REDEFINING THE HORIZONTAL & VERTICAL CONTROL IN INDIA, GCPs, DATUM TRANSFORMATION, UPDATION OF LAND RECORDS : CONTRIBUTIONS OF SURVEY OF INDIA U. N. Mishra Director Geodetic & Research Branch

Activities of Geodetic & Research Branch Responsible to Provide Horizontal and Vertical Control Determination of Transformation Parameters – between WGS WGS--84 and Everest Everest.. These are available with G&RB GCP Library Project – About to complete Antarctica Expedition – Participation since 1990 1990--91 National GPS Data Centre –Analysis of GPS data received from Permanent Stations in India Real Time GPS Data Centre – Receiving GPS data from Tidal Ports in India Redefinition of Indian Vertical Datum

Activities of Geodetic & Research Branch Contd. Geodetic & Geophysical studies--Gravity, studies Geomagnetism Astronomical Observations Observations--Determination of True North Collection, processing and archiving of Tidal Data along the Indian coast coast.. Publication of Indian Tide table and Hugli river tide tables every year in advance advance.. Redefinition of Indian Vertical Datum Data dissemination Capacity building/Training

Requirement of Datum and Coordinate System

To perform surveying and Mapping a datum and coordinate system is required required..

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What is Datum? A datum (plural datums datums)) is a reference from which measurements are made made.. It is an associated model of the shape of the earth (ellipsoid) to define a Geographic Coordinates Coordinates.. Horizontal datums are used for describing a point on the earth’s surface, in latitude and longitude or another coordinate system.. system Vertical datums measure elevations or depths depths..

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Datum used in Surveying: Horizontal Datum Datum-- (Ellipsoid) Vertical datums – (Geoid Geoid/MSL) /MSL)

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Geoid Figure of Earth Geoid (Close to MSL)

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Actual shape of earth

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The Ellipsoid The Geoid is a complicated surface defined by infinite number of observed gravity points, hence not suitable to perform mathematical computations computations.. The ellipsoidal surface is smooth and convenient for mathematical operations operations.. Therefore ellipsoid is widely used as the reference surface (datum) for horizontal coordinates in geodetic network network..

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Ellipsoid (Best Fit Mathematical Surface) Figure of Earth

Ellipsoid (GRS80)

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Horizontal Datum: An Ellipsoid is Used as Horizontal Datum Datum.. Its centre coincides with the centre mass of the earth.. earth Its minor axis is parallel to the axis of rotation of the earth earth.. Everest ellipsoid was used as a Horizontal datum in India and adjacent countries

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Everest Ellipsoid Evolved from measurement of great Meridonial arc from Kanyakumari to Banog near Mussoorie Mussoorie.. Arc closely passes through 780 E Meridian Meridian.. Col. Lambton started the observation of Great Arc on 10 April Col. 1802 from St St.. Thomas Mount, Madras by measuring a base line of 40006 40006..4 feet (12194 12194m) m).. Sir George Everest in 1830 concluded the task of Great Arc measurement by computing the parameters of the Ellipsoid which was named after him him.. The values are as under a = 6377301 6377301..243 243m m b = 6356100 6356100..231 231m m f = 1/300 300..8017

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World Geodetic System 1984 (WGS(WGS-84) For all practical purposes, the GRS GRS80 80 and WGS WGS84 84 ellipsoids are identical identical.. WGS84 was designed to be a practical standard global, WGS84 geocentric horizontal datum for for:: Mapping Charting Geodesy and Navigation 2/15/2012

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WGS84 Ellipsoid Bureau International de l’Heure (BIH)

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Best Fit Ellipsoid and Geocentric Ellipsoid

Figure of Earth Geoid (Close to MSL) Locally Best Best--fit Ellipsoid (Everest Ellipsoid)

Centre of Mass of Earth

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Geocentric Ellipsoid (GRS80)

International Terrestrial Reference Frame (ITRF) (ITRF) In the Surveying terminology, a reference frame is a set of points with their coordinates which realize an ideal reference system The International Earth Rotation Service (IERS) mission is to provide internationally accepted terrestrial reference systems ITRF is produced by IERS The ITRF is realized through the global Cartesian coordinates and linear velocities of a global set of sites equipped with various space geodetic observing systems systems.. The space geodetic techniques used at present are LLR, SLR, VLBI, GPS, and DORIS (Doppler Orbitography and Radio Radio-positioning Integrated by Satellite, is a French precision navigation system) 17 2/15/2012

