This document discusses key concepts in GIS including maps, coordinate systems, map projections, and their application in Nepal. It defines analog and digital maps, and explains that the earth is an ellipsoid rather than a perfect sphere. It introduces geographic and rectangular coordinate systems, and defines map projections as methods to represent the curved earth on a flat surface. The document outlines the Everest ellipsoid and UTM/MUTM projection systems used in Nepal.

1. MAPS ,COORDINATE SYSTEM AND MAP PROJECTION
Day 1 –GIS Training IOE, Pulchowk
Presented By:
Uttam Pudasaini
Geomatics Engineer
NAXA Pvt. Ltd.

2. Presentation Outline
 Basic Concepts:
Maps
 Types of Maps: Analog and Digital
Earth and its Shape: Geoids and Ellipsoids
Coordinate System: Geographical and
Rectangular
Map Projection
Coordinate System in Nepal
Installation of
Arc GIS Version 10.0

3. MAPS
 A graphical representation of ground reality
 Objects on the ground are reduced to a certain scale and represented
on map
Maps: Not a reality in itself

4. Analog Vs Digital MAPS
Analog Maps
 Rigid form of map where message is
conveyed by virtue of symbology.
 Measurable but not interactive.
 They are always projected.
 Difficult to integrate with other data.
Digital Maps
 Maps in a digital media.
 Interactive options according to
map’ objective.
 Maps can be in both 2D and 3D
format.
 Easy integration with other data.

5. EARTH And its Shape (Misconceptions)
Earth surface is a plane surface.
If we are going to sail further, we are going to
fall down one day. Rectangular Earth

6.  Earth is in fact flattened slightly at the poles and bulges somewhat at the
equator.
 Mathematical Shape of the earth : An Ellipsoid, A geometrical figure which
would be obtained by rotating an ellipse about its shorter axis.

7. Coordinate System

8. Geographical Coordinate System
 Uses latitude and longitude to
represent the x,y position in
space.
 Useful for locating positions on
the curved surface of the
earth.
Rectangular Coordinate System
 Uses x,y coordinates to
represent positions on a
plane.
 The location of any point in
this system is defined by a set
of two values, p (x, y).
Contd…

9. Map Projection
 Earth surface in reality is a curved surface with no perfect geometrical
shape.
 Mapping in a globe is an easy way to map the earth.
 Measurement as well as sharing of data and details is always difficult if a
map is represented on globe.
Projection: A method by which the curved surface of the earth is represented
on a flat surface.

10. Contd..
Includes two operations:
 Alteration of Scale.
 Transformation to
Plane surface.

11. Numerous projections have been invented, and
arguments continue about which is best for which
purposes.

12. World Geodetic System - 1984 (WGS 84)
 A three dimensional Right handed
Cartesian coordinate system followed
around the globe.
Origin = Earth’s centre of mass
Z-Axis = Direction of the Conventional Terrestrial Pole
X-Axis = Intersection of the WGS 84 reference meridian plane and the
plane of the CTP’s equator.
Y-Axis = Measured in the plane of the CTP equator, 90° East of the x-axis.

13. Coordinate System in Nepal

14. Everest Ellipsoid:
Reference Ellipsoid being adopted by Nepal
 Semi major Axis ,a = 6377276.345 m
 Semi minor Axis ,b= 6356075.413
 Flattening  
1/ 300.8017
a 
b

a
f

15. Universal Transverse Mercator (UTM) Projection
 Introduced by US Army Map Service in the 1957.
 Most common system of projection used for large scale mapping
around the world.
 Based on a Transverse Cylindrical projection.
 Cylinder touches the reference globe along a chosen meridian.

16.  Consists of 60 zones. Each zone has a width of 60 of longitude.
 Zones are numbered sequentially from west to east, starting with 1. Zone
1= 1800W to 1740W, with CM 177 W.

17. MUTM Projection System
Consists of 120 zones ,each of width 30 longitude
Unit of measurement is meter.
 Scale factor at the central meridian = 0.9999.
 False Easting at Central Meridian =500000 m.
 False northing at the Equator is 0 m.
False Easting and False Northing:
 Arbitrary large values are assigned to
Y-axis origin and X-axis origin so
called false easting and false
northing respectively.
 Overcomes the inconveniences
caused by the negative numbers in
Rectangular Coordinate System.

18. Conclusion

19. Reading Materials
 Latitudes and Longitudes:
 https://www.youtube.com/watch?v=y6aPerEPbvw
 Coordinate System and Projections:
 https://www.youtube.com/watch?v=HifUBn4APZA