Concept of projection and its Applicability

1. Need For Different
Projections -Concept and
It’s Applicability
ASSIGNMENT PRESENTATION
By
SUPARNA DEY
MT/RS/10003/16
PRINCIPLE OF REMOTE SENSING
TRS1001

2. OVERVIEW
 Introduction
 History
 Need For Different Projections
 Some Terminology Used In Projection System
 Different Types of Projection System
 Applicability
 References

3. The term projection means the presentation of image on screen.
A map projection means the representation of latitude and longitude of the
globe on a flat sheet/paper.
As simply derive that 3D feature convert in to 2D form .
INTRODUCTION
Ellipsoid for different country

4. Milet made the first map in some projection.
600 B.C:It was a map of the heavenly sphere in gnomonic projection.
150 B.C :Stereographic and orthographic projections .
the first projection of the spherical world, onto a plane. PTOLEMY'S
PROJECTION in 1477.
16th
and 17th
centuries publication of geographic atlases was carried out
by the famous Dutch cartographers Ortelius and Mercator:Mercator was
the first whoever applied conformal cylindrical projection.
19th century to the theory of map projections was the establishment of
firm mathematical principals. New projections by Mollveide, Albers, Gall
etc.
Arthur H. Robinson invented this projection(Orthophanic projection).

5. Need For Different Projections
We have different projections because the earth is a sphere, and the map is flat.
The projections are based on measurements along "cuts" or "stretch points" on
the planet at specific spots to allow the sphere to be shown in a flat medium.
Measurement will be easy and accurate

6. PROJECTION PARAMETERS:
Coordinate system: A coordinate system is a reference system to Measure
the point:2d or 3d.
Latitude : the angle north or south
from the equatorial plane .
Longitude: the angle east or west from
an identified meridian.
Parallels : lines on the surface of
the sphere parallel to the equator.
These are lines of equal latitude.
Meridians : lines on the surface of
the sphere running from pole to
pole. These are lines of equal
longitude.
•A lattice of parallels and meridians is known
as a graticules.

7. Datum-Geoid-Ellipsoid
A 3D model of Earth surface: Spheroid
Shape of the earth:Ellipsoid
The model to convert 3D points to 2D surface with
minimal distortion:Projection.
The 3D model is related to shape of the earth: Datum
Vertical Datum : These are the reference
value for a system to measure elevation.
Horizontal Datum: These are the
reference value for a system to measure
location on a earth.
Geoid: It is a model of global mean sea level
that is used to measure precise surface
elevations.
In other things, Geoid is related to Isostasy. The
term means that the Earth’s topographic mass is
balanced (mass conservation) in one way or
another, so that at a certain depth the pressure is
hydrostatic.

8. DIFFERENT TYPES OF PROJECTION SYSTEMS
Preserving direction (Azimuthal Or Zenithal)
Preserving shape locally (Conformal Or
Orthomorphic)
Preserving area (Equal-area Or Equiareal Or
Equivalent Or Authalic)
Preserving distance (equidistant), a trait possible
only between one or two points and every other
point
Preserving shortest route, a trait preserved only
by the Gnomonic Projection.
Mostly used for East-west(Low altitude)
land Areas.
Mostly used for North-south(Middle altitude ) Areas. This is used forPolar Region good for
global views.

9. CYLINDRICAL PROJECTIONS
Regular Cylindrical : Transverse Cylindrical Oblique Cylindrical
Mercator projection
Universal Tranverse Mercator
(UTM) projection
Lambert's cylindrical equal-area
projection

10. CONICAL PROJECTIONS
Regular Conical:
Equidistant conical
Albers conical
Lambert conformal conic
al
Pseudo-conical projection
Polyconic projection
•Mostly used for East-west(Low
altitude) land Areas.