IGS The International GNSS Service (IGS) is a voluntary federation of many worldwide agencies IGS collects, archives, and distributes GPS observation data sets of sufficient accuracy to satisfy the objectives of a wide range of applications and experimentation experimentation.. IGS has a number of components components:: an international network of over 500 continuously operating dual dual-frequency GNSS stations More than a dozen regional and operational data centers three global data centers seven analysis centers and a number of associate or regional analysis centers 2/15/2012

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IGS Stations

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Status of Horizontal Control in India - Past Old Geodetic Triangulation GT Triangulation was started on 10th April, 1802 with an aim to design a Horizontal datum for India and adjacent countries Observation – Theodolite for angular and Invar wire for linear measurements Layout – Geometrical figure adjustment can be performed

and

network

so

that

Result – Everest Ellipsoid as Indian Geodetic Datum, Horizontal coordinates for surveying and mapping activities In all 2873 GT stations in India situated on high hill tops tops.. Present status – Switch over from Everest to WGS WGS--84

Status of Horizontal Control in India - Past

Status of Horizontal Control in India - Past Number of Series of Indian Triangulation – 37 Primary and 57 Secondary Secondary.. One Series is adjusted within it but most of the series are not adjusted among themselves resulting in mismatch at junctions junctions.. Accuracy achieved is inferior compared to accuracy achieved through GPS technology technology..

Status of Horizontal Control in India - Present GCP Library Phase - I The Phase Phase--I consists of about 300 points spacing about 250 to 300 km apart These points will serve as the framework for geodetic control for entire country country.. These points has permanent monumentation monumentation.. GPS observations have already been completed using Dual frequency GPS receivers on all these stations in static relative mode w.r.t. IGS Stations (International GPS Stations for Geodynamics Studies) Studies)..

GCP Library Phase – I Monument

Design of GCP Library Phase-I Monument

GCP Library Phase-I: Distribution in India 1

Andhra Pradesh

21

2

Assam & Nagaland

11

3

Bihar

9

4

Chhattisgarh

8

5

Delhi

1

6

Gujarat, Daman & Diu

22

7

Haryana

6

8

Himanchal Pradesh

7

9

Jammu & Kashmir

10

10

Jharkhand

8

11

Karnataka

21

12

Kerala & Lakshyadeep

6

13

Madhya Pradesh

18

14

Maharashtra & Goa

24

15

Meghalaya & Arunachal Pradesh

6

16

Orissa

11

17

Punjab & Chandigarh

7

18

Rajasthan

25

19

Tamilnadu, Pondi, A&N Islands

16

20

Tripura, Manipur & Mizoram

6

21

Uttar Pradesh

22

22

Uttarakhand

15

23

West Bengal & Sikkim

11

Total

291

Achievements: GCP PhasePhase-I Phase--I: Phase Observations on 291 stations in different states is completed Coordinates of all points has been computed using Bernes 5.0 software with reference to IGS stations in ITRF 2008 (Epoch 2005 2005))

Subsequent Phases Of GCP Library Phase--II Phase The control is being densified by providing 2200 points at the spacing of 25 to 30 km This task is under progress and following states have already been covered HP, Haryana, Punjab MP, UP, Bihar (North) Maharastra, Gujrat Karnataka, Kerala, Tamilnadu Andhra Pradesh, Orissa, WB Uttarakhand Rajasthan: GPS Observation is in Progress

Phase--III Phase Control will be further densified by regional directorates of Survey of India at the spacing of 8 to 10 km (about 7000 points)

Subsequent Phases Of GCP Library Phase--II Phase States where observations has to be done in next a few months Chattisgarh,, South Bihar, Jharkhand (Naxalite Belt area) Chattisgarh J & K State North Eastern States including Sikkim Sikkim..

Achievements: GCP PhasePhase-II Phase--II Phase

Observations has been completed in the following states Name Of State Punjab, Haryana, Himachal MP, UP, Bihar Maharastra, Gujrat Karnataka, Kerala, Tamilnadu AP, Orissa, WB W UP and Uttarakhand

Rajasthan (work in progress) Total GCP Observed

No. of Phase II GCP Observe (31+35+22) = 88 (178+84+50) = 312 (219+145) = 364 (132+45+106) = 283 (244+95+67)= 406 86

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Achievements: GCP PhasePhase-II

