Law Summary
Scope and Coverage
- Applies to all isolated survey returns including:
- Group Settlement/Townsite Subdivision Surveys
- Public, Private, Amendment, Conversion, and Government Land Surveys
- Friar Land Estate Surveys
- Other specialized land surveys
Key Definitions
- Detailed definitions of critical terms such as:
- Amendment, Conversion, and Isolated Surveys
- Common Points and Reference Points
- Government Land Surveys and Private Land Surveys
- PRS92 and WGS-PRS92 Transformation Parameters
- Transformation and Verification processes
- Definitions clarify legal and technical concepts underlying surveys
Revised Inspection, Verification and Approval of Survey (IVAS) Workflow
- Stepwise procedure for processing survey returns, including:
- Submission and preliminary examination
- Fee assessment and survey registration
- Digital projection on Land Information Map (LIM)
- Computational verification including GPS data and transformation accuracy
- Cartographic review and final approvals
Supplementary IVAS Procedures for Non-Compliant Surveys
- Special verification measures for surveys using conventional equipment
- Focus on GPS survey data compliance, transformation accuracy, and digital projection
Survey Return Documentation Requirements
- Mandatory attachments for isolated survey returns:
- Letter of transmittal, original drafting film plan, tax declaration
- Original notarized field notes, GPS returns, PRS92 control map
- Computations, certificates (GE, GPS instrument registration), title certifications
- Digital copies and survey notifications
Verification Process
- DENR supervising Geodetic Engineer verifies completeness and accuracy
- Requirement to endorse and sign all documents during verification
- Procedures for handling incomplete or erroneous submissions
Recovery and Use of Common Points
- Criteria for selecting and utilizing control stations and lot corners for transformation:
- Number, distribution, and accuracy of common points critical
- Minimum six (6) well-distributed points recommended
- Redundant points serve as check points for quality control
- Options if residual errors are unacceptable include re-computation or alternative methods
Methods for Locating Common Points
- Use of GPS receivers in open areas with at least 15° line-of-sight to satellites
- Use of electronic total stations in obstructed or vegetated sites
Transformation Formulas
- Use of Helmert's Four-Parameter Equation:
- Rotation, scaling, and translation to preserve shape
- Requires at least two control points; more for least squares adjustment
- Use of Affine Transformation:
- Six-parameter model for more complex distortions
- Requires at least three control points; more improve accuracy
Supplementary Regulations
- Authority granted to Supervising Undersecretary to issue additional regulations as needed
Penalties
- Violations by Geodetic Engineers or contractors can result in non-acceptance of survey returns
- Subject to disciplinary action as per DAO 2007-29 Sections 73 to 80
Repealing Clause
- Previous inconsistent DENR orders or issuances are superseded, amended, or repealed
Effectivity
- The rules take effect 15 days after publication and upon acknowledgment by ONAR
This comprehensive legal framework ensures standardized, accurate, and efficient handling of land surveys in the Philippines anchored on PRS92 standards.