2. MAJ GEN(DR) B. NAGARAJAN ADDITIONAL SURVEYOR GENERAL INDIAN INSTITUTE OF SURVEYING & MAPPING SURVEY OF INDIA INDIAN GEODETIC DATUMS– HORIZONTAL AND VERTICAL

3.  INTRODUCTION  NEW MAPPING POLICY  VERTICAL DATUM  MAP PROJECTIONS  DISCUSSIONS

4. EARTH AS WE SEE FROM SPACE

5. ACTUAL SHAPE OF EARTH

6. Geoid Best Fitting Local ellipsoid and Geocentric Ellipsoid INDIA N N CG

7. P(X,Y,Z) ( ,,h) CG Geoid Geocentric & Locally Best Fitting Ellipsoids Yw Xw Zw Globally Fitting Ellipsoid Ye Ze Xe Locally Best Fitting Ellipsoid Translations -  x,  y,  z Rotations -  x,  y,  z Scale -  s

8. Representation of a point  Horizontal : Ellipsoid  Vertical : Geoid

9. Relationships between the earth's surface, the geoid and a reference ellipsoid

10. PRESENT COORDINATE SYSTEM IN USE

11. EVEREST ELLIPSOID Everest is a Locally best fitting ellipsoid. Everest is a Locally best fitting ellipsoid. In India the horizontal co-ordinates are computed on the Everest Spheroid. In India the horizontal co-ordinates are computed on the Everest Spheroid. Semi-major axis is having an error of 1 km. Semi-major axis is having an error of 1 km. Origin of the co-ordinates has been taken as Kalianpur. Origin of the co-ordinates has been taken as Kalianpur.

12. The system which is truly universal is satellite based, as Global Positioning System (GPS). The system which is truly universal is satellite based, as Global Positioning System (GPS). This is Geo-centric Ellipsoid. This is Geo-centric Ellipsoid. GLOBALLY ACCEPTED DATUM

13. Need of Switchover from EVEREST to WGS-84 Ellipsoid

14. Use of GPS becomes easier as its co-ordinates are referred to in WGS -84. Use of GPS becomes easier as its co-ordinates are referred to in WGS -84. Updation of maps using Satellite Imageries like that from IRS, IKONOS, Quick Bird etc. becomes easier as the satellite parameters are also referred to in geocentric reference frame. Updation of maps using Satellite Imageries like that from IRS, IKONOS, Quick Bird etc. becomes easier as the satellite parameters are also referred to in geocentric reference frame. Open Series maps being published by SOI are based on WGS-84 ellipsoid on UTM projection. Open Series maps being published by SOI are based on WGS-84 ellipsoid on UTM projection. Observations using satellite missions like Galileo, Glonass can also be made use of. Observations using satellite missions like Galileo, Glonass can also be made use of. All the guided missile systems, latest state-of-the- art weaponry are based on geocentric co-ordinate system, it becomes mandatory for us also to switch over to similar co-ordinate system. All the guided missile systems, latest state-of-the- art weaponry are based on geocentric co-ordinate system, it becomes mandatory for us also to switch over to similar co-ordinate system.

15. METHODS TO REALISE GEOCENTRIC CO-ORDINATES 1. Using Transformation Parameters 2. Redefining and Transforming Horizontal Datum 3. Re-observing in Entirely New co-ordinate System (ITRF)

16. Using Transformation Parameters Already available co-ordinates in Everest Spheroid can be transformed to WGS-84 by using transformation parameters, already determined. Already available co-ordinates in Everest Spheroid can be transformed to WGS-84 by using transformation parameters, already determined. These transformed co-ordinates will be suitable only for Mapping on small scale like 1:25,000 or 1: 50,000 scales. These transformed co-ordinates will be suitable only for Mapping on small scale like 1:25,000 or 1: 50,000 scales. Using this technique switching over to WGS- 84 co-ordinate system can be completed by mid of year 2007. Using this technique switching over to WGS- 84 co-ordinate system can be completed by mid of year 2007.

