How many of you were aware that our beloved US Survey Foot is being retired? How many even knew there was a US Survey Foot that differs from the International Foot? The US Survey Foot is the primary unit used by many State Plane Coordinate Systems. At the beginning of this year, the National Institute of Standards and Technology (NIST) depreciated the US Survey Foot and deemed it as obsolete.
This is just the first of many changes coming in the not-so-distant future. As many of you are also aware, a new datum is coming very soon to replace the multitude of NAD 1983 datums we have been using with most State Plane Coordinate systems. This move to retire the US Survey Foot is part of that same modernization of the National Spatial Reference System (NSRS) by the National Geodetic Survey (NGS). This means that all State Plane coordinate systems will be redefined using the new datum and be based on the International Foot.
Don’t panic just yet and start trying to reproject your data. This change and redefinition has been delayed. Originally it was supposed to happen in 2022. The implementation of newly defined coordinate systems based on these new components is not expected to happen until at least 2025. So for now, you can continue to use your NAD 83 State Plane Coordinate System in US Survey Feet. Just keep in mind that at some point that will need to change. If you want to learn a bit more click here for an article from the State Cartographer’s Office from the University of Wisconsin-Madison.
Tripp Corbin, MCP, GISP
Business Development Manager – GIS & Aerial
SAM, LLC
470-998-8944 (Cell)
Tcorbin@sam.biz
2/28/2023