We had a long discussion of this when NGS talked about it in a webinar.

https://surveyorconnect.com/community/gnss-geodesy/ngs-webinar-apr-25-on-the-fate-of-the-us-survey-foot/

Yes, I know Bill.?ÿ They seem to have made a final decision on its fate per the June 7 announcement.

I dunno boys, I see this as another "fix'n something that ain't broke."

I'll bet even money that in the short term (next decade or so), it will CAUSE more problems that it will solve. Those folks who have problems with 2 definitions of the "foot," will continue to have problems with the OLD Foot and the NEW Foot.

"In theory, theory and practice are the same thing. In practice, they ain't."

Yogi Berra

The single definition moving forward is a good idea. It will be interesting to see if Congress steps in to remind NIST and NGS that federal agencies cannot mandate any imperial units...

Posted by: Loyal

I dunno boys, I see this as another "fix'n something that ain't broke."

I'll bet even money that in the short term (next decade or so), it will CAUSE more problems that it will solve. Those folks who have problems with 2 definitions of the "foot," will continue to have problems with the OLD Foot and the NEW Foot.

"In theory, theory and practice are the same thing. In practice, they ain't."

Yogi Berra

Change is hard, but progress cant be made without it, but this is half hearted, if we are going to change the unit of measument used for surveying in most states, we should go all the way and use the meter, like the rest of the world.?ÿ

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Posted by: Loyal

I dunno boys, I see this as another "fix'n something that ain't broke."

I'll bet even money that in the short term (next decade or so), it will CAUSE more problems that it will solve. Those folks who have problems with 2 definitions of the "foot," will continue to have problems with the OLD Foot and the NEW Foot.

"In theory, theory and practice are the same thing. In practice, they ain't."

Yogi Berra

Change is hard, but progress cant be made without it, but this is half hearted, if we are going to change the unit of measument used for surveying in most states, we should go all the way and use the meter, like the rest of the world. Converting to the meter would be less confusing than changing feet becasue it is usually immediately obvious whether a a measument or coordinate is in feet or meters.?ÿ

Gene Kooper; Just where did you find the statement you posted? I have been trying to keep

up with this but I can't find what you posted.

I will give you a heads-up on a correction coming to "Procedures for Design and

Modification of the State Plane Coordinate System of 2022". As I said under a post

of MathTeacher on page 10 of the above publication under 6.b.i last two lines their value of

1/f to 18 significant digits is WRONG. They have 1/f = 298.257 222 100 882 744 and the

last 2 digits , (44) should be 11

?ÿ

JOHN NOLTON

I don't know the history of the two feet but it sounds dumb to begin with.?ÿ Abolish the international foot and let the rest of the world use metric, imo.

Gonna write to my Congresspeople. You surveyors are makin' the foot smaller to steal 2 million parts of my land.

The British imperial yard kept changing so they switched to the meter in the 1890s defining the meter as 39.37 inches long (an endless decimal fraction), tables were released to 4 places essentially making the foot 30.48 centimeters long which is not quite accurate over long distances. In the early 20th century machinists wanted an exact decimal definition so they changed the foot to exactly 30.48 centimeters long. It took decades for the new definition to become accepted. In 1959 the definitions were named US Survey Foot (original) and International Foot (new). They were supposed to drop the Survey foot in 1983 but left it up to the states.

Since the U.S. is the last place using the foot use the U.S. foot here, let the international foot die off.?ÿ

?ÿ

?ÿ

John, I have an old pencil note that I made at some time in the past that shows those digits to be ...2711243. I have no idea how I came up with that, but it does agree with your number.

But, if you use Moritz's formula for the semi-minor axis, b, and the first eccentricity squared in the SPCS2022 Procedures manual, and do the calculation in one formula: 

6378137/(6378137-6378137*sqrt(1-0.006694380022903415))

you get:

298.2572221008827446954301785592384680431647522357664846283...

from Wolfram Alpha:  https://www.wolframalpha.com 

Lots of things affect those end digits, including intermediate results and significant digits in the input.

Pages 12 and 13 of Stem's manual 5 describe the problems with the geometry of the GRS 80 ellipsoid.

Those of you that argue in favor of the US Foot do so because you don't want to change. If the US foot was made universal, I would have to change. The International foot is already in use in in several states. So somebody - many somebodies - are going to have to change either way. So that argument is a wash.

The conversion factor meters-US feet is a non-terminations decimal (or a fraction of 8 digits). The conversion meters-Int'l Feet is a terminating 4 digit fraction. Win Int'l feet, ease of use.

I'm in favor of a single, unified, definition. I think that just clearly makes sense. If the US foot is chosen for this use, the Int'l foot won't go away. Win for Int'l foot.

I'd like to hear your argument in favor of the US foot that doesn't boil down to "I fear change".?ÿ ?ÿ?ÿ

?ÿ?ÿ

I concur with the assessment, but disagree the change is a wash. The number of States using ift is a distinct minority. The case still stands on the merits...

I see these changes and end of support as an influence from the manufacturing industry that they have changed their standards and are not going to keep all units in the toolbox in active status and requiring upgrades all around the horn.

Progress does not always mean things will be better.

0.02

Here's the link, John.

https://www.ngs.noaa.gov/web/news/measure-unit-change-coming.shtml

I can't for the life of me understand why they would want to change it and not finally match the rest of the world using the meter.?ÿ

I remain neutral on this and whatever will be done to state plane coordinates in 2022.?ÿ I'm probably less than neutral because I don't care what is finally decided.?ÿ All I need are clear definitions and descriptions of what was done.?ÿ For mineral surveys, the original surveys were referenced to "true north" (usually based on a solar) and distances were measured with steel tapes that varied in length from 100 ft. to 500 ft.?ÿ

It is easier to keep my geodetic-based survey work in a coordinate system that matches the original work so I usually create custom, low distortion projections.?ÿ This allows me to directly compare my measurements to the mineral surveyor's measurements.?ÿ When I'm all done and someone requires my survey in a "standard" 2022 projection, datum and units, I transform my drawing with the press of a button.

I don't care what the NGS or NIST do.?ÿ As long as it is well documented (a given with the NGS), I'm good!?ÿ ?????ÿ

When the 2022 datum comes out, I'll likely conduct a bunch of tests to see what the error magnitudes are for a variety of blunders that an incurious surveyor will most assuredly make.?ÿ With that, I'll have a good idea of their blunder when their coordinates don't match mine.

Posted by: TNRLS

I can't for the life of me understand why they would want to change it and not finally match the rest of the world using the meter.?ÿ

My feelings exactly, the USC&GS/NGS has been using meters for a long time, and NAD83 was originally going to be a metric system. I don't see any value in the NGS getting into the "land survey" business. Let the States decide which unit works the best for them, and IF the several States want to use the US Foot, International Foot, Chain, Link, Rod, Pole, Perch, Cubit, Vara, Arpent, or Smoot, then FINE! Who Cares?

Loyal