Incorrect map data with some coordinate systems

[Anonymous]

Hello,

  I am working with Maps 3D 2015.  I have an issue with some coordinate systems loading map data for the wrong areas.

Most of the time things work out but there are several states that I cannot seem to get any maps for.  Most recently Maine has been causing me problems.

All 3 of the zones for the state of Maine seem to load map data elsewhere.

The western zone only shows mapping for New York,  The central zone shows Newfoundland, and the eastern zone shows New Brunswick.

I suspect that I am making a mistake somewhere here but am baffled because most of the time the maps display for the area I need to work with when I select the coordate system for the area I am working with.

I select coordinate systems based on the list compiled by Rick King.  This list occasionally loses its host so I have downloaded it.  I am aware that it is a bit out of date so sometimes need to move over a zone but it always gets me very close.  This list breaks down the entire US into coordinate systems used by county, a great tool and I would link it here if the most recent location that I had found it at was still active.

[parkr4st]

what zones have you worked with?

for example ME83-EF   (state plane east feet)

Map3D provides 25 choices for Maine.  what system(s) are you trying to use?

[Anonymous]

I try to work with the NAD83 systems and prefer to work in US survey ft as those match the units of everything else I need to work with.

[parkr4st]

without the code or EPSG code it is difficult to determine which CS you are using.

What projection is being used with the data files?  i.e. *.prj in the shp file set?

It seems as though you have a mismatch or non existent projection

[Anonymous]

The EPSG code for the CS I am using is 26848.  The issue also happens with 26847.  There does not appear to be a US feet CS for central maine so I also tested ME2K-C (meters) with an EPSG code of 3463.

I notice the issue when I try to pull in a .KML file from google earth.  The shape drops into the map and looks right but is over blank space.  I then zoom out and pan around and find that the background map that Autocad links (Bing maps) is not showing anything in Maine at all.  All of the imagery is of New york, Newfoundland, or New Brunswick.

When I link shape files or Import images/shapes from google earth they land in the blank space.  The shapes and images are NOT stretched or skewed as one would expect if assigned the wrong coordinate system.

I should also note that sometimes everything works fine.  For instance if I take an older drawing in the same general area and delete the contents and pullin my new objects everything is normal.  But if I try to start from scratch with a blank drawing and default or no coordinate system selected this happens.

[Pointdump]

JGD,

"...some coordinate systems loading map data for the wrong areas."

Specifically, what data and what coordinate systems? Please post both data and the drawing.

Even though the Map Library shows a "Maine Central" there are only two "official" zones, East and West:

Dave

[Anonymous]

Thanks for the help with this guys.  It turns out that I was operating in the correct coordinate systems but that autocad was not changing from one other another correctly.

  The intermittant function really had me stumped until last week.  I was running some other cad programs and overwhelmed my computer.  When I got it all back up again I discovered that all of the files that had maps out of place were working fine again.

  Through some experimenting, I discovered that I could start a new drawing, change the coordinate system, observe that the background map was not correct, save the drawing, reboot autocad, and re-open the drawing with the maps sorted out.

  Each time I created a new drawing and changed to a different coordinate system from whatever was in the previous drawing WITHOUT closing autocad, the maps were out of place.

 Once I am opening a saved drawing I can open as many as I want (within reason) in as many different coordinate systems as I want and it all works fine.

  I hope that this helps anyone else who has encountered this.

John D

[jim.poole]

I have found that Civil 3D can take up to 30 minutes to load the correct mapping data.

I was tearing my hair out for 10 minutes, then got distracted for about 20 mins, returned and it had loaded.

I can't find a way to force regenerate / reload the mapping... anyone else?

[Pointdump]

Jim,

Not quite following on "...load the correct mapping data."

Can you elaborate? What sort of data are you using? What version/service pack of Map 3D?

Dave

[jim.poole]

@Pointdump wrote:

Jim,

Not quite following on "...load the correct mapping data."

Can you elaborate? What sort of data are you using? What version/service pack of Map 3D?

Dave

Sorry Dave, I agree statement was a bit vague (written in frustration as I recall).

I was refering to the aerial imagery presented for certain projections (in my case, specifically some of the Pulkovo 1942 imagery).

I had noticed that the imagery was not correctly placed / aligned to a known topo we had.

No matter how many REGENs I did or on/off, save-reopen etc it was not in the correct place.

I'd taken to using a different projection (UTM) and transforming 12,000,000 west, then adding a bit of local tweaking / rotation, which was acceptable. Then one day I opened a Pulkovo projection drawing, got distracted for about 30mins, and whicn I came back the imagery had 'corrected' itself...

I am now much more patient, but waiting for >20mins, doesn't seem like a good method for checking....

[Anonymous]

Did either of you try setting your coordinate system and then saving, closing, and re-opening your drawing? I have since found that it is not necessary to actually close AutoCAD, just the drawing that is giving trouble.  I will admit that I never gave mine the 30 minutes it might have taken to sort itself out.  I wonder if opening a new drawing file forces the same map refresh that it is doing on its own 20-30 minutes after changing coordinate systems.

JD

[jim.poole]

Yes, tried everything (even full computer restart).

It appears one needs to sit and just wait - ohmmmm....

[ChicagoLooper]

Pulkovo.....What country, or better yet, what's the lat/long. (Intuition tells me Pulkovo42 is obsolete.)

Coordinate systems can be outdated in some countries. At times, they are politically driven, meaning a governing administration may suppress technological advancement or curtail funding for programs. Once the political party is replaced, things can change. The resulting change can be either an update or a total overhaul. If overhauled, the name or description of the CS may no longer be recognizable by outsiders or non-citizens.

Here's the proverbial Rub: When Autodesk updates CS Library with the new or updated CS you can have issues if you continue to use the old CS.

And contrary to popular belief, the coordinate system you assign to modelspace does NOT have to be the same as the coordinate system within the shapefile or raster. As long as the program recognizes both CS's, it will make the necessary transformation and plop it down in modelspace correctly; E.g. shapefile with a prj in UTM-meters and modelspace with SPCS-US feet. Cad will orchestrate harmony and your drawing will look good. A raster with geographic lat/longs and modelspace in State Plane w/US-feet, again, there will be harmony and your drawing will look good.