Changing projection

[DennisWebb1984]

Hi, I am a civil engineer using AutoCAD as a project layout.  I'm not a draftsman.  I've used AutoCAD since the MS-Dos versions, before Release 9.  I've been around awhile.  I've been using Global Mapper to change coordinate systems and it is really easy.  I don't want to jump back and forth, plus some data Global Mapper won't take.  

I've got some survey data in State Plane.  I'd like to convert the drawing to Lat/Lon.  Is there an easy way to do this?  I've read a few threads about it, it seems complicated, but these threads are 15 years old.  Hopefully there's s simple way I've missed.  I'm not a GIS guy.  I understand .dwg and .dxf.  My only use of shape files is to convert from them or to them when sharing data with others.

Thanks in advance.

[ChicagoLooper]

Hi @DennisWebb1984 

What is your survey DATA that's in State Plane? xlsx? dwg? Some other format? Can you provide a sceenshot of the data? Or even better, upload the actual survey data?

Map3D will convert from State Plane to Lat/Longs. The procedure, however, depends on what you've described as your survey data. That survey might be THIS or THAT, and THIS may require this procedure and THAT may require another procedure. It might even require something else altogether. It all depends on the format of your survey data and what it contains.

[DennisWebb1984]

Thank you for your response.

Survey data was an example.  I use several types of data.  The USACE hydro-survey data is available in X,Y,Z files.  The X and Y are State Plane NAD83 Easting and Northing.  The depths are in feet.  I process it and use a point entity inserted the 3D location to represent the data.  Another example is current velocity.  I use a vector shaped block inserted at the State Plane X,Y and rotated and scaled appropriately for the water currents.  I would want the location changed from State Plane X,Y to Lat Lon while leaving the other data unchanged.  I cut down one of my files containing depth data and attached it.

Another issue is that I have georefferenced .jpgs of the navigation charts in AutoCAD as a backdrop to data.  It is very handy.  I use the align command.  It works great in State Plane.  When I try for a drawing in Lat Lon the two points align correctly, but the entire rest of the image is off.  I've tried several areas.  I've attached two screen captures which I hope show the problem.  You can see how the channel doesn't line up with the water in the chart.  Any help would be appreciated.

I'm simply afraid my lack of training in Lat/Lon is showing.  State Plane is so easy.  It's been a long time since I took surveying in college.

Once again, thanks.

[Pointdump]

Hi Dennis,
Thanks for posting your drawing.
To bring in geo-referenced photos or shapefiles into your drawing, you can use "Connect to Data" in the Map Task Pane.
Another way would be to transform the data using the >>>Attach/Query<<< method.
If you post one of your geo-referenced photos, we can provide specifics.
Dave

[DennisWebb1984]

The navigation charts are plain, dumb, .jpgs with no data attached.  I georefference myself with the align command using two known points.  Is there a way for me take a simple .jpg and embed the georefference data into it myself?  I realize that is probably not an AUtoCAD function and would require other software.

I'm out for most of the day.  I'll check out the >>>Attach/Query<<< method later.

Thanks so much for taking the time to help me.

[Pointdump]

Dennis,
The Map Command ADERSHEET will rubbersheet your jpeg's adequately.
Even better you can geo-reference an image using the Raster Tools(Command IRSHEET). Also QGIS, and most likely Global Mapper.
Dave

[ChicagoLooper]

Hi @DennisWebb1984 

One of the problems you MIGHT have is your data. It might not be georeferenced to begin with. Any attempts to add non-geospatial objects against a known coordinate system (CS) is meaningless because it won't land in the right spot. If your data is georeferenced then you must know its native CS and know it without guessing.  If you know its georeferenced but don't know the native CS used by the original author then it's STILL another problem compounding the issue.

You should upload some Lat/Long data (real data, not screenshots) so a step-by-step workflow can be provided. The concepts of adding Lat/Long data into New York State Plane can be applied to other geo-referenced data too. In the end, you'll learn to add data to your NY83-EF drawing regardless of the referenced used by the data provider. 

The screenshots and dwg file you uploaded is helpful but not ideal if you want to learn how. Real data, whether State Plane or Lat/Long, in its original format will be the most productive. If you have an image, then share the image itself rather than a screenshot of the image.

Your bathymetry data in the dwg, what was the original format prior to inserting it into Map3D? Can you share original file? Also, do you run Civil3D in addition to M3D? Civil will provide an alternate presentation of your data.

[DennisWebb1984]

Thank you very much.  You've given me something to play with for a few days.  I will report back.  I tried ADERSHEET, and couldn't get it very good.  Either I didn't use enough points (19) along the channel, or I went in the wrong order for a selection.  I'll try again tomorrow.

I did try IRSHEET and got an "unknown command" error.

I have a lot of questions, but I think it's best if I at least try to learn by doing.  

[ChicagoLooper]

@DennisWebb1984 

So.......using your uploaded drawing named NY Sample Depths and your image named NY Harbor 2.....I got this....

Blue lines:

This is an existing layer in your uploaded cad file NY Sample Depths.dwg. The layer, named CHANNELS, was turned the ON and the color was changed from white to blue. 

Jpeg:

This is NY Harbor 2.jpg. It was inserted using ALIGN command. The Rubbersheet command was NOT used.

Background Image:

This is Bing Aerial map.

Editorial:

Notice how NY Harbor 2.jpg conforms to Bing aerial background imagery (the jpg edges vs. Bing). The blue linework, Channels, is consistent with both the jpg and Bing map. The black lines that are part of the jpg are not accurate. The ALIGN command was used to place the image in the drawing.

