Changes Afoot After 2022: State Plane and the Death of the U.S. Survey Foot
Tuesday, October 6, 2020 - 1:00 - 4:00 PM
Instructor(s):
Michael Dennis, Ph.D., PE, RLS, Geodesist/SPCS2022 Project Manager, NOAA's National Geodetic Survey, Vail, AZChange is coming. People often don’t like it, but some changes are needed to make the world a better place. This presentation is about changes that are nearly upon us: in 2022 or soon after, NOAA’s National Geodetic Survey (NGS) will modernize the National Spatial Reference System (NSRS). Since the NSRS is the basis for civilian positioning in the U.S., modernizing it will profoundly affect GIS and other geospatial professions. Among the changes is replacing the existing State Plane Coordinate System of 1983 (SPCS 83) with SPCS2022. Key changes and innovations will be described, with an emphasis on the NGS zone design process and the use of zone “layers” for SPCS2022. An update will also be provided on the status of SPCS2022, including the use of low distortion projection zones designed by state stakeholders. But that’s not all. The end of 2022 will also see the end of the U.S. survey foot and its nationwide replacement by a single foot definition (identical to the international foot). The story will be told of how we ended up with a dual foot definition, its connection to State Plane, and the problems it caused—all leading to the inescapable conclusion that the U.S. survey foot must die. Safety is not guaranteed.
Learning Objective 1: Learn how the State Plane Coordinate System will change after 2022, why those changes are being made, and how they will be implemented. Includes learning about projection linear distortion and showing how different SPCS2022 zone layers can be used for different applications, from GIS analysis to surveying and engineering design.
Learning Objective 2: Learn the history of the foot in the U.S., find out why the definition changed, the problems caused by using two-foot definitions at the same time, and the solution after 2022.
Case Studies: Examples will be shown of actual new SPCS2022 zones and how they exist as layers, from statewide zones to local low distortion projections, and how they differ from existing State Plane. Examples will also be given of confusion and errors that have occurred by accidentally mixing the two-foot types (yes, that happens, a lot).
Skills: Attendees will leave this presentation with a clear picture of how State Plane will change after 2022—and how it will not change. They will know when and how to choose a particular State Plane zone layer for their applications, and they will gain an understanding of what conformal projections are and why they are used. They will also gain insight into recognizing and avoiding problems caused by accidentally mixing of foot types.
