special type of azimuthal projection in which the Earth is considered to be a sphere, and the points from the sphere are projected following the laws of linear perspective from the point of view to a projection plane. The projection plane is perpendicular to the line connecting the point of view with the globe centre.
See:
projection, map; aspect, normal; meridian; parallel, geographic
Hr. projekcija, azimutalna
Fr. projection azimutale
Ger. Azimutalabbildung


projection, conformal
Also: projection, orthomorphic
Map projection preserving angles.
Remark: Map projection in which there are no angular distortions. In conformal projection the linear scale in every point is equal in all directions, so in these projection the similarity of infinitesimal parts of the representation is preserved.
See:
projection, map; scale, linear
Hr. projekcija, konformna
Fr. projection conforme
Ger. Abbildung, konforme; Abbildung, winkeltreue


projection, conic
Also: projection, conical
Map projection on which the meridians of normal aspect are mapped as the straight lines intersecting in one point at the angles proportional to the difference between the corresponding longitudes of the meridians and parallels as the arcs of concentric circles with the centre in the meridian intersection.
Remark: Perspective conic projection - perspective projection in which the cone is used as a developable surface.
See:
projection, map; projection, perspective; aspect, normal; meridian; parallel, geographic
Hr. projekcija, konusna; projekcija, stozasta
Fr. projection conique
Ger. Kegelabbildung


projection, cylindrical
Map projection on which meridians of normal aspect are mapped by straight parallel lines at the distance proportional to the differences between the coresponding longitudes of the meridians, and parallels by straight parallel lines orthogonal to meridians, at the distances depending on mapping conditions.
Remark: Perspective cylindrical projections - perspective projection in which the cylinder is used as a developable surface.
See:
projection, perspective; aspect, normal; meridian; parallel, geographic
Hr. projekcija, cilindricna; projekcija, valjkasta
Fr. projection cylindrique
Ger. Zylinderabbildung


projection, equidistant
Map projection preserving distances in a particular direction.
Remark: Map projection on which the linear scale along one principal direction is equal to the unit, i.e. in any point there exists a direction with no linear distortion along it.
See:
scale, linear; directions, principal
Hr. projekcija, ekvidistantna
Fr. projection équidistante
Ger. Abbildung, abstandstreue


projection, equivalent
Also: projection, equal-area; projection, authalic
Map projection preserving areas.
Remark: An equivalent map projection has the property that in any point the area scale is equal to 1, i.e. there are no area distortions in any point.
See:
projection, map
Hr. projekcija, ekvivalentna
En. projection, equivalent; projection, equal-area
Fr. projection équivalente
Ger. Abbildung, flächentreue


projection, Gauss-Krüger
Also: projection, Transverse Mercator
Conformal transverse cylindrical projection with the property that the central meridian of the given area is mapped as a straight line and serves as the x axis of the rectangular coordinate system in the plane; the central meridian is mapped without linear distortions or the linear scale along this meridian is constant.
Remark: In English speaking area, the projection is known as the Transverse Mercator projection.
See:
projection, conformal; aspect, transverse; projection, cylindrical
En. projekcija, Gauss-Krügerova
Fr. projection de Gauss-Krüger
Ger. Gauss-Krüger-Abbildung


projection, gnomonic
Also: projection, central
Perspective azimuthal projection in which the point of view is in the globe centre.
Remark: In this projection, the orthodromes are represented as straight lines.
See:
projection, azimuthal; orthodrome
Hr. projekcija, centralna; projekcija, gnomonska
Fr. projection gnomonique
Ger. Zentralprojektion; Abbildung, gnomonische


projection, map
The method of representing the Earth or a celestial body, assumed to be an ellipsoid or sphere, in a plane. It is mostly defined by map projection equations x = f1(φ, λ), y = f2(φ, λ), where φ, λ are geographic coordinates on the ellipsoid or sphere, and x, y the coordinates in the projection plane. It can also be defined with the table of coordinates or the description of map graticule construction. According to the distortion characteristics, they are classified into conformal, equivalent, equidistant and arbitrary projections. Depending on the orientation of the normal graticule (location of the pole of the coordinate system adopted), map projections can be divided into normal (direct), transverse and oblique aspects of the projections. According to the shape of the normal graticule, they are classified into conic, cylindrical, azimuthal, pseudoconic, pseudocylindrical, polyconic, and other projections. They are often named after their authors, e.g. Mercator, Sanson, Robinson. As a special group of map projections we separate geodetic projections, i.e. projections needed in state surveys.
See:
graticule, normal; aspect, normal
Hr. projekcija, kartografska
Fr. projection cartographique
Ger. Abbildung, kartographische


