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Effective Tools for Cadastral Surveying in Latin America and the Caribbean DR. GRENVILLE BARNES.

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Presentation on theme: "Effective Tools for Cadastral Surveying in Latin America and the Caribbean DR. GRENVILLE BARNES."— Presentation transcript:

1 Effective Tools for Cadastral Surveying in Latin America and the Caribbean DR. GRENVILLE BARNES

2 Scope of Land Administration Activities in LAC Scope of Land Administration Activities in LAC Development of a GPS Methodology for Property Surveying Development of a GPS Methodology for Property Surveying –Challenges and Design Criteria –Cadastral Context –Equipment Acquisition and Transfer –Geodetic Infrastructure –Office and Field Procedures Evolution of Methodology Evolution of Methodology –Toolbox Approach –IGS Stations as control –Real-time corrections Maintaining currency of property information Maintaining currency of property information Conclusions and Challenges Conclusions and Challenges OutlineOutline

3 NO SURVEY SOLUTION SURVEY AND MAP 6,200,000 PARCELS INFORMAL PROPERTY (UNSURVEYED) [est. 80% Rural & 60% Urban] GOVERNMENT AWARENESS WILLINGNESS FUNDING AVAILABLE Problem Statement

4 Over the past 10+ years governments in Latin America and the Caribbean have embarked on numerous ‘land administration’ projects with an estimated total cost of over US$1billion Over the past 10+ years governments in Latin America and the Caribbean have embarked on numerous ‘land administration’ projects with an estimated total cost of over US$1billion This funding has come from the countries themselves, the international banking organizations (World Bank and IDB) and the bi-lateral donors (USAID, MCC, United Kingdom, France, Canada, Japan, Holland etc.) This funding has come from the countries themselves, the international banking organizations (World Bank and IDB) and the bi-lateral donors (USAID, MCC, United Kingdom, France, Canada, Japan, Holland etc.) Effective Tools...

5 CENTRAL AMERICA Belize (IDB) Guatemala (WB) Honduras (WB, EU, IDB) El Salvador (USAID, WB) Nicaragua (WB, MCC) Costa Rica (IDB) Panama (WB, IDB) CENTRAL AMERICA Belize (IDB) Guatemala (WB) Honduras (WB, EU, IDB) El Salvador (USAID, WB) Nicaragua (WB, MCC) Costa Rica (IDB) Panama (WB, IDB) SOUTH AMERICA Guyana (IDB, DFID) Colombia (IDB) Ecuador (IDB, WB) Peru (IDB, WB, USAID) Brazil (IDB) Bolivia (WB, USAID, Neth, Nordic) Paraguay (IDB) Suriname (Neth. IDB) SOUTH AMERICA Guyana (IDB, DFID) Colombia (IDB) Ecuador (IDB, WB) Peru (IDB, WB, USAID) Brazil (IDB) Bolivia (WB, USAID, Neth, Nordic) Paraguay (IDB) Suriname (Neth. IDB) CARIBBEAN Jamaica (IDB) Trinidad & Tobago (IDB) Bahamas (IDB) Dominican Republic (IDB) Antigua & OECS Countries (OAS) Turks and Caicos (DFID) CARIBBEAN Jamaica (IDB) Trinidad & Tobago (IDB) Bahamas (IDB) Dominican Republic (IDB) Antigua & OECS Countries (OAS) Turks and Caicos (DFID) [http://www.property-registration.org/Project-list.html] MEXICO (WB & IDB) Land Administration Projects and Funding Agency

6 Cadastral Methodology (challenges and design criteria)

7 The cost of conventional property surveying approaches exceeds the value of the land The cost of conventional property surveying approaches exceeds the value of the land The time required to survey large numbers of properties far exceeds the typical length of land administration projects (4 - 5 years) The time required to survey large numbers of properties far exceeds the typical length of land administration projects (4 - 5 years) LAC countries (circa 1994) do not have the geodetic infrastructure to support the use of GPS LAC countries (circa 1994) do not have the geodetic infrastructure to support the use of GPS Shortage of modern technology and qualified surveyors Shortage of modern technology and qualified surveyors Major Challenges

