Reprojection Question

RE: Reprojection Question

kcaitch — Thu, 03 Apr 2014 12:14:16 GMT

Inga was able to look at the files and get things to work. There are several steps involved and I am not going to try and simplify this solution, so here is her explanation (without photos). Thanks again Inga.

Create a new design file.

Set the active GCS to LL84

And have it change the storage units to degrees.

Then go to the working units of the file and increase the resolution. By default it’s only set to 10,000. Change it to 1,000,000.

You now have a design model that is set up correctly. I strongly advise that you save this and use it as a seed file for future projects of this nature.

Onwards…

In your CSV file, I suggest that you remove or replace all the # in the column headers. # is a reserved character used by Excel.

Just use an _ or similar.

Also in your CSV file, edit/replace the longitudes so that they are negative values.

We are in the western hemisphere so the negative is expected.

Run the import, data is correctly placed.

Now…..

Create a new design file.

This will be used for the reprojection. Note that the working units of this file are feet or meters or survey feet.

If you create a new model in the file above, then it will inherit the working units of the active model which is set in degrees and 10000000 units per degree. This will cause the reprojection to fail.

Define the GCS

Attach the imported file as a reprojected reference.

Confirm the location via Running coordinates.

Also, confirm that the data is correct by using the Google Map tool.

The location is correct-

If all is well, merge the reference into the master model.

Done.

RE: Reprojection Question

Mathieu St-pierre — Wed, 02 Apr 2014 19:54:36 GMT

Ken,

I don`t think the unit format is the problem.

I think the .DGN before you set the GCS to the model should be enough to check what is going on.

And also the destination GCS info.

Thanks,

Mathieu

RE: Reprojection Question

kcaitch — Wed, 02 Apr 2014 17:34:17 GMT

Inga,

Which files would you need? the VRT, CSV, and DGN? Would I be able to e-mail them directly to you?

RE: Reprojection Question

kcaitch — Wed, 02 Apr 2014 17:32:07 GMT

Mathieu,

I checked the settings and my data range is within the min and max, however, my data is in decimal degrees whereas the GCS is in DMS. Would this be the issue?

RE: Reprojection Question

Mathieu St-pierre — Wed, 02 Apr 2014 17:04:24 GMT

Hi Ken,

One thing you might want to double check is if the destination GCS valid region is correct for your data. Indeed most GCS are only valid in a particular area, area which is available during the selection of the GCS (see the field pointed by the mouse cursor on the screenshot below).

Thanks,

Mathieu

RE: Reprojection Question

Dan Weston — Wed, 02 Apr 2014 17:02:37 GMT

If you just need to see the E, N values for a point, use the ACS & Position readout as-described in this article: Display X, Y, Z Coordinates. Changing the Geographic Coordinate System and performing a re-projection will move, scale, and rotate the elements from their original position.

I'd be interested to see what Inga finds out about the data in that file too.

You don't need to set the GCS to the equivalent coordinate system of the imported data. If you are preforming civil engineering tasks, the likelihood that you are working in Degrees is pretty slim. Choose an appropriate Projected Coordinate System, one with Linear Units, and then perform the import. You will be presented with the option of re-projecting the data, and it should come in correctly.

RE: Reprojection Question

Inga Morozoff — Wed, 02 Apr 2014 16:02:19 GMT

You write: all the elements now have an origin of 0,0

Can you share or post the file?