11. AZIMUTHAL PROJECTION
Polar Azimuthal (plane)
latitude and longitude
origin is at the pole.
Oblique Azimuthal (plane)
centered at a latitude and
longitude origin other than
the pole
Gnomonic projection:
1.displays great circles as
straight lines.
2. be constructed by using a
point of perspective at the
center of the Earth.
Orthographic projection:
1.each point on the earth to
the closest point on the plane.
2. constructed from a point of
perspective an infinite
distance from the tangent
point.
3. It Can display up to a
hemisphere on a finite circle.
Azimuthal conformal projection :
1.known as the
stereographic projection.
2. can be constructed by using the
tangent point's antipode as the
point of perspective.
3.It Can display nearly the entire
sphere's surface on a finite circle.
Azimuthal equidistant projectio
Lambert azimuthal equal-area
projection:
Logarithmic azimuthal
projection:

12. APPLICABILITY
Maps that Preserve Shape: Conformal Projection
Topographic Maps And Cadastral (Land Parcel)
Navigation Charts (For Plotting Course Bearings And Wind Direction)
Civil Engineering Maps
Military Maps
Weather Maps
Maps that Preserve Area : Equal-area Projection
The density of an attribute with dots (for example, population density)used
By National Geographic Atlas.
Maps that preserve scale: Azimuthal Equidistant projection
Seismic maps showing distances from the epicenter of an earthquake.
Maps used to calculate costs or charges based on straight-line distance
from a source.
Maps used to calculate ranges; for example, the cruising ranges of airplanes
or the habitats of animal species.
Maps that preserve direction: Azimuthal Projection
Gnomonic projections are useful for planning air and sea routes and for mapping
phenomena, like radio waves, that follow shortest-distance.

13. Region Suitable projection specification
Whole Earth
Robinson (pseudocylindrical) or Miller Cylindrical 1.Robinson seems to be fashionable for thematic
maps.
2.Any of the pseudocylindrical projections will be
fine if you like their appearance better.
Hemispheres
Orthographic (azimuthal) for a "view from space" look,
and Lambert Azimuthal Equal Area
For thematic maps where the relative size of
countries near the edge of the projection is to be
preserved
Continents
Lambert Conformal Conic Projection For North America and Eurasia.
Lambert Azimuthal Equal Area or Orthographic Projection for South America and Africa.
Orthographic Projection
for Australia, and Antarctica
E-W Countries or
Regions
Lambert Conformal Conic Projection for US, Canada, Russia, and China.
Lambert Conformal Conic or Orthographic Projection for Europe
Orthographic or Lambert Azimuthal Equal Area Projection For otherwise.
Polar Regions
Orthographic or Lambert Azimuthal Equal Area Projection 1.The National Atlas of the US uses to display
information in the online Map Maker application .
2. European Environment Agency uses for
European mapping for statistical analysis and
display.
3. Used in scientific disciplines such as geologyor
plotting the orientations of lines in three-
dimensional space
Oceans
Orthographic or Lambert Azimuthal Equal Area Projection
Smaller Countries or
Regions
Orthographic Projection All the projection lines are orthogonalto the
projection plane
N-S Countries, Oblique
Regions
Transverse Mercator Projection Long, thin countries aligned North-South such as
Chile
Oblique Mercator Projection Oblique regions like the Alaska panhandle are
Regions With Suitable Projection

14. REFERENCES:
Pijushkanti Saha, Partha Basu: Advanced Practical Geography
Jonathan Iliffe Roger Lott:Datum and map projection
Slocum, Terry A.; Robert B. McMaster; Fritz C. Kessler; Hugh H. Howard (2005). Thematic Car
ISBN 0-13-035123-7. pubs.er.usgs.gov/publication/70047422
Miller, Osborn Maitland (1942). "Notes on Cylindrical World Map Projections". Geographical
Review. 43 (3): 405–409.
www.wikipedia.com
Snyder, J.P. (1989).Album of Map Projections, United States Geological Survey Professional
Paper. United States Government Printing Office. 1453.