Downloaded a soil shape file from NRCS it is on UTM Zone 18 (NAD 83).
I want to overlay the tract line and Lidar topo which is in NJ SPC (NAD 83) in US Survey feet.
It appears the shp file is metric, rescaling I can handle, but my brain is not up for the UTM to SPC conversion.
I am working in Carlson Survey 2004 not ArcGIS, ArcView or ArcAnything else.
Paul in PA
Why not use Corpscon to convert a few strategic points?
Perhaps try a two part conversion via Coordinate File Utilities might get you what you need?
For example:
1. UTM to Lat/Long
2. Lat/Long to NJ SPC
That's what Global Mapper is so good for......
:good: :good:
Email me your shape file and I'll try to convert it and send it back to you.
CORPSCON Is What I Will Use
Last night I was wondering how I would convert the UTM file to SPC. It includes soil lines for an entire county and I had yet to sort through all the data for the Soil labels.
On the way out to the field this morning I switched mental gears. I will pick several points in my SPC file and convert them to UTM. I will put those points into the dwg with the shape file and trim to the perimeter of the point polygon. Then I will move the much smaller soil line area back into my SPC dwg, scale it and fit it in. Before going to the field I had stopped in the area NCRS office, where they handily printed out my area map and all my soil data. They also emailed me a tif file that I can overlay my project on to check. I will also use that tif as a soils key map on my Erosion and Sediment Control Plan.
This is for an engineering project. I have been very happy the last few years concentrating on surveying, but the engineer for this particular project backed out at the last minute.
Down the road I will covert the full county file to SPC but right now I have a short job specific deadline to meet.
Any comments on the amount of distortion to expect in a county wide conversion? Over the past several years I have been downloading ortho photos keyed to SPC in feet for various large surveying projects. On some my only involvement has been on GPS control. They are 10,000' x 10,000'. I will match that grid with 10,000' x 10,000' soil maps. My plans are to keep it as simple as possible and keep it all in dwgs. While it has not been a lot of projects to date more often than not they happen to require 2 or 4 ortho photos.
Paul in PA
The Advantage of Conformal Projections ...
Is that a simple 4-parameter (dX, dY, rotation, and scale change) will allow the transformation of one conformal projection to a plane to another conformal projection to a plane.
That's exactly how the Army Map Service accomplished the European Datum of 1950 - all of the old Grids & Datums were converted over to ED50 on the UTM Grid.