8  Performed by Qualified Professionals (education/experience)  Minimum requirements dictated by law  Calibrated Equipment  Measurements checked Independently  Surveys Georeferenced to national coordinate system  Performed by Qualified Professionals (education/experience)  Minimum requirements dictated by law  Calibrated Equipment  Measurements checked Independently  Surveys Georeferenced to national coordinate system Fundamental Principles of Cadastral Surveying

9  Efficient (short occupations)  Long Base Lines (minimize control)  Less Costly (than Conventional Methods)  Realistic level of accuracy  Realistic level of Technology  Flexible  Incorporate quality control mechanisms The methodology must be needs driven Design Criteria for GPS Methodology

10  Accuracy = f (land value, land use, parcel size, culture,…..)  Cadastral Function of Coordinates:  relocation of property corners  re-monumentation  abstract representation  Accuracy = f (land value, land use, parcel size, culture,…..)  Cadastral Function of Coordinates:  relocation of property corners  re-monumentation  abstract representation In rural areas where property values are relatively low, sub-meter accuracy is adequate for fulfilling the three functions 1 m Realistic Accuracy

11 Cadastral Methodology (equipment acquisition)

12 Classes of GPS Positioning $35,000 increasing complexity(and Skill Requirements)and cost$100 mm 0.5 m 1m cm 15m 5m RELATIVE/ DIFFERENTIAL POSITIONING POINT ( ABSOLUTE ) POSITIONING A P P R O X I M A T E A C C U R A C Y geodetic grade mapping grade navigation / recreational grade dm

13 Cadastral Methodology (geodetic infrastructure)

14 Motivation for a New Geodetic Infrastructure Inadequacy of Local Datums Inadequacy of Local Datums –Incompatible with GPS Methods Peru Peru –Large regional distortions (e.g., The Coast vs. the Andes Valleys) The Bahamas The Bahamas –Different NAD27 Realizations on Most Islands Crumbling Infrastructure: Crumbling Infrastructure: –Attrition of Physical Marks –Loss of Records

15 Motivation for Not Delaying in Adopting ITRF

16  Reference points with coordinates referenced to WGS84/ITRF  In-country base stations  Calibration Site (10-20 Points)  local reference points  transformation parameters to convert local datum to/from WGS84  Reference points with coordinates referenced to WGS84/ITRF  In-country base stations  Calibration Site (10-20 Points)  local reference points  transformation parameters to convert local datum to/from WGS84 Geodetic Infrastructure

17 GPS METHODOLOGY (field and office procedures) GPS METHODOLOGY (field and office procedures)

18 CALIBRATION OF EQUIPMENT OFFICE PREPARATION FIELD WORK POST-PROCESSING VERIFICATION DRAW CADASTRAL PLAN · before first use · changes in receiver, software, antenna, firmware, data collector · create data dictionary · recharge batteries · verify available memory · program receiver · notify base station · occupy reference points · reconnaissance of parcels · draw provisional field sketch · occupy parcel corners · collect satellite data · enter attribute data · reoccupy corners · draw final field sketch · transfer data to laptop  transfer data to office computer  obtain data from 2 base stations  differentially correct GPS observation  export coordinates to spreadsheet  compare corrected coordinates: - base stations 1 and st and 2 nd occupations  calculate means (if acceptable)  export coordinates to mapping software  draw cadastral plan  submit documents to Cadastre Office GPS Methodology

19 Results Occupation times ( min.) Occupation times ( min.) Variable base lines (2 km km) Variable base lines (2 km km) Different types of GPS receivers Different types of GPS receivers Two base stations Two base stations Occupation times ( min.) Occupation times ( min.) Variable base lines (2 km km) Variable base lines (2 km km) Different types of GPS receivers Different types of GPS receivers Two base stations Two base stations Obtained submeter accuracy with: Obtained submeter accuracy with: –Occupations of 1 min. –Base lines up to 200 km –Using Trimble Pro XL –Verified with dual base stations and double occupation Obtained submeter accuracy with: Obtained submeter accuracy with: –Occupations of 1 min. –Base lines up to 200 km –Using Trimble Pro XL –Verified with dual base stations and double occupation Initial Tests (UF + Albania)

