projeksiyon sistemleri

What is a projection?What is a projection?• A map projection is used to portray all A map projection is used to portray all

or part of the spherical Earth on a flat or part of the spherical Earth on a flat surface. This cannot be done without surface. This cannot be done without some distortionsome distortion

• Every projection has its own set of Every projection has its own set of advantages and disadvantages. There is advantages and disadvantages. There is no "best" projectionno "best" projection

• In GIS we must select the one best In GIS we must select the one best suited to our needs, reducing distortion suited to our needs, reducing distortion of the most important featuresof the most important features

ChartChart PProjectionsrojectionsThree main typesThree main types

LAMBERT (LAMBERT (ConicConic))GNOMONIC (GNOMONIC (AzimuthalAzimuthal) ) MERCATOR (MERCATOR (CylindricalCylindrical))

LAMBERT (Conic) projections

result from projecting a spherical surface onto a cone.

LAMBERT (Conic) ProjectionsLambert Conformal Conic projection

•Area, and shape are distorted away from standard parallels. Directions are true in limited areas. Used for maps of North America. Lambert Conformal Conic projections are used for

rectangular zones with a larger east-west extent. Ex: North Carolina, Tennessee

GNOMONIC (Azimuthal)GNOMONIC (Azimuthal)

Azimuthal—Geometrically projected on a plane. Point of projection is the center of a globe.

• UsedUsed by some navigators to find the shortest path by some navigators to find the shortest path between two points. Used in seismic work because between two points. Used in seismic work because seismic waves tend to travel along great circles.seismic waves tend to travel along great circles.

• Any straight line drawn on the map is on a Any straight line drawn on the map is on a great great circlecircle, but , but directionsdirections are true are true onlyonly from center from center point of projection. Map is perspective (from the point of projection. Map is perspective (from the center of the Earth onto a tangent plane) but center of the Earth onto a tangent plane) but notnot conformal, equal area, or equidistant.conformal, equal area, or equidistant.

• Considered to be the oldest projection. Ascribed to Considered to be the oldest projection. Ascribed to Thales, the father of abstract geometry, who lived Thales, the father of abstract geometry, who lived in the 6th century B.C.in the 6th century B.C.


MercatorMercator• UsedUsed for navigation for navigation

or maps of or maps of equatorial regions. equatorial regions.

• Any straight line on Any straight line on the map is athe map is a rhumb rhumb lineline (line of (line of constant direction).constant direction).

• DirectionsDirections along a along a rhumb line are true rhumb line are true between between anyany two two points on map points on map

Gerardus Mercator (1512-1594)

MERCATOR (Cylindrical) projections

result from projecting a spherical surface onto a cylinder.

MERCATOR (Cylindrical) projections

.

Features of MercatorFeatures of Mercator• DistancesDistances are true are true onlyonly along Equator, but along Equator, but

are reasonably correct within 15are reasonably correct within 15°° of Equator. of Equator.• Areas and shapesAreas and shapes of large areas are of large areas are

distorted.distorted.• DistortionDistortion increases away from Equator and increases away from Equator and

is extreme in polar regions. The map is is extreme in polar regions. The map is notnot perspective, equal area, or equidistant.perspective, equal area, or equidistant.

• Equator and other parallels are straight lines Equator and other parallels are straight lines and meet meridians at right anglesand meet meridians at right angles

WHAT IS A NAUTICAL CHART?

A Nautical Chart is a graphic portrayal of the marine environment.

In addition to its basic elements, a chart is a working document used by the mariner both as a "road map" and worksheet and is essential

for safe navigation.

Chart ScaleChart ScaleThe size of the area represented in a chart varies The size of the area represented in a chart varies

in according to the scale of the chartin according to the scale of the chartCharts with a small scale will cover a large areaCharts with a small scale will cover a large areaCharts with a large scale will cover a small areaCharts with a large scale will cover a small area

1/3.000.000

1/100.000

1/40.000

1/1

1/900.000

1/150.000

TURKISH NAUTICAL CHART

GENEL HARİTALAR : 1/600.000 – 1/150.000

PARÇA HARİTALAR : 1/150.000 – 1/50.000

PORTOLONLAR : 1/50.000 den büyük

- - two digits

- - - three digits

- - - - four digits

1123212291

TURKISH NAUTICAL CHART

Turkish Nautical charts are divided 3 region

11

22

33

29

213

12

1013

11

16

15

19 20

16

9

NoNo AçıklamasıAçıklaması

11 Haritanın Ulusal NumarasıHaritanın Ulusal Numarası

22 Haritanın Seyir Yardımcılarına Uygun.Haritanın Seyir Yardımcılarına Uygun.

33 Haritanın Uluslararası NumarasıHaritanın Uluslararası Numarası

99 Köşe KoordinatlarıKöşe Koordinatları

1010 Harita Başlığı veya Adı Harita Başlığı veya Adı

1111 Haritanın Projeksiyon TipiHaritanın Projeksiyon Tipi

1212 Haritayı Hazırlayan Kuruluşun AmblemiHaritayı Hazırlayan Kuruluşun Amblemi

1313 Haritanın ÖşçeğiHaritanın Öşçeği

1515 Büyük Ölçekli Haritalarda Diğer ÖlçeklerBüyük Ölçekli Haritalarda Diğer Ölçekler

1616 Uyarı NotlarıUyarı Notları

1919 Bitişik veya Devam Eden Harita No’suBitişik veya Devam Eden Harita No’su

2020 Diğer Notik BilgilerDiğer Notik Bilgiler

213

18

9

57 6a

8

17

14


11 Haritanın Ulusal NumarasıHaritanın Ulusal Numarası

22 Haritanın Seyir Yardımcılarına Uygun.Haritanın Seyir Yardımcılarına Uygun.

33 Haritanın Uluslararası NumarasıHaritanın Uluslararası Numarası

44 Haritayı Hazırlayan KuruluşHaritayı Hazırlayan Kuruluş

55 Telif HakkıTelif Hakkı

66 Yeni Yayın TarihiYeni Yayın Tarihi

6a6a Baskı TarihiBaskı Tarihi

619

4


77 Küçük DüzeltmelerKüçük Düzeltmeler

88 Haritanın İç kenarlarının BoyutlarıHaritanın İç kenarlarının Boyutları

99 Köşe KoordinatlarıKöşe Koordinatları

1414 Büyük Ölçekli Haritalarda Diğer Ölç.Büyük Ölçekli Haritalarda Diğer Ölç.

1717 Kaynak ve Veri DiyagramıKaynak ve Veri Diyagramı

1818 Büyük Ölçekli ReferanslarBüyük Ölçekli Referanslar

1919 Bitişik veya Devam Eden Harita No’suBitişik veya Devam Eden Harita No’su

projeksiyon sistemleri

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