DWG linework is not lining up!

i received a DWG with topo linework of buildings, utilities, roadwork, etc. and survey data of the same objects recently collected is just is not lining up; on the order of 2-8'. That is, to match the current survey, certain comparisons appear to need some sort of rotation, while others points i am comparing seem to have scaling issues, and of course there are areas where a simple shift in one bearing would set a good alignment.

i downloaded a hi-res aerial, and the DWG shows the same pattern of mis-alignment.

I have no background information on the DWG, other than it is in state plane grid coordinate system.

Is it possible i missed a step attaching the DWG or is there metadata somewhere that did not come with the file?

TIA,

OA

Sounds like you've set an improper CRS, sir.

Copy the following string:

(ade_projsetwscode)

and paste it in the Autocad command line: which answer (e.g. NIL, LL84,...) do you get?

NIL

i have been unable to locate this command or what you are referring to in my help books. Please elaborate!

thanks, oa

if I understand correct your talking about 2 sources of info one a ground survey the other a dwg from some where. Pretty simple the dwg was probably originally digitised from a aerial photo, I can asure you we use GIS every day and we have property boundary in the photo's more than 3' 1m into property next door. We use a few trick to fix them. We changing technology the maps are becoming more shall we say "Accurate". Hand held GPS cheapy +- 15m 45' stay a while gets better.

The gis maps and ground co-ordinates take into account all sorts of stretching and shrinking to create the final result, stuff like curvature of the earth. If you were to build two identical sky scrappers well apart they will both be true vertical but observed they would not have parallel outside walls.

BIG AL - after lengthy detective work, it appears what you describe is what happened. GIS work with large errors caused a DWG to circulate!

Thanks!