18. Redefining and transforming Horizontal Datum 2 D adjustment of the horizontal datum is already over. 2 D adjustment of the horizontal datum is already over. This data coupled with deflection of vertical and GPS data (WGS-84 co-ordinates) will be used for redefining horizontal datum. e.g., NAD-27 to NAD-83. This data coupled with deflection of vertical and GPS data (WGS-84 co-ordinates) will be used for redefining horizontal datum. e.g., NAD-27 to NAD-83. For this training of SOI personnel on software already available in any advance country will be required. For this training of SOI personnel on software already available in any advance country will be required. Time required to complete the job will by the end of year 2007. Time required to complete the job will by the end of year 2007.

19. Re-observing in entirely new system (WGS-84) For GCP Library, 300 stations with Primary Control will be available only by 2006. For GCP Library, 300 stations with Primary Control will be available only by 2006. The Primary Control will be densified further by establishing 2200 stations. The Primary Control will be densified further by establishing 2200 stations. This data will be adjusted and then made available for mapping purposes. This data will be adjusted and then made available for mapping purposes. Process is time consuming. Process is time consuming. This also depends on the availability of Funds. This also depends on the availability of Funds. Advantage of old available data will not be utilised. Advantage of old available data will not be utilised. Time required to complete the job will be next 8-10 years Time required to complete the job will be next 8-10 years

20. GCP LIBRARY DIEGO GARCIA LHASA ANKARA

21. Sl. No. NAME OF GEO-SPATIAL DATA CENTRE LOCAL ADDRESS OF THE CONCERNED GDC NO. OF GCP'S 1. ANDHRA PRADESH SURVEY OF INDIA, CST & MP campus, Uppal, HYDERABAD-500039 Fax: 040-27206064 & 27200359 E-mail : hyd2_dssecsoi@sancharnet.in hyd2_dssecsoi@sancharnet.in 22 2. ASSAM & NAGALAND SURVEY OF INDIA,GANESHGURI,CHARIALI GUWAHATI-781006 Fax-0361-2261725 E-mail : soi35p@gw1.dot.net.in soi35p@gw1.dot.net.in 10 3. BIHAR SURVEY OF INDIA,Ramnagar House,Anandpuri West,Boring Canal Road, PATNA-800001 Fax-0612-2271780 E-mail : soi75pty@dte.vsnl.net.in soi75pty@dte.vsnl.net.in 09 4. CHHATTISGARH SURVEY OF INDIA,Idgah Bhata,near water Tank,P.O. Sundernagar RAIPUR-492001 Fax-0771-2227250 E-mail : surveyin@bom6.bsnl.net.in surveyin@bom6.bsnl.net.in 09 5. GUJARAT,DAMAN & DIU SURVEY OF INDIA, Motor Bales & Service Building, Ashram Road, AHMEDABAD-380009 Fax-079-26576696 E-mail : no6partywc@hclinfinet.com no6partywc@hclinfinet.com 22 GCP LIBRARY ON WEBSITE OF GEODETIC & RESEARCH BRANCH http://www.gandrb.in

22. Kokrajhar Guwahati Chariduarr Golaghat Sibsagar Tinsukia Lumding Silchar Tuensang Kohima

23. TUENSANG LATITUDE: 26 ° 14' 06" LONGITUDE: 94 ° 47' 46" DESCRIPTION A brass punched on an iron angle fixed in a concrete pillar of 1ft. x 1ft. and 0.5 m above the ground level. The GCP pillar is situated inside the campus of 3 rd Battalion, Nagaland Armed Police, Tuensang, Kohima. It is situated at the south eastpart on top of a hillock and extremr southern end of the playground and 18 m west of the south east corner of the unit High School. It is best approachable from north side of the playground. The GCP pillar falls in the town of Tuensang,District Tuensang,Nagaland state. Ration,Transport, Medical,water and camping facilities are available near the GCP pillar. SKETCH

24. NEW MAPPING POLICY Open Series Maps Open Series Maps Defence Series Maps Defence Series Maps Switchover from Everest Co-ordinate System to Geocentric Co-ordinate System (ITRF). ITRF / GRS 80 ellipsoid. Switchover from Everest Co-ordinate System to Geocentric Co-ordinate System (ITRF). ITRF / GRS 80 ellipsoid. Survey of India took a conscious decision to go for Geocentric Reference Frame. Survey of India took a conscious decision to go for Geocentric Reference Frame.

