Insert Spatial Reference System ID (SRID) in a DWG ?

[jlc.pub]

Hi,

We are trying to import a site map inside a security software.

To place the plan on a earthmap, this software require to have an SRID in the DWG.

I've tried to insert a location by using "Insert" tab > Location > Set Location from map.

It seems OK as I get a map behind my drawing but the security software does not interpret it as a "SRID"...

Could you help ? 

Thanks by advance,

[ChicagoLooper]

Is your ‘security software’ using Oracle or PostgreSQL? Neither one? You don’t know?

is your site map a shapefile? Your shapefile has a minimum of four components: (1) shp, (2) shx, (3) dbf and (4) prj. It’s critical to know the  FORMAT of your site map. 

<<If you only have a fraction of the  4 components shown above then the sender has no idea what to send you, and on your end, you’re unsure what you ought to and should've received.>> 

You need to open the prj or projection file (use Notepad) to determine the correct SRID. Projection files can get tricky. You should upload it or post a screenshot of it. 

BTW, your post belongs in the Map 3D forum, not here in the plain vanilla AutoCAD forum. A geospatial question like yours in the M3D forum will receive a more accurate response. 

Without looking at your prj file and trying to pull a needle out of a haystack, one can only guess.

 Is your site map in Lat/Long using a geographic coordinate system? If it is then you can try using SRID 4326. If it’s in meters using a projected coord sys then try SRID 3857. 

[jlc.pub]

Thanks for your answer. 

I'll ask regarding the SQL topic.

Concerning my site map, I don't understand your question, it's a DWG 2D plan (AutoCAD).

Thanks for the advice for Map 3D forum, I was not aware of a specific part of AutoCAD for map...

I will post in this forum too.

[ChicagoLooper]

@jlc.pub wrote

<<....it's a DWG 2D plan (AutoCAD)....>>

If it's a 2D drawing from QutoCAD with dwg extension, then it needs to be georeferenced. You'll need to assign a projection to the 2D plan. The projection will reference the drawing against the equator and North Pole. If you imagine modelspace is a model the earth, your map, the lines and points, need to know 'where' in modelspace to plop down. If you just plop them down in any ol' spot, they could end up in the ocean in the other program you're using.

Don't make the mistake of using geolocation tool with Bing Map to accurately establish your projection. That tool can, and does work, to create a projection but you need advanced know-how to make it happen, so dabblers beware, you can't simply click icons in the ribbon to georeference a map because some judgement (know-how) is involved.

You can either use Map3D or Civil3D to correctly georef your map. Depending on your version of Cad, you can also download the Map3D Toolset for use in vanilla Cad but doing so comes with a warning--you must know how to use them accurately, if used incorrectly, your map won't be drawn right and the blame will likely go to the downloded tools and not to the user and that's not fair to the Map3D and the toolset. 

[jlc.pub]

OK Thanks @ChicagoLooper,

At the beginning, I've tried to georeference it in Autocad with the georeference tool in the "insert" tab but if I understand well your explanation I need to use MAP 3D so I've installed it.

I'll play with it, thanks