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Oregon Coordinate Reference System

About the 'OCRS'

 
The Oregon Coordinate Reference System is based on a group of low distortion map projection coordinate systems. Low distortion projections are based on true conformal map projections designed to cover significant portions of urban and rural areas of the state.  The term ‘low distortion’ refers to both the horizontal distortion from presenting a curved surface on a plane and the vertical distortion because these projections are also scaled to a regional height representative of the area to be covered.  The advantages of a low distortion projection are; 
  • Grid coordinate zone distances closely match the same distance measured on the ground.
  • Limited distortion and reduced convergence angle.
  • Easy to transform between other coordinate zone systems.
  • Maintains a relationship to the National Spatial Reference System (NSRS).
    Can cover entire cities and counties making them GIS friendly.

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History

 
The utilization of electronic survey data by surveyors and GIS professionals is bringing awareness of the need to better deal with measurements on the earth and their representation in databases and on paper.   Modern GIS and surveying software now brings the opportunity to create low distortion map projections and coordinate systems that can relate closely to measured distances on the ground.  The function of low distortion projections is to minimize the distortions of angles, azimuths, distances, and areas.  These distortions are ever present as we live on a spheroid and it is impossible to represent a curved surface on a plane.   We must account for that distortion by creating a mathematical model map projection that will allow us to work in a coordinate grid where calculated positions and distances are represented closely by the same positions and distances we measure on the ground.  For GIS professionals, low distortion projections may now demonstrate that ‘rubber-sheeting’ data sets to make things fit is no longer necessary.  Both survey and GIS data can co-exist without either dataset being degraded.

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Senate Bill 877 was enacted in Oregon in 2011 to  allow the use of the Oregon Coordinate Reference System or legacy State Plane Coordinates whenever the use of State Plane Coordinates was previously allowed.  Nothing in Senate Bill 877 requires the use of the Oregon Coordinate Reference System.

The Oregon Transportation Commission adopted new Oregon Administrative Rules (OARs) defining the Oregon Coordinate System (734-005-0005, 734-005-0010, 734-005-0015)  on December 21, 2011.  The rules were filed with the Secretary of State on December 22, 2011 and became effective on January 1, 2012.

These rules implement Senate Bill 877 by moving all definitions of the existing Oregon State Plane Coordinate System from ORS Chapter 93 to ODOT's administrative rules and also placing all definitions for the new Oregon Coordinate Reference System into the new OAR.
The new administrative rules concerning the OCRS are now listed on the Secretary of State's State Archives website under ODOT Highway Division, Chapter 34, Division 5 (Oregon Coordinate Systems).

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OCRS Zone Export (Parameters)

 
Leica LGO - TRFSET.DAT   [***NEW*** All 20 Zones]
Current.CSD - The current.csd is for Trimble's Coordinate System Manager program; see the README file for instructions.
 

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GIS Projection (.prj) Files

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OCRS Handbook & User Guide

 
Use this link to access the OCRS Handbook & User Guide.
 
 
 

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GIS Interactive Map Tool

 
Geometronics is currently developing an Interactive GIS map system that will provide users with a wealth of Coordinate Reference information.  The goal is to have the map available sometime this summer.  When the GIS Interactive Map Tool becomes available, a links will be provided in this section.
 
 

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Frequently Asked Questions

 
A link to an upcoming FAQ page will be provided in this section.
 
 

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