25. OSM Series: OSM Series: Polyconic / Everest  UTM / WGS84 Polyconic / Everest  UTM / WGS84 DSM Series: DSM Series: Polyconic / Everest  LCC / WGS84 Polyconic / Everest  LCC / WGS84

26. OSM Series: OSM Series: Polyconic / Everest  UTM / WGS84 Polyconic / Everest  UTM / WGS84 DSM Series: DSM Series: Polyconic / Everest  LCC / WGS84 Polyconic / Everest  LCC / WGS84

27. VERTICAL DATUM

28. CHANDIPUR NIZAMPATNAM PONDICHERRY RAMESHWARAM KANNIYAKUMARI ANDROTH BEYPORE JAIGARH MAGDALLA VERAVAL AERIAL BAY CAMPBELL BAY EXISTING TIDE GAUGE STATIONS PROPOSED TIDE GAUGE STATIONS GARDEN REACH DIAMOND HARBOUR HALDIA SAGAR ENNORE EXISTING & PROPOSED

29. WAVE NEW GENERATION WATER LEVEL MEASUREMENT SYSTEM BENCH MARK TIDE POLE ZERO HEIGHT OF BENCH MARK ABOVE TIDEPOLE ZERO LOW WATER HIGH WATER MEAN SEA LEVEL HEIGHT OF BENCH MARK ABOVE MEAN SEA LEVEL

30. HEIGHT OF BED PLATE ABOVE ZERO OF TIDE GAUGE WAVE NEW GENERATION WATER LEVEL MEASUREMENT SYSTEM BENCH MARK HEIGHT OF BENCH MARK ABOVE TIDE GAUGE ZERO LOW WATER HIGH WATER MEAN SEA LEVEL HEIGHT OF BENCH MARK ABOVE MEAN SEA LEVEL BEDPLATE ZERO OF PRESSURE SENSOR PRESSURE SENSOR TIDE GAUGE FLOAT TYPE TIDE GAUGE STILLING WELL

31. OBSERVATIONS USING AUTOMATIC TIDE GAUGES

32. Data Extraction MEAN SEA LEVEL 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 0.0 m 1.0 m 2.0 m 3.0 m 4.0 m TIME (Hour) HEIGHT CHART DATUM

33. N + H = h N – IS THE GEOIDAL SEPARATION WHICH VARIES H – IS ORTHOMETRIC HEIGHT h – IS THE ELLIPSOID ELEVATION To Convert h to H you need N. The Accuracy of Elevations Depend on how well you know N. EARTH SURFACE GEOID ELLIPSOID h H H h N N

34. GEOID UNDULATION MAP OF INDIA  GEOID UNDULATION COMPUTED USING OSU 91A MODEL USING ONLY UPTO DEGREE 100 COEFFICIENTS  UNDULATIONS REFER TO GRS 80 REFERENCE ELLIPSOID

35. MSL H1 H2 h1 h2 h2 > h1 H1 > H2 A B MSL & Ellipsoidal Heights ELLIPSOID Heights by Satellite Altimeter is Ellipsoidal Height

36. Projection Transformation of Three Dimensional Space onto a two dimensional map Transformation of Three Dimensional Space onto a two dimensional map A systematic arrangement of intersecting lines on a plane that represent and have a one to one correspondence to the meridians and parallels on the datum surface A systematic arrangement of intersecting lines on a plane that represent and have a one to one correspondence to the meridians and parallels on the datum surface

37. Classification A) Based on Extrinsic property A) Based on Extrinsic property Nature: Nature: Plane, Cone, CylinderPlane, Cone, Cylinder Coincidence: Coincidence: Tangent, Secant, PolysuperficialTangent, Secant, Polysuperficial Position: Position: Normal, Transverse, ObliqueNormal, Transverse, Oblique

38. B) Based on Intrinsic Property B) Based on Intrinsic Property Property of Projection: Property of Projection: EquidistantEquidistant Conformal or OrthomorphicConformal or Orthomorphic Equivalent or Equal areaEquivalent or Equal area Generation: Generation: Geometric, Semi Geometric, MathematicalGeometric, Semi Geometric, Mathematical Classification contd.

