28May2017

OSGOF

Geodesy

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Geodesy, also named geodetics, a branch of earth sciences, is the scientific discipline that deals with the measurement and representation of the Earth

including its gravitational field, in a three-dimensional time-varying space

 

Field and Geodesy Division  

This Division is under Department of Geodesy and Special surveys.

 

Activities

-          Provision of geodetic controls nationwide (1ST  and 2ndorder);

-          Densification and Extension of such Controls;

-          Responsible for maintenance of established controls;

-          Responsible for field and related surveys;

-          Construction of 1st and 2nd order monuments through the six zonal headquarters and thirty-six field Offices; and

-          Maintains a database of coordinates and survey information

-          Responsible for field and related surveys

 

Products Available

(i)             Coordinate Data for Trig Station

(ii)            Coordinate Data for GPS Stations (1988/89 GPS Observations in hard and soft copies)

(iii)           Coordinate Data for GPS Control Extension project (Since 2006)

(iv)           Coordinate Data for Cross River State GIS Project

(v)            Coordinate Data for Mines and steels Project

(vi)           Coordinate Data for NASRDA GPS Project (1st order GPS Point – about 108 Points across the Country) – In hard and soft copy.

(vii)          Street Guides of State capitals – Data for ground trothing/ verification project that was executed by all the Chief Resident Surveyors. (no records)

(viii)         Equipment (Hardware and software) 

Software

-          ArcGIS 9.3 (2011)

-          Cola bus ( for planning and adjustment of geodetic networks )

-          Leica Geo-office (3 version)

-          TBC (2.3)

-          Survey spectrum (for sokkia)      

Hardware

-           Hp Proliant Server (Window 2003 Server) that hosts the control data.

(ix)           Files /Reports for Geodetic Control Projects

(x)            Coordinate Data for first order Traverses ( mainly for western  region)

(xi)           Maps Shewing the location of all the Observed GPS Pillars (1st and 2nd order )

(xii)          Maps shewing both the old Trig pillars and the corresponding GPS observed pillars.

Special Survey Division

Special Surveys Division is one of the four divisions under the Department of Geodesy and Special Surveys, and headed by Surveyor Ugwuadu C.O. It started functioning as a Division in 2006, and it is saddled with the following activities:

(1)           Right-of –Way of the Federal Government of Nigeria Roads;

(2)           Right-of –Way of Railway lines;

(3)           Right-of –Way of Electric Transmission lines and Pipelines;

(4)           Tidal measurement and monitoring for mean-sea-level determination (Hydrograph Surveying);

(5)           Bathymetric survey of Continental shelf;

(6)           Monitoring of Coastal Erosion (erosion control survey)

(7)           Surface and under water positioning;

(8)           Geodetic Surveying including magnetic observation, Gravity  measurement and deformation surveys and subsidence for subsidence monitoring  for heavy engineering structure such as bridges, Nigerian National Petroleum Corporation (NNPC) Oil Tank firms;

(9)           Tunnels at mining sites, Dam sites, etc;

(10)         Specialized survey for disaster such as Tsunami, earthquake, landslides, etc, desertification and gully erosion monitoring;

(11)        Seismic Surveys; and

(12)        Floor plain mapping.

 

Available Products (Deliverables):

(i)             Survey Data on ROW of Roads and Railways:

(ii)            Mining Survey: Mining Survey measurement is carried out in collaboration with other Federal Government ministries and agencies such as Ministry of Environment, Ministry of Mines and Steel, Ministry of Agriculture and Forestry, etc ;

(iii)           Tidal Measurement/Monitoring Data: Monitoring and determination of mean-sea-level on four (4) tidal stations were established in Nigeria.  These stations are located in Lagos (Apapa), Warri, Port-Harcourt and Calabar. Quarterly observations are taken and quarterly tidal reports are taken;

(iv)           Gravity measurement and deformation survey records: Field Description Sheets for Gravity  measurement and deformation survey reside in Lagos and Kaduna Data Depot offices;

(v)            Gravitational Variation, magnetic variation for selected points

(vi)           Mapping Gully Erosion sites: Maps showing the height values of erosion prone area at different epochs (monthly);

(vii)          Imageries: Some satellite imageries had been procured for Flood Plain Mapping, for instance, Usman Dam in Bwuri Area Council of Federal Capital Territory;

 

Available Data: Available Data are in softcopy and hardcopy in format; and

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