Survey Pro help to Translate and Rotate

Sure...In the main menu goto "Adjust"

You should see "Scale" "Translate" "Rotate" "Traverse Adjust"...personally, I like to rotate the coords first, but it doesn't really matter.

In the "rotate" screen, you should see a point selection box on top this is where you'll enter the point base point to rotate from

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under that, a "Rotation point" selection box;

a choice between "Simple Angle" and "Old and New Azimuths".

I like the old and new azimuths choice....now if you know the old bearing and the new bearing, then you can just enter them manually here..if you don then click on that..that should cause a pop-up box to come up and should be "Old Azimuth" and "New Azimuth"..next to each is a pull down box that has a list of ways to come-up with the old azimuth (note: you can also use bearings by toggling the arrow on the left side of the screen)

I like from "choose from list" :

Pick the points that are on the old system...say 2 & 3

it will revert back to the rotate screen, which will have the pre-rotate bearing.

now click on the "new Azimuth" pull down box.?ÿ Again If you know the state plane bearing between the two points you can just enter it manually.

Hit solve.

It will rotate the points for you.

To move the points:

Got "Translate"

It should still have the points that you previously choose to rotate

click "Translate by Coordinates"

you can either enter the old coordinate values manually or you can toggle to translate by "Point"

enter the old point then enter the new point on the right side of the screen.

Hit solve

You should now have everything rotated and translated, as always check your work

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I hope this helps...I would export the points out to?ÿ a text file before you start rotating and translating..

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I know nothing about the software, but the words "erroneous coord system" are worrisome. GIGO (Garbage In, Garbage Out) is always operative.

@mathteacher

I think "erroneous" was meant to imply "assumed" or "arbitrary".

The pre-calculated points are coming from a survey without any starting coordinate values given, but related by bearing and distance. An assumed starting coordinate is used for office calcs, and once two or more of those points are found in the field, the whole range of calc points can be aligned (translated and rotated) to the "working" (state plane, previous project, etc.) coordinate system.

@mathteacher

He meant to say " assumed coordinate system"  I do it all the time, save and except for today's survey which will be on a state plane system from the git go.  (^_^) 

If your pre-calculated points are done in a separate program, as on your PC, there should be no difficulty in doing the translation/rotation you wish to do.

Depending on the version of Survey Pro you have, if you enter the points in a manual traverse mode, with side shots from occupied points, the Survey Lords and Masters at Spectra Precision decided, for whatever reason, you should not be able to move points with dependent points measured therefrom, a la, sideshots from traverse points.?ÿ That makes sense in some universes but seems to tacitly presume that you could not manage that properly.?ÿ There are ways around it but they do require some juggling.

If, on the other hand, you have computed these coordinates in another .Survey file and imported them into a new job, should be no problem, or if you did so on your PC and loaded them onto the field computer, that should no create an issue.

@joe-the-surveyor

Thank you for the very detailed reply!  I will try this tomorrow!

Also, in response to "erroneous coords" ... yes, this was pre-a.m. coffee language, pardon using the wrong word 😆    'Assumed would' be what I was looking for.

@goodgps

i see. I don't have the software to do this, but perhaps you will take a couple of minutes to do it.

Consider these 4 NGS points in North Carolina: DG9490, FZ0075, FZ0292, and DG9540. 

The table below gives both the NC state plane coordinates and the UTM coordinates for the four points. The problem is to use any three points to rotate and translate the UTM coordinates to state plane coordnates, use the rotated/translated system to position the fourth point and compare the computed position to the actual coordinates.

I really don't know what the result will be, but NC state plane is Lambert and UTM is Transverse Mercator. I'd love to know if the rotation/translation produces accurate coordinates.

@mathteacher

I see what you mean. Translating/rotating between different projections with significantly different inherent distortions would indeed cause some problems.

Most of the time the field translate/rotate is used solely for monument searches within a small area. If you find two or three monuments and you know which calc points they correspond to, you can do the translate and rotate, then begin staking out to the other calc points. Really helps if occupation does not match property lines, or you can't get a good signal from the locator in the vicinity of a monument.

There are some firms that have their crews do the above and then slam new rods in at calc points for whatever property they are surveying. This can cause all sorts of problems down the road, especially if there are any discrepancies between record and found distances/angles.

But proper procedure is to bring back the field data for processing/QA/QC before boundary analysis is done and a solution is found. Then final calc points are created before the crew returns to set monuments.

@rover83

It's easy to forget that the coordinate systems are just sophisticated models of the real world. But losing sight of either their sophistication or their model status can create serious problems.

Posted by: @mathteacher

@rover83

It's easy to forget that the coordinate systems are just sophisticated models of the real world. But losing sight of either their sophistication or their model status can create serious problems.

Agree 100%

While the age-old 2-dimensional ƒ??scale & rotateƒ? technique still has a place in modern surveying, its [proper] application is limited at best. When we are talking about a SMALL area with little relief (a somewhat ambiguous distinction), then application of this method usually works just dandy. Unfortunately, I see this method applied to projects and scenarios where the results are unsatisfactory, if not down right disastrous.

Loyal

Posted by: @rover83

@mathteacher

I see what you mean. Translating/rotating between different projections with significantly different inherent distortions would indeed cause some problems.

The example of UTM to Lambert SPC will likely be worse than local coordinates to SPC, which start out flattened at a local point instead of some distant central line.?ÿ But any of these need to have scaling as well as rotate and translate.

@bill93

The exercise was indeed rigged to make the point. Doesn't at least some field software assume a Transverse Mercator projection for 5000, 5000 type systems or localizations? I don't think those projections are baseless, but they might be.

You've done quite a bit of work with such transformations, haven't you? I remember some very interesting work that you posted about that.

Posted by: @bill9

The example of UTM to Lambert SPC will likely be worse than local coordinates to SPC

I was surprised how well it matches for a project spanning 4 km.?ÿ I did it in a spreadsheet. You need the scale factor and convergence angle for the points in each projection, which are on the NGS data sheet.

a) Reduce the UTM by the millions, hundred thousands, and ten thousands to have smaller numbers to manipulate.?ÿ This may not be necessary with the precision available in the spreadsheet, but it made it easier to plot to see the shape of the figure.

b) Multiply by the approximate average of?ÿ (SPC scale)/(UTM scale) which I rounded to 1.000327

c) Rotate by the convergence angle difference between the projections, as averaged over the four points, -1 09' 45.67" or -1.1.16268611 deg.

?ÿ ?ÿ ?ÿ N(spc) =?ÿ N(utm) * sin + E(utm) * cos?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ E(spc) = N(utm) * cos - E(utm) * sin

d) add back whatever N and E constants it takes to translate the coordinates to near match

e) find the differences from the original SPC, here all between -0.002 to +0.003 meter N and -0.007 to +0.007 meter east.

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As an aside, I don't recall what prior posts with coordinate manipulations you refer to.?ÿ I have implemented lat/lon to Iowa Regional Coordinates (LDP) in a spreadsheet and perhaps that was what you refer to.

@bill93

Seems like you did something with linear regression and Lambert to TM points. It was pretty good math.