Topic: Survey ft vs Intl ft

[mjfarrell]

Not being a surveyor.....Do I know the difference between a Link, and a Rood?  Yes.


Rood??  I know of links,inches, feet, yards, rods, miles, varas, chains, acres, hectares, poles, leagues, labors and perches, but "Rood" is a new one to me?

It's actually quite old, and I used to work in the field performing topographic as well as boundary survey duties.  I've also had several college level classes in Plane Surveying.

Am I a Surveyor?  No

Do I understand and consult with Surveyors on these matters?  Yes.

[BlackBox]

Does 'someone' like answering their own questions?  Yes.

  LoL

[Dent Cermak]

Rood....old english 1/4 acre. Hmm? A unit of area not a unit of measurement?
But if in your consultations with surveyors you are telling them that using International Feet on their work is just fine, you are doing a diservice that can get them sued.
True, all units being the same on a drawing is jusy fine.......UNTIL someone else goes to lay out the project on the ground using state plane control. Or when the State Board notes that the initial survey was performed using International Feet.
Best way to do a job is the right way the first time. By the book, by the state regs and as per standards.

[mjfarrell]

Rood....old english 1/4 acre. Hmm? A unit of area not a unit of measurement?
But if in your consultations with surveyors you are telling them that using International Feet on their work is just fine, you are doing a diservice that can get them sued.

Dent,

Please go back and notice I never advocated use of any particular unit of measure.

Point of fact the advice I give most often is to use State Plane coordinates.
With the exception that they should use the localized Low Distortion system if it is available.

Somehow the conversation went from "if my drawing is using a unit of measure how will I know?".
And twisted into; Higgs doesn't know his feet from his parsecs. And that simply isn't true nor the point of the discussion.

[Dent Cermak]

Is/Was   :ugly:

[sinc]

I'm wonderng why it would matter?
Given that the file was started in one unit or the other, what difference would it make, if you kept working in that same unit?

The big reason that it matters is that C3D does "automatic conversions" without warning you, if you have things set wrong.

This can be very problematic when multiple companies are involved, and one of them doesn't realize that they need to set their units to the right type of foot.  When doing LandXML import/export, you can end up with unwanted translations.

Another problem results when trying to work with people on Microstation.  I've gotten plan sets from the Army Corps that were converted from DGN to DWG, and some of the DWGs are converted using Survey Foot, while some are converted using International Foot.  All of these drawings are part of the same plan set, but something they do on the Microstation end of things can create different outcomes.  Combining two such mis-matched drawings results in linework that is offset, with one or the other being erroneous.

It's definitely important to know which foot you should be using, and to use it consistently.

[mjfarrell]

The conversion of DGN's to DWG's would not be an issue associated with the original question.
That was about how can I know what units my file is set up in?

And as others have pointed out, all members of the team need to know what unit the work will be done in.

I get that.  However I still can't see that as an issue; IF the file was set up on the correct units for the project from the start.

This isn't to be construed as " I don;t see units, or conversion between systems of measurement as an issue."
I do, and using NASA as an example also know that sometimes conversions are not done correctly and a
multimillion dollar space probe is lost in the process.

I'm back to the same place on this, IF the file was set up on the correct units for the project from the very start, how would knowing it's units be of any benefit?  Given one continued to work in the correct units.
Unless you are grabbing information from other files that might be on other systems.  In such instances it would
be suggested that one XREF the data in with a common origin to verify that the data was in the correct place in relation to the project PRIOR to actually attempting to import it into the working file.  And even if it was in the correct
location I would suggest it STILL remain in an XREF for other data management reasons.

[sinc]

I think your point may be too subtle for me to grasp...

However, I've dealt with "drawings from others" where the Foot type was set incorrectly.  We NEVER use International Feet in Colorado, yet I've gotten C3D drawings that were set to International Feet, basically because the person who created the drawing isn't very skilled at using Civil 3D.  I *know* this affected any LandXML transfers.  It seems like it also affected DREFs, but I'd have to go back an try a test to verify.  It also has the potential to affect any output to data collectors (such as via TrimbleLink).

As such, I can actually understand the desire for an "automatic warning" if a drawing is setup incorrectly.  And at least for any project here in Colorado, "International Feet" is ALWAYS wrong.

[mjfarrell]

As such, I can actually understand the desire for an "automatic warning" if a drawing is setup incorrectly.

Except that warning would probably not do the person(s) that didn't know any good to know what units the drawing is in. As you said yourself there are those that simply don't know the difference.
So imagine the impact of a dialog box popping up on their screen that reads:

Drawing is in US Survey Feet


They click OK to dismiss the box and still haven't a clue, despite now know 'knowing' what units the file is set up in.
This isn't the same as knowing what units the project's drawings should be in and knowing where and when to verify that said drawings for the project are actually in the right units.

It would appear that what the user really requires is a single TEMPLATE that is always set to the correct units.
And, or a routine that would set the drawing to the correct units based on some file in the project folder so that it would handle US Survey feet or Meters or whatever unit that particular project was supposed to executed in.

[sinc]

It would appear that what the user really requires is a single TEMPLATE that is always set to the correct units.
And, or a routine that would set the drawing to the correct units based on some file in the project folder so that it would handle US Survey feet or Meters or whatever unit that particular project was supposed to executed in.

This veers dangerously close to triggering my "Project Rant" again...   

[mjfarrell]

It would appear that what the user really requires is a single TEMPLATE that is always set to the correct units.
And, or a routine that would set the drawing to the correct units based on some file in the project folder so that it would handle US Survey feet or Meters or whatever unit that particular project was supposed to executed in.

This veers dangerously close to triggering my "Project Rant" again...   

You and me both.

[caddcop]

We are in the beginning phases of migrating from LD to Civil3D. We do both surveying and civil design, so getting our many descriptor keys ready has been a daunting task. So, I finally got a complete version and wanted to test regular points and survey points. I have a survey flle that plots a pair of points and eventually should plot lines between the linear items.
But I noticed a difference in the coordinates between my survey points and regular points. Turns out , my civil 3d template was still set to international feet, but the default setting for a new survey network is us survey feet.
When you review the coordinates in the panorama, they both list the coordinates from the survey file. But the survey points, when reviewed in graphics, are not at the listed coordinates.
Once I changed my file units to us feet, the points aligned. Bottom line, you better be aware of the units in use of all files used in all projects!

[mjfarrell]

We are in the beginning phases of migrating from LD to Civil3D. We do both surveying and civil design, so getting our many descriptor keys ready has been a daunting task. So, I finally got a complete version and wanted to test regular points and survey points. I have a survey flle that plots a pair of points and eventually should plot lines between the linear items.
But I noticed a difference in the coordinates between my survey points and regular points. Turns out , my civil 3d template was still set to international feet, but the default setting for a new survey network is us survey feet.
When you review the coordinates in the panorama, they both list the coordinates from the survey file. But the survey points, when reviewed in graphics, are not at the listed coordinates.
Once I changed my file units to us feet, the points aligned. Bottom line, you better be aware of the units in use of all files used in all projects!

Yes, except the survey setting is not the Drawing Settings, setting that the originator of this discussion was attempting to be alerted about.
So they would really need a tool that would list BOTH the drawing settings (Units) AND the Survey database settings. Or as you point out their efforts would still yield bad results.