I am a fairly new user of the Map 3D. We have a map created for our city with all our utilites, zoning, etc. plotted out and we have some very old aerial imagery attached to it.
Just a few months ago, Pictometry flew some new hi-res imagery for me. I have individual ortho tiles and one large ortho-mosaic. When I try to install the imagery, it doesn't line up anywhere close to where it should be on the map. How can I go about getting my imagery and my map lined up?
Thanks for any help
Brian
Thanks for the suggestion. I can't quite seem to get it to work right, but I'll keep messing around with that command.
Thanks
In newer versions it's on the Stataus bar.
On older systems type in _MAPCSASSIGN.
bkesting wrote:
I'll keep messing around with that command
As first attempt, I'd try to line up the imagery to the vector, by means of the simple _ALIGN command.
Afterwards, I'd run the "fine tuning" of the powerful _ADERSHEET routine.
Be careful of the rubbersheeting or that command. Do a save of the dwg before you use it and saveas after each move or edit. I have seen too many users end up with trash and no way to get back to the original work.
What format did you receive the orthos in? The easiest (for alignment purposes) is TIFF images with TFW "world files".
My current base map doesn't appear to have any coordinate system applied to it. It must just be "floating in space".
My ortho imagery (tiles and mosaic) are in .ecw fomat. (Though I think I can convert them if need be).
You should be able to work it backwards. If you can determine the coordinate system, size, and "base" coordinate (there is a good explanation of TFW >>here<<) of the ecw file then you could assign that system to your vector data. The provider will have image coordinate reference information.
Align and rubber sheet should be last resorts IMHO - only used if there is no other option. It might be worth your time and effort to get your vector data referenced to the "real world" somehow (control points, survey monuments, etc). It depends on your ultimate goal. If this is a 1 off then rubber sheet it.
fieldguy wrote:
TFW ... of the ecw
Well, I would disagree with that, sir.
1] A worldfile does NOT contain any projection data, so you can't figure out to which EPSG a raster belong
2] An .ecw does NOT need a worldfile, because its header contains full projection/location info on the Earth
I think the best resource to work with is a Geotiff, because, once you kept its header, you can edit it in several free tools e.g. Gimp or Irfanview.
And finally, to transform a just-scanned raster into a rich Geotiff, my advice is only one: the opensource Qgis.
I can just do a "move" and most of what I need works fine.
I've tried assigning a coordinate system to my existing drawing, then bringing in my imagery and I must be doing something wrong, because I either get errors or it just doesn't line up.
1) I found a point on Google Maps of my base map to get a lat/long reading.
2) I ran MAPCSASSIGN and set a coordinate system (NE83F specifically) as my coordinate system
3) I converted the Lat/Long numbers into State Plane (NE83F) coordinates
4) I entered a point on my CAD dwg with those coordinates.
5) I moved my dwg using "Move" to using a reference point on the drawing to its "Lat/Long" point I created.
When I try to bring in my new imagery I get the warning "Source Coordinate System not found". What does that mean?
(I can bring in my imagery with no coordinate system defind on my dwg and just move the dwg on top of the imagery, but I am trying to get things geo located in the right spot if at all possible)
bkesting wrote:
What does that mean?
It means that your raster is neither georeferenced nor having a worldfile.
If you wanna line up to a vector map, you must align it according to 2 known coordinates points.
Import that raster thru the _IMAGE command, then run the _ALIGN command to calibrate it.
Finally create its worldfile by means of this tool.
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