projection, Mercator
Conformal cylindrical projection.
Remark: Normal aspect has special importance in navigation, because the rhumb lines are represented as straight lines in this projection. Transverse aspect is used in many countries for official cartography. Universal Transverse Mercator (UTM) is used in military (NATO).
See:
projection, cylindrical; projection, conformal; aspect, normal; aspect, transverse; line, rhumb; UTM
Hr. projekcija, Mercatorova
Fr. projection de Mercator
Ger. Mercatorabbildung


projection, ortographic
Perspective azimuthal projection in which the point of view is placed in infinity, so the projection rays are mutually parallel.
See:
projection, azimuthal
Hr. projekcija, ortografska
Fr. projection orthographique
Ger. Abbildung, orthographische; Parallelprojektion


projection, perspective
Map projection in which the points from the ellipsoid or sphere are projected following the laws of linear perspective from the point of view into the projection plane or developable surface.
Remark: Out of perspective projections, the azimuthal projections are most often applied in practice, so the term perspective projection often denotes only this group of projections.
See:
projection, map; plane of projection; surface, developable
Hr. projekcija, perspektivna
Fr. projection perspective
Ger. Projection


projection, polyconic
Map projection on which the meridians of normal aspect are mapped as curves symmetrical about the straight central meridian, and parallels as nonconcentric circular arcs with centres on the central meridian.
See:
projection, map; aspect, normal; meridian; parallel, geographic
Hr. projekcija, polikonusna
Fr. projection policonique
Ger. Abbildung, polykonische


projection, polyhedric
Map projection in which the Earth's surface is divided by meridians and parallels into ellipsoidal trapeziums; each trapezium is mapped into the plane separately, providing that its sides are mapped as the parts of the straight lines with the lengths equal to the lengths of the arcs of adequate meridians and parallels.
See:
projection, map; meridian; parallel, geographic
Hr. projekcija, poliedarska
Fr. projection polyedrique
Ger. Polyederabbildung


projection, pseudoconic
Map projection in which the meridians of the normal aspect are mapped as curves symmetrical about the straight central meridian and parallels as the arcs of concentric circles with the centre on the central meridian.
See:
aspect, normal
Hr. projekcija, pseudokonusna
Fr. projection mériconique
Ger. Abbildung, unechtkonische


projection, pseudocylindrical
Map projection in which the meridians of the normal aspect are mapped as the curves symmetrical about the straight central meridian, and the parallels as mutually parallel straight lines perpendicular to the central meridian.
See:
aspect, normal
Hr. projekcija, pseudocilindricna
Fr. projection méricylindrique
Ger. Abbildung, unechtzylindrische


projection, transverse Mercator
(1) Map projection that is a Mercator projection and in transverse aspect. (2) In the English speaking area it is the name for the Gauss-Krüger projection.
See:
projection, Mercator; aspect, transverse; projection, Gauss-Krüger
Hr. projekcija, poprecna Mercatorova
Fr. projection transverse de Mercator
Ger. Mercatorabbildung, transversale


scale, linear
Also: scale factor
The ratio of the differential of the arc length in the plane of projection and the corresponding defferential on the surface of the Earth or a celestaial body, assumed to be an ellipsoid or sphere.
Note: Linear scale varies from point to point on a map, and is diferent in every direction in any given point, which is why we differentiate: linear scale along the meridian, linear scale along the parallel, linear scale along principal directions. If at some point in a certain direction there are no linear distortions, the linear scale is equal to the unit.
See:
directions, principal
Hr. mjerilo duzina; mjerilo, linearno
Fr. échelle des longueurs
Ger. Längenmaßstab


surface, developable
The surface that can be developed into the plane (cone and cylinder) into which the points are projected from the globe or ellipsoid surface in perspective conic and cylindrical projections.
See:
projection, perspective
Hr. ploha, pomocna
Fr. surface auxiliaire de projection
Ger. Hilfsabbildungsfläche


UTM (Universal Transverse Mercator)
Sixty systems of the transverse Mercator projection with each of them covering the area of six degrees of longitude. The point of origin in each system is in the intersection of the central meridian with the longitude 3º, 9º, 15º etc. and the equator. Linear scale along the central meridian is 0.9996.
See:
projection, transverse Mercator
Hr. UTM (projekcija, univerzalna poprecna Mercatorova)
Fr. projection UTM
Ger. UTM-Abbildung


vertical
Every great circle on the sphere passing through the pole of the adopted coordinate system.
Remark: In astronomy, great circles on the sky sphere passing through zenith.
Hr. vertikal
Fr. cercle vertical
Ger. Netzmeridian; Vertikalkreis


References:

Bugayevskiy, L. M., Snyder, J. P. (1995): Map Projections - A Reference Mannual, Taylor & Francis, London, Bristol.
Canters, F. (2002): Small-scale Map Projection Design, Taylor & Francis, London and New York.
Francula, N., Lapaine, M. (ed. 2003): Geodetic Dictionary (Geodetski rjecnik), State Geodeteic Administration, and Faculty of Geodesy, University of Zagreb.

Nedjeljko Francula, Miljenko Lapaine