International Feet vs. US Feet measurements

[Craig_Eissler_Iceman]

There seems to be several terms used to describe measurements in units of feet.

Is the "matching" chart below correct with respect to Int'l vs. U.S.?

"Imperial is the one that confuses me the most, because i read that the U.S. is the only country still using it. If so, why do we also have US Feet?

Thanks,

[AyanPalit · Accepted solution]

The following table should help:

International foot	US survey foot
Imperial foot	US foot
Foot	Survey foot

Note that, ArcGIS Pro didn’t differentiate between the two distinct foot definitions previously and this was updated in ArcGIS Pro 3.0. 

As in the NOAA publication referenced: 

"U.S. survey foot is retired and replaced by international foot."

"From this point forward, surveyors will refer to the international foot as simply the foot."

[Craig_Eissler_Iceman]

Thanks, but then why is ArcGIS now recognizing these terms/measurements that are retired.

...It seems "opposite", unless I'm still not understanding

[AndrewLeason · Accepted solution]

Those terms have been in ArcGIS for years. However, if we now remove them then data that people have been using in those units will suddenly stop working, which would be a problem for a lot of users. 

[Craig_Eissler_Iceman]

Understood. Your initial Reply indicating some of those had been "retired" is part of what confused me because I still see them in ArcGIS. ...But, now I know what you mean. Thanks,

[GerardAshton]

I won't comment on how things work within ESRI products. The National Geodetic Survey (NGS) hosted a webinar on the new State Plane Coordinate System 2022 November 10, 2022. They made available a PowerPoint of the slides from the webinar.  Slide 47 of that PowerPoint shows that, officially, Texas uses the survey foot for the Texas State Plane Coordinate System of 1983. Pretty much all the official announcements say that the survey foot may continue to be used for legacy applications, and if you browse through the NGS PowerPoint or look at the other webinar resources, you will see that SPCS 83 is considered a legacy application and survey foot will continue to be supported, in the states that chose it, permanently. In those states, when using an SPCS, the foot change will occur project by project as each project switches to SPCS 22, or new projects are started in SPCS 22. It's expected SPCS 22 will be available mid-2025.

[AyanPalit]

@GerardAshton Thanks for the comments. 

A recent blog posting related to the National Spatial Reference System (NSRS) modernization:

Prepare your data for the National Spatial Reference System modernization of 2022 in the U.S.

Additional notes on Using Foot as Linear Measure Units