GIS Design Support for NSRS 2022 and Low Distortion Projection Zones

513
2
10-25-2018 12:14 PM
Status: Open
Labels (1)

When the new Horizontal Datums are released, states will be making choices about datums and projections.  These choices will have impacts on the GIS community as well as Surveying, Design, and construction industries.  

 

Some states will define statewide projection zones, and many states are defining low distortion projections.  It will benefit communities creating and stewarding GIS data to define projections minimizing distortion, thereby making GIS data more valuable for surveyors, designers, and builders.  

 

Changes in GIS are occurring nationally, with directives and objectives to "roll up" community developed data to state and federal levels.  

 

With the current design, a State would likely need to project from a community level Low Distortion to a conformal statewide projection to take advantage of data defined in a projection.  Likewise, the feds would have to define their projection on a US level.  Each re-projection to a larger area will introduce distortion.  

 

The idea is to architect the ArcGIS platform and the Geodatabase/feature dataset containers to allow feature data to remain in the low distortion projections.  Applications would then need to be able to cluster these geodatabase projection containers together for processing and spatial analysis in desktop software in a hive like distributed system.  Enterprise level servers would need to be able to combine the clusters into a seamless application service with many defined source projections.  Ideally enterprise applications would display maps using NSRS projections on the fly based on scale level.  AND this approach needs to work with Linear Referencing systems including Roads and Highways.

2 Comments
KoryKramer
KyleGonterwitz

Good article, there is a lot of material out there on the web to read on this topic.  

It comes down to this: creators of GIS data at the local level create data in a projection.  Cartographers use a projection.  Surveyors use a coordinate system.   Hopefully, the cartographic projection and the surveyors coordinate systems are based on a similarly defined datum.  The common datum should support the accurate measurement coordinate system, and a multitude of projections appropriate for the cartographic needs based on the extent of the earth displayed in the map.  

With definition of low distortion projection systems in the GRAV-D datum, surveyors and mappers can work together in the same projection as a coordinate system.  As a state practitioner of GIS involved in engineering and construction, I am attracted to the idea of maintaining a shape-length-based linear referencing system of highways (or other linear networks) defined in the multiple (20) low distortion projection systems in my state, and rolling them up into the ArcGIS applications (desktop, web based, etc) seamlessly. 

In other words, I would like to be able to print my statewide map in my statewide conformal projection (eat my cake), while keeping my data defined in the 20 separate low distortion projections (have it too) in order to maintain the most accurate shape length definition at the topographic surface.  I'd like the software do this for me out of the box without having to develop this solution myself.