About 25?ñ yrs ago, at the beginning of TxDot's change to metric, I found myself in Wood County along Hwy 49 at the bridge crossing on Lake Fork Creek between Hainesville and Mineola.
A small caravan of TxDot vehicles pulled over ahead of us and started pulling out boxes and started unpacking all new surveying equipment.
Had to check all this out and turned out to be their new metric rods and long and short tapes of metal and cloth.
They were beginning a bridge widening survey and spent the day using the metric tapes to look for their control that was in feet.
A most unhappy survey crew for sure as their conversions were not fitting properly.
I found two highway control points on the other side of the road from where they were looking and they were very happy for that.
Set up, tied those in and measured some distances with the TS to rods set at fence corners in the distance and packed up and they were still working it out.
The decision did not last long and TxDot canned all the metric and stuck with feet.......
I am going to have to check because I do not know if my newest TS has an international feet setting.
It will allow for a constant to compute most any conversion.
The thought of updating all my past data and all the recorded data into that form is going to give me some real thoughts of finding another path.
While the Federal government has the authority to establish standard weights and measures, and it has the power to ensure that people adhere to those standards. It has no authority to dictate ( outside of federally funded/controlled projects) what unit of measure
any individual or group prefers to use.
If, hypothetically, NGS only provided coordinates in meters, there is no reason that day to day work would also need to be reported in meters. It just means that users would need to convert the data from NGS from meters to whatever flavor of feet they prefer (or is required).
You will never see the difference in international feet and US Survey feet in a total station. It's only 2ppm different (0.002 per 1000).
My deep sarcasm to change comes from working with a mentor that taught me how to use a solar compass to retrace original Headright boundaries across East Texas.
It was so simple and has proven to be an everlasting method that most resembles following in the original footsteps.
Change is always happening and to me will never replace the satisfsction of opersting the original equipment.
Techno babble can never replace the ability to read a spot and recover the monuments that control while science continues to refine where it's location is according to today"s location when according to esrth's ever changing grad scale of change will eventually be found to have apparently moved 0.04ft.
First, change in inevitable. before 1900 most people had never been more that a hundred miles from their home. Now I don't think twice about jumping on a plane and fly to a job. I could use a compass and chain for all of my projects but prefer to use the total station and GNSS. Your statement prove the point, those before us changed from the chain or var to the foot. I'm sure some made the same case.
As for grid bearing and ground distances, it is simple math. Scale points by the same factor and their angular relationship remains the same.
"I think that NGS and Surveyors should .... stay with the US Survey Foot"
And ignore that 6 states are using the International Foot now. Somebody is going to have to change.
Yes, there's a lot of world data, usually rasters, that uses 0-360. Occasionally you'll get -360 to 0 data.
To an outsider, it just seems a bit strange. Weather forecasting and climate models already have a substantial number of ways to convert data from -180, +180 to 360 and back again.
i can see reasons for your objections.
Shawn Billings, I would take exception to your statement above about not seeing the difference between the international foot and
the US Survey foot IN A TOTAL STATION. You don't state what you would call a TS and you don't give a minimum to a maximum
distance. The Leica AT401,402 and the 403 which are laser trackers measure both horizontal and vertical angles plus they
measure distance way less than 2ppm. The short side is they only go to about 40 metre. I would call these Leica laser trackers a TS.
JOHN NOLTON
"Techno babble can never replace the ability to read a spot and recover the monuments ..."
It is reasonable to expect a Professional Surveyor to both find the right monument and comprehend modern positioning technology. It's only babble if you don't have the language.
Another way to express the difference between US Feet and Int'l Feet is 3mm per mile, or about 0.01'.
2 ppm in 40 meters is 0.08mm. That's metrology territory.
NGS or NIST could go to Congress with such a request. When only a minority of states using the falsely labeled International foot, what do you think the result will be? Dennis can think the foot will creep back in eventually, but it doesn't have to. Years ago NGS published the decision to report only in SI units. They should stick with that decision and leave the rest alone.
Yes, NGS should stick to it's lane.
I'm switching to British Imperial Furlongs.
The meters dont change, just how you Express meters in terms of feet. We are already using meters in the background.
If you measure 1 mile in US Survey Feet you get 1609.347m. If you measure a mile in Int'l Feet you get 1609.344m. The meters don't change, the mile does.
Or should I say that 1 international mile equals 5279.989 US Survey Feet?
yeah, I had a brain fart when I typed the fraction. I use the fraction you stated to convert back and forth.
LOL! Discover Magazine is on board with NGS, but maybe a bit misinformed. Have to go down to number 19, but here's their take:
http://discovermagazine.com/2019/jun/20-things-you-didnt-know-about--feet
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I see an opportunity here to expand California into Oregon, Nevada, and Arizona here.
The US Survey Foot is defined as a perfectly good fraction, 1 USFt = 1200/3937 meters, not as they incorrectly express it. The digitalists insisted that it be 3084/10000 meters instead or 771/2500 meters if you prefer.
