1. PRS92 Bonifacia Daet Sylvia Esperanza
The Philippine Reference System of 1992
Bonifacia Daet
Sylvia Esperanza

2. OUTLINE Introduction History Datum Quantities PRS92 Parameters
Significance to Philippine Mapping
On-going Programs
From 1901 to 1911, the US Coast and Geodetic Survey established several small triangulation networks which had different origins. In 1911, these small networks were consolidated into the Luzon Datum and became the primary reference of all surveys in the Philippines.

3. National network of geodetic control points (GCPs)
Philippines’ standard coordinate reference system for all survey and mapping activities
National network of geodetic control points (GCPs)
established using the Global Positioning System (GPS)
Implemented in through an Australian-assisted project - Natural Resources Management & Development Project (NRMDP)
From 1901 to 1911, the US Coast and Geodetic Survey established several small triangulation networks which had different origins. In 1911, these small networks were consolidated into the Luzon Datum and became the primary reference of all surveys in the Philippines.

4. Philippine Triangulation Network (1901 to 1911)
Why Do We Need PRS92?
Philippine Triangulation Network
Established in by the US Coast and Geodetic Survey
Narrow chains of 2nd order triangulation stations which had different origins
Consolidated into the Luzon Datum in 1911, however:
No contiguous mean sea level datum established
Disregarded geoid-ellipsoid separation
Old geodetic data set had large errors - up to 56m in latitude & 80m in longitude
Philippine Triangulation Network (1901 to 1911)
From 1901 to 1911, the US Coast and Geodetic Survey established several small triangulation networks which had different origins. In 1911, these small networks were consolidated into the Luzon Datum and became the primary reference of all surveys in the Philippines.
Analysis of the old data set reveals large errors (punching and typographical- up to 56m in lat and 80m in long).
Old second order trig. Stations were recomputed and readjusted– thus giving a modified G.P. and a new name– Philippine Reference System 1992(PRS’92)
There is a need for an accurate homogeneous national geodetic framework for improved economic status through better land management.

5. The Philippine Reference System of 1992 (PRS92)
datum quantities are the same as Luzon 1911 datum except for the Geoid- Ellipsoid separation (N=0.34m).
actually modified Luzon datum that has a more accurate and homogeneous set of coordinates
A new network was established using GPS-- then called it the Geodetic Network of the Philippines
Local coordinate system-LUZON DATUM 1911
All maps in Phil. were made using this datum
This new network has a more accurate and homogeneous set of coordinates, referred to the Clark 1866 spheroid and the modified Luzon Datum which is named Philippine Reference System 1992.
Semi-minor Axis
Semi-major Axis
Flattening (f) b a

6. Comparison Between PRS92 and GDA94
Datum
Philippine Reference System
Geocentric Datum of Australia
Reference Ellipsoid
Clarke 1866
GRS 1980
Semi-major axis
6,378,206.4 m
6,378,137.0 m
Inverse flattening

7. The Philippine Reference System of 1992 (PRS92)
NRMDP has established a new geodetic control network consisting of:
330 1st order
101 2nd order
36 3rd order

8. STANDARDS OF ACCURACY - (national geodetic network)
 First Order : 10 Parts Per Million ( 10 PPM)
 1 cm/Km 1/100,000
 Second Order : 20 Parts Per Million ( 20 PPM)
 2 cm/Km 1/50,000
 Third Order : 50 Parts Per Million ( 50 PPM)
 5 cm/Km 1/20,000
 Fourth Order : 100 Parts Per Million ( 100 PPM)
 10 cm/Km 1/10,000

9. PRS92 Transformation Parameters
NRMPD also developed 7 parameter-transformation model relating PRS92 to WGS84 and vice-versa
For GPS users, the following transformation parameters will be necessary when undertaking local surveys. They relate the WGS84 Datum, to which all GPS data is referenced to PRS92 on the Luzon Datum. These parameters are applied to WGS84 geocentric cartesian coordinates to give cartesian coordinates of the PRS92 datum which will then be transformed to geographical PRS92 coordinates.

10. Significance of PRS92
PRS 92 standardize the mapping system in the Philippines to ensure :
Consistency of the country’s spatial datasets (topography, land use, boundaries, roads, environment, and natural resources, structures, etc)
Efficient use of previously acquired data
Availability of precise and accessible data for all users
Improvement in the land administration and tenure system which forms the basis of all land transactions dealing with land
Improvement in the surveying and mapping capabilities and support to vital government programs and projects
Standardize the mapping system in the Philippines so that a particular point on the ground will have only one location in any official Philippine map.
Provides the means through which base and thematic data sets can be consistently inter-related geographically

11. Triangulation Networks of the Philippines (1901 – 1911)
THE NATIONAL GEODETIC FRAMEWORK
Triangulation Networks of the Philippines (1901 – 1911)
Densification (Horizontal)
Homogeneous
National Spatial
Data Infrastructure
LUZON DATUM (1911)
Active Geodetic
Network
GND
Leveling
NRMDP ( )
Gravity Survey
Tide Station
PRS92
Program
PRS92
Topo base map
DTI
Cadastral data
ENR Data
330 -1st order
101 -2nd order
36 -3rd order
National
GNIS
Regional

12. References:
Galano, E. Why Surveyor Ignores the Earthcrust Drift.
Gatchalian, R. 2006, Manual on GPS Surveying, CGSD-NAMRIA
Gatchalian, R. GPS Basics v 1.6
Geoscience Australia 2011, .gov.au/earth-monitoring/geodesy/geodetic-datums/about.html
PRS92 website

13. Salamat

15. Relationship of Geoid and Ellipsoid
Earth’s Surface
Ellipsoid= h
Geoid= H
N = separation between ellipsoid and Geoid
Determined by measurement or by modeling N N N N N
h = H + N

16. Local Datum WGS84 Geoid Ellipsoid fitting North America & Philippines
Ellipsoid fitting Europe
WGS84
Geoid
Local Datum: Ellipsoid that best fits the project area.

17. GPS Coordinate System GPS uses WGS 84 ellipsoid
a= 6,378,137m; b=6,356, m
f= 1/
Geocentric Datum
Cartesian coordinate system is the system used by GPS in defining the location of a point in space. It use distances in the X,Y and Z axes from the origin (center of ellipsoid)

18. The PRS92 Program Components Geodetic Network Development18
The PRS92 Program
Components
Geodetic Network Development
Transformation and Map Integration
National and Regional Geodetic Network Information Systems
Support Activities

19. Geodetic Network Development (GND)
Continued the densification of the PRS92 network.
1st Order
2nd Order
3rd & 4th Order – 15,915

20. Data Transformation and Integration (DTI)

21. Data Transformation and Integration (DTI)
DATA CONVERTION
PREPARATION OF UNIFIED PROJECTION MAPS

22. National and Regional Geodetic Network Information Systems (GNIS)