Work in Progress

Field work will start in June / July 2012

Field work will start in 3rd week of Feb 2012

Network Adjustment Strategy Coordinates of CORS will be computed with reference to ITRF 2008 (Epoch (Epoch2005 2005)) coordinates of IGS Stations Stations.. Here epoch referes to the co co--ordinates of IGS station on 1st January, 2005 2005.. We are adjusting the co co--ordinates of 1st phase points with reference to Permanent Continuous Operating Reference Stations (CORS) (CORS).. As we know that the Indian plate is moving like other plates of earth due to plate tectonic tectonic.. It is also seen that Indian plate is having appreciable velocity of the order of 5-6 cm par annum annum.. If we adjust our Ist Phase points with respect to our permanent CORS better adjustment will result under appreciable velocity of Indian plate plate.. CORS

IGS (HYDE)

Phase-I

IGS (IISC)

Phase-I

CORS

Phase-I Phase-I

Contd… Contd …

Owing to velocity factor due to movement of Indian plates the co co--ordinates of a point will be different in different years but all the co co--ordinates are standardised at epoch 2005 in ITRF 2008 reference frame.. frame So, co co--ordinates may be revised after 10 – 15 years to different ITRF epoch epoch.. User agency should adopt the co co--ordinates supplied by SOI only for consistency consistency..

GCP PhasePhase-I Network: Adjusted with reference to CORS • At present the network is being adjusted using the vendor software. • However, after completion of entire work of Phase-II also, network is proposed to be adjusted using BIGADJUST programme as a measure of independent check.

GCP PhasePhase-II Network: Adjusted with reference to Phase--I Phase

Accuracy Expected Positional accuracy of control points after final adjustment is expected to be better than 3cm for Phase Phase--I GCPs 9cm for phase phase--II GCPs and 15 cm cm for phase phase--III GCPs

Accuracy Expected Positional accuracy of control points after final adjustment is expected to be better than 3cm for Phase Phase--I GCPs 9cm for phase phase--II GCPs and 15 cm cm for phase phase--III GCPs

National GPS Data Centre National GPS Data Centre was setup under Satellite Geodesy Wing in March 2001 for deformation and plate motion studies It has the mandate of receiving, analyzing and archiving of Permanent GPS stations data across the country The data is being received and archived from Permanent GPS stations This data is available for sharing with other scientific organizations for scientific studies studies..

PANAMIC LEH JAMMU & KASHMIR HENLE

INDIAN GPS NETWORK

NADDI KOTHI HIMACHAL PRADESH

BHATWAR I

NATIONAL GPS DATA CENTRES,DEHRADUN

PUNJAB UTTARAKHAND

MUNSIYARI ALMORAI PITHORAGARH

DEHRADUN HARYANA DELHI

GANGTOK LUCKNOW KANPUR

BOMDILA SIKKIM TEJPUR

RAJASTHAN

UTTAR PRADESH

GUAHATI

MUKUKCHUNG SHILLONG

MEGHALAYA

BIHAR

IMPHAL

BANGLADESH DHANBAD JHARKHAND

KANDLA

MADHYA PRADESH

WEST BENGAL

VADINAR OKHA

GARDEN REACH

BHOPAL

GUJARAT

JABALPUR DIAMOND HARBOUR

PORBANDAR HALDIA VERAVAL

SAGAR

ORISSA BHUBANESHWAR PARADIP MAHARASHTRA

GOPALPUR

MUMBAI PUNE JNPT ANDHRA PRADESH

JAIGARH

ARABIAN SEA

VISAKHAPATNAM KAKINADA

MACHILIPATNAM

HYDERABAD

MARMAGAO

GOA

KARWAR

BAY OF BENGAL

KARNATAKA KRISHNAPATNAM AERIAL BAY ENNORE

NEW MANGALORE

CHENNAI BANGALORE

BEYPORE

PONDICHERY

PORT BLAIR

CUDDALORE TAMILNADU

ANDROTH KAVARATTI

NAGAPPATINAM COCHIN THIRUVANANTHAPURAM

MINICOY

KODAIKANAL RAMESHWARAM TUTICORIN

NANCOWRY

KANYAKUMARI CAMPBELL BAY

REFERENCES SOI GPS STATIONS WITH VSAT( OPERATIONAL) SOI GPS STATIONS WITH VSAT( PROPOSED) PERMANENT GPS STATIONS

REAL TIME GPS DATA Under the modernization of Indian Tide Gauge Network in Post Tsunami Scenario, several tidal observatories across the East & West Coast of India, Andaman & Nicobar Islands and Lakshadweep Islands have been established.. established 20 of these stations are equipped with dual frequency GPS Receivers collocated with Digital Tide Gauges Gauges.. These stations have Real Time Data Transmission (RTDT) facilities through VSAT.. VSAT GPS Data is received, archived and processed at National GPS Data Centre Centre.. REMOTE VSAT SETUP

