Per Loyal.
"GPS has made SPC obsolete big time, and it can be argued that "they" (SPCs) were functionally obsolete when EDMIs and micro-chips became available to the average Surveyor several decades ago."
"SURE...SPCs still have their place (as do UTMs), but IF YOU HAVE to "modify" them, then you probably shouldn't be "using" them in the first place!"
I totally disagree.
GPS has enabled SPC to do it's intended purpose, to reference all projects to a statewide cadastre.
That too many surveyors have failed to be able to in fact properly reference their alleged SPC projects is not a failure of the SPC system in general, but a failure of the surveys/surveyors individually.
With OPUS and OPUS-RS every surveyor that can turn on a box can get uniformly consistent SPC reference points. It is what is done with the correct data subsequent that becomes the problem.
Paul in PA
I agree with Loyal. However I believe there are many surveys where 200 or less ppm linear error isn't going to hurt a thing making I unmodified SPC a logical solution. Surveyors in general are kind of anal about wringing out those ppm on those two bit rebar.
> Per Loyal.
>
> "GPS has made SPC obsolete big time, and it can be argued that "they" (SPCs) were functionally obsolete when EDMIs and micro-chips became available to the average Surveyor several decades ago."
Although Loyal's logical fallacy continues to be that a novice user who doesn't savvy projections is suddenly going to be able to use some CUSTOM PROJECTION any more skillfully than the standard projections of the SPCS. That bit never made any sense.
If you can use custom projections, you should be able to use the SPCS since both have the same issues and both require reduction of ground distances to the ellipsoid.
> > Per Loyal.
> >
> > "GPS has made SPC obsolete big time, and it can be argued that "they" (SPCs) were functionally obsolete when EDMIs and micro-chips became available to the average Surveyor several decades ago."
>
> Although Loyal's logical fallacy continues to be that a novice user who doesn't savvy projections is suddenly going to be able to use some CUSTOM PROJECTION any more skillfully than the standard projections of the SPCS. That bit never made any sense.
>
> If you can use custom projections, you should be able to use the SPCS since both have the same issues and both require reduction of ground distances to the ellipsoid.
I think that is exactly the same thing Loyal was saying.
> > If you can use custom projections, you should be able to use the SPCS since both have the same issues and both require reduction of ground distances to the ellipsoid.
>
> I think that is exactly the same thing Loyal was saying.
I may have to find the thread where Loyal's remarks appear, but if he has concluded that the custom projections have no advantage over the SPCS for a user who has the understanding necessary to use both, then that is a new development in his thinking.
Loyal is right. The constant requests for reconciliation of Grid distance and ground distance confirms this. The discussion is generally even couched as "Grid vs. Ground". State Plane struggles to meet the needs of modern surveying. Several States have developed county wide projections. This would seem to be the best option for most areas of the nation. Published, combined factors near unity, North is near North.
Negative Shawn, Surveyors Still Struggle To Understand SPC
SPC is entirely adequate. PA maintains a statewide cadastre of georeferenced data, ortho photos, LIDAR topo, and 10 other GIS subjects on an SPC N & S system.
What we now have are button pushers who cannot calculate their way out of a paper bag without a software upgrade.
Paul in PA
Negative Shawn, Surveyors Still Struggle To Understand SPC
No argument there from me Paul. Except that the software generally doesn't help. It just masks the ignorance.
Negative Shawn, Surveyors Still Struggle To Understand SPC
Regarding products like aerial photography digital quads, etc., software is available to reproject those things into whatever projections you want.
Negative Shawn, Surveyors Still Struggle To Understand SPC
> What we now have are button pushers who cannot calculate their way out of a paper bag without a software upgrade.
Do you have any backup for that claim, or are you just feeling jaded today?
Negative Shawn, Surveyors Still Struggle To Understand SPC
>
> Do you have any backup for that claim, or are you just feeling jaded today?
Yes, but propriety prevents me from detailing my personal observations on the Internet. By all means ask your colleagues about the mechanics of projections at the next chapter meeting and tell me what you think. I was firmly opposed to the degree requirement until recently. But I've had a front row seat to the ignorance in our profession. Linebender's assertion that 200ppm is fine for many is true. This is mostly out of apathy or laziness I think. 200ppm is a lot.
Negative Shawn, Surveyors Still Struggle To Understand SPC
> >
> > Do you have any backup for that claim, or are you just feeling jaded today?
> Yes, but propriety prevents me from detailing my personal observations on the Internet. By all means ask your colleagues about the mechanics of projections at the next chapter meeting and tell me what you think. I was firmly opposed to the degree requirement until recently. But I've had a front row seat to the ignorance in our profession. Linebender's assertion that 200ppm is fine for many is true. This is mostly out of apathy or laziness I think. 200ppm is a lot.
I don't go to these meetings, I am not on the guests list. But you know, for decades, 1 : 5,000 has been the minimum requirement. It probably still is in many places.
Negative Shawn, Surveyors Still Struggle To Understand SPC
If the combined factor is 200ppm you'll squander your entire 1:5000 error budget on lazily ignoring the mechanics of projections. This leaves no room for observation error.
Negative Shawn, Surveyors Still Struggle To Understand SPC
In order to have a 200ppm error from scale your combined scale factor would have to be 0.9998. Unless you're surveying the top of Mt. Everest that's a pretty unlikely scenario.
Negative Shawn, Surveyors Still Struggle To Understand SPC
It would seem so, Lee, to flatlanders like you and me (I'm in East Texas). However I've seen a CSF of 0.9995 at ~10,000ft elevation in Southern Colorado in the Colorado South Zone.
Negative Shawn, Surveyors Still Struggle To Understand SPC
You will also get them at .9993 and at low elevations in central Montana. A function of one lambert zone for the entire state.
Negative Shawn, Surveyors Still Struggle To Understand SPC
Wow... one more reason to love South Louisiana lol
Negative Shawn, Surveyors Still Struggle To Understand SPC
Or Southwest Connecticut 🙂
> > > If you can use custom projections, you should be able to use the SPCS since both have the same issues and both require reduction of ground distances to the ellipsoid.
> >
> > I think that is exactly the same thing Loyal was saying.
>
> I may have to find the thread where Loyal's remarks appear, but if he has concluded that the custom projections have no advantage over the SPCS for a user who has the understanding necessary to use both, then that is a new development in his thinking.
Sorry, I should have said that is what Paul was saying, Loyal said the opposite. The title in the OP confused me.