This is actually an argument against the US Survey Foot. It is actually a survey inch - being it defines itself in terms of inches per meter.
Perhaps. It was the yard that was defined in terms of the meter, 1 yard = 0.9144 meters. Value for inch was then derived from the value of the yard, 0.9144/36 = 0.0254. So the inch is defined in terms of the yard, which is defined in terms of the meter. I'm not sure as to whether the foot is defined in terms of the inch or in terms of the yard. Either way, it's 0.3048 meters. Here's the NIST FAQ:
https://www.nist.gov/pml/weights-and-measures/si-units-length
Hairsplitting aside, I think that the Discover piece argues for all metric, albeit it subtly. It was the cavalier dismissal of the survey foot that caught my attention.
The definition of the foot resides in 49CFR 171.10. A bit if research is likely to disappoint advocates on both sides.
The unit of measure for distance is the meter. The foot is defined but only in an advisory capacity. NIST lacks congressional authority to define the foot. If they intend to change the CFR thry will need to run the legislation first. Normally this would be simple. I'll refrain from dragging this into P&R territory..
FWIW I agree with NGS, just go to a single definition of the foot and it is best to use the international foot definition.
It's trivial in an operational sense, but the definition of the yard was by international agreement. 49CFR 171.10 codifies that definition.
The conversion factors in 49CFR 171.10 are not definitions. They are derived from the definition of the yard in terms of the meter.
But there's no telling what might come out of congress if this ever gets to a vote.
... They are derived from the definition of the yard in terms of the meter.
But there's no telling what might come out of congress if this ever gets to a vote.
Probably come up with?ÿ 1 yard being equal to 3.000006000012?ÿ feet!
In the legsl sense this is where they are defined by adminustrative law, hence the term 'definition'.
Comgress generally sets basic framework and grants the agency authority to define things by rule. In this case congress told NIST to go metric. I doubt they will change that.
Agreed. What is it now, 60 years and how many lines of computer code since the dual system came into being? And the legacy data will be a problem forever, but that's true now for chains, rods, etc.
On the other hand, data sheet coordinates are going to change anyway, so perhaps now is a good time to change the foot if it needs changing. Maybe rely on NGS' coordinate conversion tool for backward compatibility.
If it's changed, though, one of the most valuable people in a survey foot state is going to be a surveyor who knows the difference between the two from experience; someone who knows to ask the question when legacy data is referenced.
It's not the distances, it's the coordinates, and keeping them unmixed will be a problem in this unwashed amateur's opinion.
data sheet coordinates are going to change anyway, so perhaps now is a good time to change the foot if it needs changing... It's not the distances, it's the coordinates
Those are the key points.?ÿ If you have old coordinates you have to do a translation to new ones regardless of which foot they are in, and once you get into the neighborhood you won't see the trivial differences in lengths.
I am in the meters camp. NGS could avoid a lot of pain if they simply followed the law and stopped publishing anything in feet.
The various types of feet will always exist. Making a mandate that encourages vendors to pick one and delete the others is a bad idea. We will then be at the mercy of a government that can't even keep its own doors open in any reliable manner...
As long as odometers are in miles, the highway people will need feet ????.
As I said at the beginning of this thread, I just don't see any real value in the NGS tilting at this particular windmill. The "standard" OPUS Report is entirely in Meters, and only the "extended" Report contains any "feet."
Current NGS Data Sheets contain various items in both Meters and "feet" (US or International depending on the State), BUT ALL of the information in "feet" is still BASED on the Metric Value.
Regardless of the eventual outcome of this "issue," the underlying UNIT of all of the Geodetic, and geodetic based data, will still be in meters anyway, so what's the point in stirring poop at this point.
Just my 2-bits,
Loyal
Just want to mention: NCAT does output feet in SPCS, both International and US.