39. Azimuthal Projections

40. Cylindrical Projections Tangent Oblique Transverse Secant

41. Conic Projections

42. Cylindrical Map Projections Cylindrical map projections are made by projecting from the globe onto the surface of an enclosing cylinder, and then unwrapping the cylinder to make a flat surface Cylindrical map projections are made by projecting from the globe onto the surface of an enclosing cylinder, and then unwrapping the cylinder to make a flat surface MercatorMercator Transverse MercatorTransverse Mercator Cassini-SoldnerCassini-Soldner

43. Mercator Projection Cylindrical, Conformal Cylindrical, Conformal Meridians are equally spaced straight lines Meridians are equally spaced straight lines Parallels are unequally spaced straight lines Parallels are unequally spaced straight lines Scale is true along the equator Scale is true along the equator Great distortion of area in polar region Great distortion of area in polar region Used for navigation Used for navigation

44. REGULAR CYLINDRICAL PROJECTION: THE MERCATOR

45. Transverse Mercator Projection Cylindrical (Transverse) Cylindrical (Transverse) Conformal Conformal Central meridian and equator are straight lines Central meridian and equator are straight lines Other meridians and parallels are complex curves Other meridians and parallels are complex curves Used extensively for quadrangle maps at scales from 1:24,000 to 1:250,000 Used extensively for quadrangle maps at scales from 1:24,000 to 1:250,000 For areas with larger north-south extent than east-west extent For areas with larger north-south extent than east-west extent

46. TRANSVERSE CYLINDRICAL PROJECTION: THE TRANSVERSE MERCATOR

47. Cassini- Soldener Projection Cylindrical, Tangent, Transverse Cylindrical, Tangent, Transverse Equidistant Equidistant Cylinder is tangent along the meridian centrally located Cylinder is tangent along the meridian centrally located Scale deteriorates away from central meridian Scale deteriorates away from central meridian Normally used in 70 km belt from the central meridian, as linear distortion factor at 70 km is 1.00006 Normally used in 70 km belt from the central meridian, as linear distortion factor at 70 km is 1.00006 Used for old cadastral surveys in India. Used for old cadastral surveys in India.

48. CASSINI-SOLDENER PROJECTION

49. Conic Projections For a conic projection, the projection surface is cone shaped For a conic projection, the projection surface is cone shaped Locations are projected onto the surface of the cone which is then unwrapped and laid flat Locations are projected onto the surface of the cone which is then unwrapped and laid flat

50. LCC PROJECTION

51. Lambert Conformal Conic Projection Conical, Conformal Conical, Conformal Parallels are concentric arcs Parallels are concentric arcs Meridians are straight lines cutting parallels at right angles. Meridians are straight lines cutting parallels at right angles. Scale is true along two standard parallels, normally, or along just one. Scale is true along two standard parallels, normally, or along just one. It projects a great circle as a straight line – much better than Mercator It projects a great circle as a straight line – much better than Mercator Used for maps of countries and regions with predominant east west expanse Used for maps of countries and regions with predominant east west expanse Used for plane coordinate system (SPCS) in USA Used for plane coordinate system (SPCS) in USA

52. LCC PROJECTION

53. Three partial equidistant conic maps, each based on a different standard parallel, therefore wrapped on a different tangent cone (shown on the right with a quarter removed plus tangency parallels). When the number of cones increases to infinity, each strip infinitesimally narrow, the result is a continuous polyconic projection

54. Polyconic Projection In this projection all parallels are projected without any distortion In this projection all parallels are projected without any distortion Scale is exact along each parallel and central meridian. Scale is exact along each parallel and central meridian. Parallels are arcs of circles but are not concentric. Parallels are arcs of circles but are not concentric. It is neither conformal nor equal area. It is neither conformal nor equal area.

