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Oregon Coordinate Reference System

Picture of MapThe 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.

OCRS Handbook and User Guide

OCRS Map Overview



OCRS_Current.CSD - This for Trimble's Coordinate System Manager program; see the README file for instructions.

Use this link to access the Geometronics Tool Kit.

There are two components of the Geometronics Online Toolkit:

The Oregon Coordinate Reference System component of the online toolkit allows users to determine the best low-distortion projection zone for their project. Users can display all of the OCRS zones on a map. They can also view the actual distortion of a particular OCRS zone near their project by placing a point, line or polygon on the map.

The Oregon Real-time GPS Network component of the online toolkit allows users to view the status of ORGN sites, view a map of coverage areas in Oregon where real-time GNSS correctors from the ORGN are available, and display or download a list of ORGN stations with the current coordinates for each station and a link to the particular website for each station.

Additional Information

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.
  • Can cover entire cities and counties, making them GIS-friendly.

Modern geographic information systems and surveying software now bring the opportunity to create low distortion map projections and coordinate systems that can relate closely to measure distances on the ground.

The function of low distortion projections is to minimize the distortions of angles, azimuths, distances, and areas. These distortions are present as we live on a spheroid.

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.​

Contact the Geometronics Unit

800 Airport Road SE
Salem, Oregon 97301
Phone: 503-986-3103
Fax: 503-986-3548

Program Lead

Phone: 881-2889

Resources and Related Content


Geodetic Control and Benchmarks