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REDEFINITION OF INDIAN VERTICAL DATUM DENSIFICATION GTS Levelling was carried out between 1850 to 1905 1905.. Indian Vertical Datum was first time defined in 1905 1905.. Then no Invar staves were used used.. No Fore – Back Levelling was done done.. Most of the BMs established then do not exist on the ground now due to developmental activities and vagaries of the weather weather.. Without Gravity Values Values.. It was assumed that water level of Arabian Sea and Bay of Bengal is same, which is infact different due to different salinity and consequent different density density.. Levelling was not adjusted in single all India Level Network Network.. Hence necessary to Redefine Vertical Datum.. Datum With the requirement of height accuracy within few centimetres and to achieve water flow criterion, we needed to redefine vertical datum datum..

In past, the requirement of contours was 10 m / 20 m in plain areas and 100 m / 200 m in the hilly area (due to sparse developmental activities) but now owing to population pressure and need for faster development for micro level planning, requirements have increased to get the contour at 50 cm / 1 metre metre.. We are facing more drainage problem, more sewer lines are required, to solve water problem we need to interlink rivers rivers.. Essential ingredient in all these works is precise vertical control i.e. precise level line which meets water flow criteria criteria.. To achieve this an initiative to redefine the vertical datum for the whole country has been taken up up.. In this project, it is envisaged to carryout the High Precision Levelling alongwith the gravity observations to obtain the geopotential numbers numbers.. These newly defined heights will be based on the geopotential numbers and Helmert Orthometric Heights which are scientifically correct heights and follows the water flow criterion criterion..

The entire project is divided in two phases: First Phase : To form the main frame of vertical control for the entire nation (~45000 Km in both direction). Second Phase : Based on the main frame of vertical control further densification of the vertical control will be done (~100000 Km in both direction). Phase – I of the Project for Redefinition of Indian Vertical Datum has been completed. Phase-II for the densification of Levelling newtwork will be undertaken on allocation of budget. Precise Vertical control is also very important ingredient for national development, so, like any other developed country, India needs to have this framework at the earliest. Proposal for allocation of Budget to the tune of Rs. 15 crores has been submitted for approval.

MAJOR UTILITIES Interlinking of Rivers Rivers.. Flood Control Control.. Development of efficient Drainage and sewer line system system.. Coastal Hazard Line Delineation Delineation.. High value infrastructural and engineering projects projects..

PROJECTS IN PIPELINE Virtual Reference Station Network – Corrections issued by a beacon installed at continuous operating GPS Reference Stations, when received by an observer in the area of work can find out position with sub sub--metre accuracy with single small portable receiver . It will enable quick mapping and updation of maps, cadastral mapping using single receivers receivers.. It can be used for the tracking and navigation (Rail/Road/Air) and for many other applications such as maintaining accurate land records and land uses, Infrastructure Project Planning etc etc.. With GCP Library Stations already in place, such a network is being conceived and a proposal is in the final stages of preparation for submission submission.. It is estimated that total cost of the project will be in tune of Rs 500 crores crores..

CONCLUSION Provision of dense control at a spacing of less than 20 km will benefit the user community in many ways ways.. The biggest benefit will be the standardisation of our land records, which is hitherto in very bad shape inviting number of litigations litigations.. So far our land records are mostly on Cassini Projection, which is a equidistant projection projection.. Distortion of area and shape are functions of distance from central meridian meridian.. Scale is true along central meridian only only.. Because of which it can not be used for bigger areas areas.. Therefore, land records are maintained in pieces and seamless record is not possible/available possible/available.. It is envisaged in Land Record modernisation programme of Government of India that now onwards all the records will be based on Phase I, II and III GCPs on WGS WGS--84 Datum with UTM Projection Projection.. Using GCPs, control will be brought to village through GPS and thereafter using Total Station boundaries of land parcels will be measured/demarcated measured/demarcated..

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CONCLUSION

Contd.

Once the GCP Phase Phase--III Project is completed, denser network of control will be available available.. In future the GCP points are proposed to be equipped with the facilities to transmit the differential corrections to the user community in the form of Continuous Operating Reference Stations / Virtual Reference Station Station..