PROPERTY SURVEY

• To which datum shall the coordinates of reference points be referred?

  PRS92
• Position of Surveys

  The complete horizontal position of reference points shall be expressed in latitude and longitude and rectangular grid coordinates, known as Geographic and Plane Coordinates (GPC)
• RECTANGULAR GRID = NORTHING AND EASTING
• DATUM

  The level surface, which is at every point perpendicular to the direction of the gravity.
• HORIZONTAL DATUM

  – USED AS REFERENCE FOR THE POSITION O THE EARTH’S SURFACE
• VERTICAL DATUM – ELEVATION DATA
• HORIZONTAL DATUM

  Luzon 1911 Datum

  Located at Station Balanacan in Marinduque Province

  Coordinates:

  Longitude N 13-33-41

  Latitude E 121-51-03
• VERTICAL DATUM

  PRS 92 DATUM

  Clarke Spheroid 1866

  Geoid Spheroid Separation: 0.34m

  Coordinates:

  Longitude N 13-33-41

  Latitude E 121-51-03
• Clarke 1866 spheroid

  semimajor axis- 6,378,206.4 m

  semiminor axis- 6,356,583.8 m
• COORDINATE SYSTEM

  • shall be the mathematical system of locating positions based on the standard datum and GPC
• LOCAL PLANE COORDINATE SYSTEM

  AKA FLOATING REFERENCE SYSTEM

  • The surveys are referred to location monuments with no define geodetic positions and subsequent adjustment to the basic geodetic control network.
• Reference points are established as the NEED ARISES, PER SURVEY PROJECT (public land subdivision, Group Settlement, Townsites) or per locality or municipality, wherein the relative position among the control points within the same system can be determined.
• PHILIPPINE PLANE COORDINATE SYSTEM(PPCS)/ LUZON 1911

  • transformed from geographic to grid coordinates on the Luzon 1911 Datum, determined through astronomical Observations.
• PHILIPPINE TRAVERSE MERCATOR (PTM)

  • Adopted as the coordinate system in the Philippine with the following characteristics

  Point of origin: intersection of the equator and the central meridian of each zone, with northing of 0 meters and easting of 500,000m
• PHILIPPINE REFERENCE SYSTEM 1992 (PRS 92)

  • shall refer to the modified Luzon 1911 Datum which was adopted as the datum for PRS92.
  • shall be the sole datum to be used in all surveys and mapping in the country.
• PRS 92

  • National network of Geodetic Control Points(GPC's)
• PRS 92

  • implemented in 1989-1992 through an Australian- assisted project- Natural Resources Management and Development Project (NDRMDP)
• PHILIPPINE TRIANGULATION NETWORK

  • established 1901-1911 by the US coast and geodetic survey
  • old geodetic data set had large errors up to 56m in latitude and 80m in longitude
  • narrow chains on 2nd order triangulation stations which has 4 origins.
• A new network was established using GPS, then called it the Geodetic Network of the Philippines
• What is the flattening of Luzon 1911 Datum

  1/294.978

  geoid separation is 0(zero)
• what is the inverse flattening of geocentric datum of Australia

  298.257

  
  

  semi major axis

  6378137.0m

  
  

  reference ellipsoid:

  GRS 1980
• 1st order: 10 parts per million

  1cm/km or 1:100 000

  2nd order: 20 parts per million

  2cm/km or 1:50 000

  3rd order: 50 parts per million

  1:20 000

  4th order: 100 parts per million

  1:10 000