Managing Datum Change: Project Coordination and Risk-Managing Datum Change: Project Coordination and Risk Recording

Video Transcription

Video Summary

The session introduced upcoming modernization of the National Spatial Reference System (NSRS), including new datums that will replace NAD 83 and NAVD 88. Presenters from NOAA/NGS and ACEC explained that the changes are driven by tectonic plate motion, improved knowledge of the earth’s center, and the need for a more accurate, time-dependent, globally compatible reference system.<br /><br />Key points included the concept of “shift and drift”: a one-time coordinate shift when the new system is adopted, followed by ongoing motion modeled through epochs. Coordinates in the modernized NSRS will always include a date/epoch, with reference epoch 2020.00 being the starting point. The new State Plane Coordinate System of 2022 (SPCS 2022) will have many more zones, designed to reduce distortion and better support engineering and surveying workflows.<br /><br />Speakers emphasized that nearly all geospatial data and software could be affected, especially systems used for surveying, mapping, elevation, flood modeling, transportation, and digital twins. They urged firms to begin preparing now by reviewing metadata, accuracy requirements, workflows, and vendor support. Three paths into the new system were highlighted: resurveying, readjusting existing observations, or transforming data with NGS tools like NCAT.<br /><br />The panel also discussed backward compatibility, the U.S. survey foot’s phase-out in favor of the international foot for SPCS 2022, and the importance of documenting datum and epoch in deliverables. Beta tools and resources are already available, with final rollout expected around 2027.

Keywords

National Spatial Reference System

NSRS modernization

NAD 83

NAVD 88

NOAA NGS

tectonic plate motion

time-dependent coordinates

epoch 2020.00

State Plane Coordinate System 2022

SPCS 2022

geospatial data

surveying workflows

NCAT