For the US, it is up to each state. Many still use the Survey foot, some have gone to the International foot since the release of new geodetic data to the NAD83 datum.
Anyway, I defy you to survey the difference which is 2 ppm. Long steel tapes, when corrected for temperature and at proper tension are certified to 0.02% (200 ppm). A little Googling turned up an Australian standard for EDM equipment, plus/minus 5 mm + 30 mm/km over length of baseline, so 35 ppm over a kilometer. Surveying simply doesn't have the precision to resolve the difference. The difference between International and Survey foot only matters in State Plane Coordinate Systems, where large false offsets are used to place the data in certain ranges for different zones in a state with multiple zones. It is really a calculation matter, not a measurement matter. As the false offsets may be millions of feet (and they are really calculated from data in meters by USGS), the wrong foot (0.3048 m or 1200/3937 m) can make a difference of a few "feet." (What really happens is that the false offset in meters is either multiplied by 1250/381 or 3937/1200.) These coordinates are theoretical anyway, as they are computed from lat/long, referred to the ellipsoid, not the geoid, then mapped to a Lambert conformal conic or UTM projection. ________________________________ From: Pat Naughtin <[email protected]> To: U.S. Metric Association <[email protected]> Sent: Sun, January 30, 2011 2:25:06 PM Subject: [USMA:49693] Re: [SI] A mole hill into Himalaya Dear Martin, In the second reference you provide, they say: … notable exceptions are the United States and the United Kingdom where the statute mile is used. Is this correct? I thought that the UK used the 1959 international mile, while the USA used the survey mile (that is also known as the statute mile). Cheers, Pat Naughtin Geelong, Australia On 2011/01/30, at 20:03 , Martin Vlietstra wrote: See http://en.wikipedia.org/wiki/Kilometres_per_hour and the last picture in >http://en.wikipedia.org/wiki/Kilometres for more about the universal use of >SI symbols. > >-----Original Message----- >From: [email protected] [mailto:[email protected]] On Behalf >Of [email protected] >Sent: 29 January 2011 21:27 >To: U.S. Metric Association >Subject: [USMA:49683] Re: [SI] A mole hill into Himalaya > >Agreed John, and non-US citizens may post in French, German, Spanish, >Italian, Portuguese, Esperanto, Commonwealth English, etc. or in any of the >other language that I did not list, so long as they are reasonably >respectful of the standard rules or accepted practices of that language, >whatever they are. > >However, all of us must remain aware that there is no such thing as >"universal or global English" with respect to spelling and grammar, only SI >(m, kg, s,...) is global!! > >Gene. > >---- Original message ---- > >Date: Sat, 29 Jan 2011 11:29:18 -0800 (PST) >> From: "John M. Steele" <[email protected]> > Subject: [USMA:49681] Re: [SI] A mole hill into Himalaya > To: "U.S. Metric Association" <[email protected]> > > Wait. I don't agree with that. I am fine with our > members from Commonwealth nations using Commonwealth > spellings in their posts. What I am tired of is > flogging the spelling issue. I do think the > Americans should use the recommended spelling of > NIST SP330 and US GPO Style Manual. > > If both spellings are acceptable, there is really > nothing to debate, is there? (he asks rhetorically) > > ------------------------------------------------ > > From: "[email protected]" <[email protected]> > To: U.S. Metric Association <[email protected]> > Sent: Sat, January 29, 2011 2:13:11 PM > Subject: [USMA:49680] Re: [SI] A mole hill into > Himalaya > Agreed! Let's drop the subject of spelling > *concurrent* with proper respect for > well established laws and practices in the USA which > *do not contradict SI*; which include USMA Web > Pages. > > Please cease and desist addressing messages to the > USMA which deviate from the official USA spellings > (US Government Printing Office) meter and liter. > > Gene. > ... > Pat Naughtin LCAMS Author of the ebook, Metrication Leaders Guide, see http://metricationmatters.com/MetricationLeadersGuideInfo.html Hear Pat speak at: http://www.youtube.com/watch?v=_lshRAPvPZY PO Box 305 Belmont 3216, Geelong, Australia Phone: 61 3 5241 2008 Metric system consultant, writer, and speaker, Pat Naughtin, has helped thousands of people and hundreds of companies upgrade to the modern metric system smoothly, quickly, and so economically that they now save thousands each year when buying, processing, or selling for their businesses. Pat provides services and resources for many different trades, crafts, and professions for commercial, industrial and government metrication leaders in Asia, Europe, and in the USA. Pat's clients include the Australian Government, Google, NASA, NIST, and the metric associations of Canada, the UK, and the USA. See http://www.metricationmatters.com/ to subscribe.
