Must need a good knowledge in below items
1. TOPOGRAPHIC SURVEYS
- Detail and Feature Surveys
- Contour and Thematic Mapping
2. ENGINEERING SURVEYS
- Pre-computation
- Setting Out Survey for Construction & Engineering Works
- As-built Survey
- Pipeline & Cable Laying Survey (Power, Sewer, Etc)
3. GEODETIC SURVEYS
- Control Network Surveys
- Levelling and Benchmarks
4. CADASTRAL SURVEYS
- Alienation of State Land
- Land Subdivision & Amalgamation
· Subdivisions For Land and Strata Titles
- Resurvey of Lot
- Foreshore Survey
5. MONITORING SURVEYS
- Ground Settlement Monitoring
- Existing Structure Monitoring
SURVEY CONTROL ACCURACY STANDARDS
For The Establishment of Both Horizontal and Vertical Controls, The Local National Grid SVY21 Coordinate System Shall Be in Reference for Horizontal (Easting, Northing) Components and Singapore Height Datum (SHD) For Vertical (Elevation) Component. This Is in Accordance with The LSB Directive on Engineering and Hydrographic Survey Practices.
HORIZONTAL CONTROL
The LSB Directive on Engineering and Hydrographic Survey Practices Requires the Use Of At Least Four (4) ISN Markers to Establish the Horizontal Datum for Every Survey. The ISN Markers Shall as Far as Possible, Encompass the Site Under Survey, And Should Be Used Only If the Residuals in Northing and Easting Co-Ordinates Are Within 0.020 M Of the Recorded ISN Values for GPS Surveys by Taking Reference from The Singapore Satellite Positioning Reference Network (Sirent). A GNSS Survey Would Also Be Required If There Are Less Than Four (4) Stable or Intact ISN Markers. For Further Details on Establishment of ISN Markers, Please Refer to The Guidelines and Specifications for GPS Surveys of ISN Markers. When A Traverse Is Created, The Minimum Closure Standard for Horizontal Control Is 1:20,000 With Angular Closure Of 5ÖN, Where N Is the Number of Angle Stations. Summary As Below: Minimum Closure Standard 1:20,000 Angular Closure 5ÖN
VERTICAL CONTROL
The Vertical Datum Shall Be Derived From At Least One Reliable Vertical Control Points (VCP), Verified With At Least Two Witness Marks Established By SLA. All Levelling Shall Be Executed by Standard Precise Levelling Procedures. Where A Local Vertical Control Is to Be Established for Allowable Height Accuracy Of 5 Cm, The Geometric Geoid Model, Sgeoid09, established by SLA Shall Be Adopted to Convert Ellipsoidal Heights, Obtained in Accordance with The Recommended Procedure Published By SLA, To Heights in Reference to SHD (Https://Sirent.Inlis.Gov.Sg/Servicessgeoid09.Aspx). The Minimum Closure Standard for Vertical Control Is 6ÖK, Where K Is the Distance in Kilometres Between the Two Points Being Considered. Summary As Below: Minimum Closure Standard 6ÖK 3.3 Singapore Satellite Positioning Reference Network (Sirent) GNSS RTK Survey Supplied with Real Time Correct.