55. Central meridian and equator are straight lines; all other meridians are curves. Central meridian and equator are straight lines; all other meridians are curves. Central Meridian cuts all parallels at 90 degrees Central Meridian cuts all parallels at 90 degrees Free of distortion only along the central meridian. Free of distortion only along the central meridian. It has rolling fit with adjacent sheets in EW direction. It has rolling fit with adjacent sheets in EW direction. Used in India for all topographical mapping on 1:250,000 and larger scales. Used in India for all topographical mapping on 1:250,000 and larger scales. Polyconic Projection contd.

56. Azimuthal Projections For an azimuthal, or planar projection, locations are projected forward onto a flat plane. For an azimuthal, or planar projection, locations are projected forward onto a flat plane. The normal aspect for these projections is the North or South Pole. The normal aspect for these projections is the North or South Pole.

57. Scale Error = True Distance – Grid Distance Scale Error = True Distance – Grid Distance Grid Distance = True Distance * Scale Factor Grid Distance = True Distance * Scale Factor Scale Error for Lambert Grid = 1 / 824 Scale Error for Lambert Grid = 1 / 824 Scale Factor = 1 – 1 / 824 = 823 / 824 = 0.99878 Scale Factor = 1 – 1 / 824 = 823 / 824 = 0.99878

58. False Northing and False Easting Calculating coordinates is easier if negative number aren’t involved. Calculating coordinates is easier if negative number aren’t involved. State Plane and Universal transverse Mercator coordinates State Plane and Universal transverse Mercator coordinates Expressed in coordinate units, not degrees. Expressed in coordinate units, not degrees.

59. SPECIFYING AN ORIGIN SHIFT: THE FALSE EASTING AND FALSE NORTHING

60. Universal Transverse Mercator Particular case of Transverse Mercator Projection. Particular case of Transverse Mercator Projection. The earth between latitudes 84  N and 80  S, is divided into 60, 6  wide; The earth between latitudes 84  N and 80  S, is divided into 60, 6  wide; Latitude origin – the equator Latitude origin – the equator Assumed (false) northing (y): 0 metres for northern hemisphere; 10,000,000 metres for southern hemisphere Assumed (false) northing (y): 0 metres for northern hemisphere; 10,000,000 metres for southern hemisphere Assumed (false) easting (x): 500,000 metres; scale factor at the central meridian: 0.9996 Assumed (false) easting (x): 500,000 metres; scale factor at the central meridian: 0.9996

62. Universal Polar Stereographic (UPS) Defined above 84 degrees north latitude and 80 degree south Defined above 84 degrees north latitude and 80 degree south Conformal Conformal Meridians are straight lines Meridians are straight lines Parallels are circles Parallels are circles Scale increases from center point Scale increases from center point Used in conformal mapping of polar regions Used in conformal mapping of polar regions

64. State Plane Coordinates Lambert Conformal Conic Projections are used for rectangular zones with a larger east-west than north south extent. Lambert Conformal Conic Projections are used for rectangular zones with a larger east-west than north south extent. Transverse Mercator projections are used to define zones with a larger north-south extent. Transverse Mercator projections are used to define zones with a larger north-south extent. One State Plane zone in Alaska uses an oblique Mercator projection. One State Plane zone in Alaska uses an oblique Mercator projection.

65. Projection Parameters To define the coordinate system completely, it is not sufficient simply to name the kind of projection used, it is also necessary to specify the projection parameters. To define the coordinate system completely, it is not sufficient simply to name the kind of projection used, it is also necessary to specify the projection parameters. The set of parameters required depends on the kind of projection. The set of parameters required depends on the kind of projection. The central meridian of the projection for cylindrical, where it touches the ellipsoid surface. The central meridian of the projection for cylindrical, where it touches the ellipsoid surface.