So if keep the jpg and delete all other objects, I can name and save the drawing. Since the drawing has an assigned coordinate system  (NY83-EF EPSG 2260) I can use this saved drawing as an XREF. Whenever I use NY83-EF this Xref will insert correctly and it will be accurate despite not having a world file (jgw). 

[Pointdump]

Dennis,
"I did try IRSHEET and got an "unknown command" error."
Raster Design is a separate install. After installation you'll see a "Raster Tools" Tab.
Dave

[DennisWebb1984]

OK, THANK YOU FOR YOUR HELP.  There's a lot to absorb.  I think I am making a very fundamental error due to lack of understanding. 

I'm attaching two drawings to the is post.  "NY Harbor Lat-Lon.dwg" are the NY Harbor channels in latitude longitude.  I downloaded as a GEOJSON file.  Which I know NOTHING about.  I pulled it into Global Mapper.  I made sure the projection was Lat/Lon and saved as a .dwg.  When I opened it in AutoCAD it was not assigned projection.  I assigned it NAD83 Lat/Lon.  The other file is "Chart 2024 2000 NY East NAD 83.dwg" I used the Align command to georeference a chart in State Plane NY East NAD83.  I then set the drawing to that projection.

When I open "NY Harbor Lat-Lon.dwg" and XREF "Chart 2024 2000 NY East NAD 83.dwg" the chart is not in Lat/Lon.  It is way far away still in the same State Plane coordinates.

Both drawings, on their own, appear to be correct.  I have overlaid Lat-Lon data on the channels and it looks dead on.  I know the State Plane system and I've verified the "Chart 2024 2000 NY East NAD 83.dwg" and it correct.

I've been georeferencing charts in state plane for decades with no problems.

Thanks again and I'm sending the requested data in a another replay to avoid mixing up too much info.

[DennisWebb1984]

Attached is current data for NY Harbor.  This is actually a input file for a ship simulator so that mariners can practice in handling ships in these conditions.  Why the simulator uses .xml I don't know.  

I pull the current database into Excel and strip the header records.  I wrote a macro that puts the data in the proper format and outputs an AutoCAD script file.  Run the script and you get a nice vector plot.  This is something I recently developed.

What this whole thing was driven by is that I want to show the vector plot on top of the navigation chart as a backdrop.  The currents are model output, they may not be exactly right.  I can edit the vectors (rotate, scale, delete, whatever) and use the DATAEXTRACTION command to output the position, heading, and scale of the block "VECTOR".  I run it through an Excel macro and get a new current data file for the simulator.  It's way cool.  I just want to add the chart as a backdrop.

Yes, I could do some gyrations and convert the current file to state plane, edit it, output it, and convert back to Lat/Lon.  I don't want to do that.  First, it admits defeat that I couldn't make AutoCAD do what I wanted.  Second, every time you handle data your run the chance of some sort of error.  Third, simulator time is expensive and who wants to waste their clients money?

Thanks again.  I hope this clears things up.

[Pointdump]

Dennis,
Wow, thanks for attaching all that data. I'm looking through it now.
Can you attach the original GEOJSON file? You'll need to zip it first, then the forum will allow you to attach.
The ALIGN command will get you close, but cartographers usually geo-reference maps with a minimum 9 points. The "NY 2024 150 DPI.jpg" image has a nice 1 minute grid. If you don't have Raster Design, the free QGIS does just as good a job.

Dave

[O_Eckmann]

Hi @DennisWebb1984 ,

If you have JPG maps which are in state plane, it's better to keep working in DWG with state plane, and attaching/quering other DWG in various CS to change projection to State plane.

Here a possible solution to convert all data into CS of Chart 2024 2000 NY East NAD 83.dwg

[DennisWebb1984]

Thanks.  I'm still trying to absorb all this information.  Here is the original  GEOJSON file.  It is huge and covers all the US.

[Pointdump]

Hi Olivier,
Good run through on the Attach/Query workflow.
Dave

[Pointdump · Accepted solution]

Dennis,
Here's the steps to use IRSHEET. You can also do this in QGIS.

The NY 2024 150 DPI.jpg has nice 1 minute grids, so I created COGO points with these:

-74°18',40°47'
-74°00',40°47'
-73°48',40°47'

-74°18',40°36'
-74°00',40°36'
-73°48',40°36'

-74°18',40°26'
-74°00',40°26'
-73°48',40°26'

Dave

[DennisWebb1984]

I used ADERSHEET because that's what I have.  It got close, especially considering I usually use ALLIGN and two points.  I had a final MOVE in my project area and it is dead on.  I've attached a screen capture.  Thanks everyone so much for your help.  I now have something that works.  I still don't understand a lot.  Is there a good reference book or online course that you might recommend?  THANK YOU AGAIN!!!

[ChicagoLooper]

@DennisWebb1984 

Another feature you can add to your map are GRATICULES.

Lat/Long Graticules

1. Graticules are horizontal and vertical lines on a map that display a reference system's grid. The reference GRID you display doesn't necessarily have to be State Plane. It can display a Lat/Long Grid even though you've assigned State Plane to modelspace. I know, it's seems odd to assign SPCS to modelspace then display Lat/Long grid on layout tab but it's entirely possible. Your drawing still maintains SPCS despite Lat/Longs displaying on the grid. Clicking the REFERENCE SYTEM ICON found on the Layout Tools Tab starts the procedure.

Image-2

2. After clicking the icon, your cursor changes to a square. Next, select the viewport  where you want graticules. 

Image-3

3. The settings window appears where you establish parameters. Your settings may vary.

Image-4

And.....if you change your viewport SCALE by zooming-in or zooming-out using your mouse wheel, the graticules will automatically change too.

[Pointdump]

Dennis,
Good video >>>Here<<< by @jporter. 34 minutes well spent.
Dave