Back-sighting the history of Surveying

March 08, 2012

Last November 28- December 2, 2011, I had the chance to participate in a course for GPS data analysis and modelling (GDAM) for scientific and practical application workshop held at the National Engineering Center of UP Diliman.

Part of the itinerary is a day of field trip to the major research agencies that uses Global Positioning Systems (GPS) in the modelling and analysis of crustal movements for their respective scientific applications.

The agencies that we have visited are the Philippine Institute of Volcanology and Seismology (PHIVOLCS), Manila Observatory and the National Mapping and Resource Information Authority (NAMRIA).

At PHIVOLCS we get a peek on how the GPS data from continuous and campaign sites have been archived, processed and delivered. These data will then be used further for the analysis of crustal movements specifically along the Philippune Fault as well as the deformation and movements on active volcanoes in the Philippines such as Mayon and Kanlaon. Having been part of the PHIVOLCS-GPS Team for quite some time, I am already familiar with the processing scheme using Bernese 5.0 which is Windows-based. In this workshop however, we are taught on how to process and model GPS data using GAMIT-GLOBK and DEFNODE respectively. GAMIT-GLOBK and DEFNODE both runs in LINUX.

Another office that we have visited is the Manila Observatory where an IGS station -PIMO is located.

A short introductory GPS presentation was given during our visit.

Of course we also got sight of the only International GPS Service (IGS) station in the Philippines for the longest time since 1980's I guess. That is PIMO appearing in the photo below. I think NAMRIA has recently added another IGS station, PTAG which is located at their office in Taguig. So in total, there are already 2 IGS stations that's tied into the International Terrestrial Reference Frame (ITRF) in the Philippines to account for the movement of our 7107 islands that's being tectonically active and bounded by four major tectoic plates.

After the Manila Observatory, our next stop is NAMRIA where the Data processing and archiving of the Philippine Active Geodetic Network (PAGEnet) takes place.

After the lecture and introduction of the data monitoring procedures done in the PAGEnet Data and Control Center, we got the chance to tour around the museum located at ground floor of NAMRIA. The surveying instruments of the past were carefully preserved and displayed within the room.

Berger Theodolite