Supported Coordinate Reference Systems

There are two common types of coordinate reference systems (CRS) used in engineering:

  • A geographical coordinate reference system uses latitude–longitude coordinates to map the earth’s spherical surface. More information on geographic coordinate reference systems is provided here.
  • A projected coordinate reference system uses X-Y coordinates (commonly called Northing and Easting) to project maps of the earth’s spherical surface onto a two-dimensional Cartesian coordinate plane. More information on projected coordinate reference systems is provided here.

Since HEC‑RAS utilizes X-Y coordinates for defining elements of the river system, only projected coordinate reference systems can be used. However, GeoHECRAS will automatically reproject data sets that use geographical coordinate reference systems to the assigned Map View projected coordinate reference system if the data lies within the projected CRS bounds.

About the Author Chris Maeder

Chris Maeder

Chris is an experienced civil engineering and software technology leader, with over 30 years industry experience. With proven expertise in global software development, he has built engineering teams that adapt quickly, focus on what’s important and, most importantly, deliver. He is a licensed professional civil engineer with extensive experience in water resource engineering. He has performed and supervised engineering projects in urban stormwater drainage, transportation and roadway drainage, storm sewer design, detention pond design, stormwater quality, green infrastructure, watershed management planning, wastewater sewers, water distribution networks, pump stations, FEMA flood studies, bridge and culvert design, bridge scour and armoring, dam failure analysis, seepage and groundwater modeling, and environmental permits.

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