66. Projection Parameterscontd. The standard parallel(s) for conic projections. The standard parallel(s) for conic projections. The false easting and false northing The false easting and false northing The units The units Reference ellipsoid Reference ellipsoid

67. Choosing a map Projection The choice of map projection is made to give the most accurate possible representation of the geographic information, given that some distortion is inevitable. The choice depends on: The choice of map projection is made to give the most accurate possible representation of the geographic information, given that some distortion is inevitable. The choice depends on: The location The location Shape Shape Size of the region to be mapped Size of the region to be mapped The theme or purpose of the map The theme or purpose of the map

68. MODERNISATION OF INDIAN TIDE-GAUGE NETWORK

69. INDIAN TIDE-GAUGE NETWORK

70. GPS receivers are being deployed to segregate the sea level rise from that of possible subsidence or upheaval of the land mass. GPS receivers are being deployed to segregate the sea level rise from that of possible subsidence or upheaval of the land mass. Both tidal and GPS data are being transmitted in real time from the remote locations and received through dedicated VSAT network, at the central hub installed at National Tidal Data Centre (NTDC) / National GPS Data Centre located at Geodetic & Research Branch, Survey of India, Dehra Dun. Both tidal and GPS data are being transmitted in real time from the remote locations and received through dedicated VSAT network, at the central hub installed at National Tidal Data Centre (NTDC) / National GPS Data Centre located at Geodetic & Research Branch, Survey of India, Dehra Dun.

71. A 5.2 m VSAT antenna has been installed at National Tidal Data Centre, Dehradun to receive tidal and GPS data on real time. Tide gauge stations has been provided with 2.4 m VSAT antennas for transmission of this data. Redundant power supply through UPS has also been arranged.

72. GPS data is being encrypted at remote locations (Tidal Observatories) and decrypted at central hub. GPS data is being encrypted at remote locations (Tidal Observatories) and decrypted at central hub. Tidal and GPS data are being analysed in the real time to identify any possible signatures related to the tsunami and storm surge. Tidal and GPS data are being analysed in the real time to identify any possible signatures related to the tsunami and storm surge.

73. DISASTER CONTROL STATION TSUNAMI WARNING GPS ANTENNA SOLAR PANEL SATELLITE NATIONAL TIDAL DATA CENTRE VSAT ANTENNA JETTY NATIONAL GPS DATA CENTRE TIDE GAUGE GPS RECEIVER REAL TIME DATA TRANSMISSION FROM TIDE GAUGE STATION VSAT ANTENNA TIDE GAUGE STATION STILLING WELL

74. (1) Paradip (2) Visakhapatnam (3) Tuticorin (4) Cochin (5) Port Blair (6) Kandla (7) Ennore (8) Marmagao (9) Kavaratti (10) Haldia (11) Machilipatnam (12) Chennai (13) Nancowry (14) Minicoy Phase – I (Completed) Phase – II (Completed) (1)Vadinar (2)Okha (3)Porbandar (4)Veraval (5)JNPT (6)Karwar (7)New Mangalore (8)Campbell Bay (9)Aerial Bay (10)Hugli Point Phase – III (1) Garden Reach (2) Nagapattinam (3) Krishnapatnam (4) Kakinada (5) Androth (6) Gopalpur (7) Cuddalore (8) Kanyakumari (9) Rameshwaram (10) Beypore (11) Jaigarh (12)Sagar

75. Sl. No. PORT NAME VSATPTGGPSCTGNIOT-PTG1Marmagao 2Visakhapatnam 3 Paradip Paradip 4 Cochin Cochin 5 Port Blair  6Kandla 7Ennore 8 Kavaratti Kavaratti 9Tuticorin 10Haldia 11Machilipatnam 12Chennai 13Nancowry 14Minicoy 15Okha 16Porbander 17Veraval 18Karwar 19 New Mangalore  20JNPT 21Vadinar 22 Campbell Bay 

76. DISCUSSIONS

77. Email ID: ngeoid@Yahoo.com