20 ALBANIA BELIZE NICARAGUA Field Testing GPS Methodology

21 PERU ECUADOR TRINIDAD Field Testing GPS Methodology

22 Blunder Trapping:  multipathing  no of satellites and geometry  “trailing” off point  wrong base station coordinates  change in receiver configuration (e.g. datum) Accuracy Check:  Receiver meets sub-meter accuracy  occupation times sufficient Quality Control Issues

23 Calibration:  checks receiver meets sub-meter accuracy  checks occupation times sufficient Local Reference Points:  checks wrong base station coordinates entered  checks change in receiver configuration Double Base Station:  checks wrong base station coordinates  second BS acts as back-up Dual Occupation:  checks for multipathing  checks for trailing Quality Control Mechanisms

24 EVOLUTION OF GPS METHODOLOGY

25 Evolution of the Cadastral Surveying Methodology Initial Concept – dGPS Initial Concept – dGPS Field Experience (Belize, Peru, Albania, etc.) Reveals Complexity of the Problem Field Experience (Belize, Peru, Albania, etc.) Reveals Complexity of the Problem The Methodology Evolves to the ‘Toolbox’ Concept The Methodology Evolves to the ‘Toolbox’ Concept Addition of Surveying Tools dGPS Real-time dGPS Compass Laser Rangefinder Orthophotography dGPS Tape

26 Boundary Types & Surveying Methodologies Type (i) : Surveyed directly using GPS - Post, fence and bushes not visible in aerial photography. Type (ii) : Surveyed by offsets using GPS, or by photo- identification, if clearly visible in photography. Could also serve as supplementary ground control.

27 Eccentric Observations

28 Boundary Types & Surveying Methodologies Type (iii) : Surveyed by GPS and/or by photo-identification, if clearly visible in photography. Could also serve as supplementary ground control if clearly photo-identifiable. Types (iv and v) : Surveyed by GPS if accessible and/or by photo-identification, if not accessible and clearly visible in photography.

29 Type (vi) Delineated theoretically, can be set out using real-time dGPS. Boundary Types & Surveying Methodologies

30 BS 1Rover BS 2 Rover Reference Marks Cadastral Survey Methodology (2 Central Base Stations)

31 Rover Reference Mark BS/IGS Local BS1 (Local & Central Base Stations) Cadastral Survey Methodology Local BS2

32 Corrections (Real Time) Reference Marks Rover BS Geostationary Communication Satellite (e.g. Omnistar) (Real-Time Corrections via Satellite Cadastral Survey Methodology

33 Maintenance Issues

34 Process & Constraints to Cadastral Data Maintenance National Cadastre Agency Local Government Private Sector Surveyors CADASTRAL DATABASE UPDATED PROPERTY DATA (Registry, Tax Roll, Zoning) PROPERTY TRANSACTIONS (Parcel Mutations ) Lack of standards Incompatibility Lack of resources Lack of legal responsibilities Lack of technical capacity Competing interests Competing mandates Lack of Inter-agency coordination Lack of legal framework Incompatibility Lack of technical solution Lack of over-sight entity Informal transactions Limited perceived benefits High cost of surveys Cultural of informality Limited access to services Lack of awareness Lack of information CONTRAINTS

35 Conclusion Sub-meter GPS is now being used widely in several land administration projects Sub-meter GPS is now being used widely in several land administration projects It offers a more efficient, less costly solution in certain circumstances, but not the total solution It offers a more efficient, less costly solution in certain circumstances, but not the total solution Even though benefits are proven, GPS technology transfer is still an obstacle Even though benefits are proven, GPS technology transfer is still an obstacle GPS procedures need to be integrated into a complete business process (office to field to office) GPS procedures need to be integrated into a complete business process (office to field to office) Need for technology extension agents (e.g. agriculture) Need for technology extension agents (e.g. agriculture)


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