Guidelines on RTK-GNSS Use in Lot Surveys

RTK-GNSS technology may be used for conducting all types of lot surveys requiring tertiary accuracy.
Devices used must be Dual Frequency Receivers meeting specifications outlined in Section 202(g) of DMC 2010-13 (Manual on Land Survey Procedures).
Real-Time Kinematic surveys require at least two GNSS receivers: one base station and one rover.

Base station GNSS receiver must be positioned at a location with an unobstructed sky view and a horizon clearance of at least 15 degrees in all directions.
Base station coordinates must be known in the WGS-84 geodetic system.
Rover receiver must be mounted on a range pole, stabilized with a bipod to prevent movement during observations.

Survey operations should follow procedures stated in Sections 20-27 of DMC 2010-13.
Survey areas need horizon clearance of at least 15 degrees in all directions at all lot corners unless augmented by Electronic Total Station (ETS).
Use of ETS is mandatory for corners obstructed by buildings, thick tree canopies, existing concrete fences, building walls, and beneath high voltage power lines or communication facilities.
RTK receivers can be placed directly on corners coinciding with concrete fences.
Root Mean Square (RMS) error values must be monitored; values exceeding 70 necessitate station relocation, with a preferred value of 35 or below for precision.
Minimum RTK observation time per lot corner is 2 minutes, tracking at least 5 satellites with good geometry.
RTK initialization must precede data collection, maintaining satellite lock and base station radio signals during station transfers.
A baseline between intervisible points, 200 meters to 1 kilometer apart, must be established near the lot using RTK.
Distance measured by RTK must be compared to ETS measurements; discrepancies not exceeding 1 cm per 50 meters or 20 cm per kilometer are acceptable, ensuring tertiary accuracy of 1:5,000.

Complete documentation of instrument details including antenna type, serial number, and setup.
Receiver information detailing type, brand, model, serial number, and frequency.
Specification of survey style (e.g., RTK, Fast Static).
Date, weather condition, and precise location including barangay through island level.
Project identification by name or description.
Base station data including station name, file name, monument type, dimensions, inscription, antenna heights (slope and true vertical), and timing of observations.
Rover unit data similar to base station, with provisions for multiple rovers.

DENR Regional Offices are responsible for acceptance, processing, and verification of survey returns conducted with RTK-GNSS.
Procedures for handling these returns follow the Manual on Land Survey Procedures.

The guidelines become effective fifteen (15) days after publication in a newspaper of general circulation.
Implementation is also contingent upon acknowledgment by the Office of the National Administrative Register (ONAR).
The circular is officially signed and promulgated by the Officer-in-Charge Director of the Land Management Bureau.