The Philippine Active Geodetic Network (PAGeNet) is a network of permanently-installed, continuously operating geodetic reference stations that utilizes signals from Global Navigation Satellite Systems (GNSS) to provide real-time, high-precision geographic position data to users via the Internet. Data from the network may be used in a wide array of applications such as surveying, mapping, navigation, crustal deformation studies, and meteorology. The PAGeNet is an important component of NAMRIA’s strategic plan to modernize the Philippine Geodetic Reference System (PGRS) by year 2020. It provides a continuous link to the International Terrestrial Reference Frame (ITRF) and is one of the Agency’s contributions to the development of a sustainable global geodetic reference frame as called for by the United Nations General Assembly through Resolution No. 69/266 of 26 February 2015 (A Global Geodetic Reference Frame for Sustainable Development). Established in 2008, the PAGeNet currently comprises of 61 active geodetic stations installed nationwide. Three of its stations (PTAG, PPPC, PGEN) are already incorporated in the International GNSS Service (IGS) Tracking Network.



The AGS are permanent GNSS stations of the PAGeNet that receive satellite signals twenty-four (24) hours a day for precise determination of geographic position (latitude, longitude and height). All sites are selected based on the required and desired site characteristics recommended by the IGS for permanent reference stations. The stations are equipped with geodetic-grade GNSS receiver and antenna to ensure quality GNSS data. Supplementary sensors such as meteorological and tilt sensors that gather temperature, humidity, pressure and pillar deflection data are also installed in selected sites. The AGS are connected to the DCC via a Virtual Private Network (VPN) using wired or wireless internet connection. Most of the stations utilizes solar power to operate.





Data from the remote sites are sent to the DCC which serves as the Information Communication Technology (ICT) facility of the PAGeNet. Network monitoring, online processing, as well as storage and distribution of geographic data are being carried out in the DCC which is manned by a pool of technical staff. The DCC is equipped with high-end data processing and storage resources to efficiently monitor and manage the data generated by the PAGeNet.



Through the years, GNSS has established its niche in the surveying and mapping industry with its cost-efficient, reliable, and precise means of position determination. Autonomous positioning with GNSS (i.e. one GNSS receiver and four or more satellites in view) usually yields a position within +/- 3 to 10 meters. For applications that require higher precision, relative positioning is usually used wherein data from a base station (with precisely known coordinates) are used to correct the GNSS data gathered from a rover receiver. This technique works by reducing/eliminating distance dependent errors common to both base and rover receivers thus yielding better positioning results. Traditionally, these base stations are temporary installations, only set up based on the needs of a project. The proliferation of permanently-installed continuously operating reference stations, such as the PAGeNet’s AGS, provides a viable alternative by eliminating the need to set up a separate base station. This, in turn, ensures efficient utilization of resources and improves productivity while maintaining consistency of positioning throughout the coverage area. PAGeNet data may be sent in post-processed or real time mode. For post-processing, RINEX files of the AGS are available for download at different logging intervals and file lengths. Real time corrections, meanwhile, are sent through RTCM messages using the NTRIP. RTCM – Radio Technical Commission for Maritime Services NTRIP – Networked Transport of RTCM via Internet Protocol