OPUS and US feet

I thought you just needed to multiply meters by the 3.xxxx factor, as the origin and false E and N values apply regardless of the final units.

Take an older OPUS report and check that this works.?ÿ

...off point a bit, Recent History:
people were getting very confused with the differences between International Feet and US Survey Feet, they used the Wrong Foot and fubared it all over the place. So the Bureaucrats up above decided to dumb it down "to eliminate confusion".?ÿ This was despite the numerous objections from the Land Surveyor in a dozen or more States are on US Survey Feet for their State Plane Grid Systems.

I understood the decision was to eliminate publishing US Feet and instead just publish Meters (the native vale) and the conversion to International Feet.
I predicted that those same confused people would just jump on the International Foot values and make a royal mess of things.

This new OPUS output with Metric Only is great news! Now it is just math to convert to the preferred/mandated flavor of Feet.

Posted by: @peter-ehlert

This new OPUS output with Metric Only is great news!

Agree. I'm 99% sure geodetic computations for all software programs are done natively in meters. Ever bluebooked anything? NGS will reject anything other than meters.

Posted by: @bigd1320

Does anyone have a tool or website that will get me from meters to US feet in IA North? I was using the conversion for meter to US feet, but I must be missing something. (1 US ft = 1200/3739m)

That's the conversion to use (IA is USFt, not IFt, IIRC).

If you really want to hand-enter the geodetic values in an online tool, NCAT's got you covered in the feet conversion.

?ÿ

3.2808333?

As Rover83 said - NCAT.

@peter-ehlert?ÿ ?ÿ'flavor of foot', really?

The tool I use is a calculator. For software I might employ Excel.

I found what I was looking for. NCAT results are in meters and US feet. The results match the NRTK 5 epoch shots I took earlier this week. The horizontal was within 0.04'.

?ÿ

Thank for the replies. I enjoy communicating with other surveyors.?ÿ

Dan

OPUS is unchanged.

For local units, select upload Options > Format > Extended report, and then look waaaaay down near the bottom of the solution. Just as always.

OPUS finds the state-chosen foot (for states which have chosen) from SPCS table.

Now that NGS has NCAT, itƒ??s tempting for OPUS to simply generate ITRF-frame ECEF XYZ plus accuracies at survey epoch, then throw the user into NCAT to dial in their own frames, datums, projected coordinate systems, units, epochs, etc.

The OPUS report format ?ÿis ancient and unchanged, but due for an update, either from the upgrade to the processing engine (2021) or NAD83 replacement (2022). Via what forum can the community suggest which OPUS features to keep and which to add? Send ideas to NGS.opus@noaa.gov and or attend the OPUS User Forum on Tuesday https://www.ngs.noaa.gov/web/science_edu/webinar_series/special-opus-user-forum.shtml

?ÿ

@bigd1320

You have a transposed digit in your conversion formula. 3739 should be 3937.?ÿ

Actually, it's a double transposition. Back in the early days of my numerical life, we considered people who made double transpositions to be exceptionally talented.?ÿ

Congratulations!!

Posted by: @mathteacher

Good eye!?ÿ I should have caught that.

I've never paid any attention to the xy from an OPUS report. The lat long is all I care about.?ÿ

@oldpacer

Tasty feet. Yum.

Really? You need a website to convert from meters to US FT?

@joegeodesist

Joe: NCAT does NOT support ITRF, which, in my opinion, is a serious mistake. I have been complaining to whoever will listen at NGS that NCAT needs to be able to access the HTDP model. Maybe you can help push for it...?ÿ?ÿ

When you originally input your data into OPUS, instead of standard report, select Extended report and at the bottom of the 5 or so page report you get back, you'll see the SP Coordinates in U.S Feet