The process of translating a map or spatial data from one geographic projection to another

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6
votes
2answers
7k views

Basic proj4 conversion UTM grid -> longlat and back

I'm a GIS novice, and am struggling to understand how to drive proj4 to accomplish what seems like a simple thing. I've googled for a couple of days, but everything I find seems to presuppose quite ...
4
votes
3answers
7k views

Using the Proj4js library to convert from Google Maps to projected values

I'm using the proj4s javascript library (based on advice from this question I asked previously) to convert lat/long values on my webpage. This page receives the lat/long values from google maps and ...
9
votes
2answers
4k views

Derive WGS84 Longitude & Latitude from British Northings & Eastings

I'm looking for a fairly simple way to append columns with WGS84 longitude and latitude to a table containing northings and eastings. The source data is Ordnance Survey's CodePoint Open, which I is ...
4
votes
1answer
976 views

How to do stereographic projection conversion (w.r.t. changing point of projection)?

Given a stereographic point P1 projected from point P, and given another point Q, I would like to know how to transform P1's coordinates to that of a stereographic point Q1 projected from point Q. ...
3
votes
1answer
729 views

Ordnance Survey data to WGS-84

Recently I have reprojected Ordnance Survey data from British National Grid (ORD SURV GB) to WGS-84 using ArcGIS 9.2. After re-projecting I have found some shift in the data. Can any body guide me ...
3
votes
1answer
529 views

With CTM how can I get the latitude and longitude bounding box of a geoPDF?

Embedded in a geoPDF is info on the CTM - Coordinate Transformation Matrix. I am unfamiliar with this CTM. I know how to use python-numpy. How (or is it even possible) for me to use the CTM ...
4
votes
3answers
2k views

reprojecting geotiffs to spherical mercator using gdalwarp

I would like to reproject raster images (tiffs+proj+tfw) files too "google's" projection using gdalwarp. From what I understand, google uses epsg:900913/epsg:3785. What I don't know is how to ...
14
votes
5answers
2k views

Does Re-Projecting ShapeFile only update content of *.prj file?

if i wish to change the projection of some shapefiles from .. lets say NAD83 (4269) to WGS84 (4326) ... and by using some 3rd party app .... does this mean the .prj file is only updated .. and not the ...
3
votes
2answers
971 views

Which ESRI defined geographic transformation do I need to use to convert my “ NAD83 Northern Virginia” data into WGS 1984 Web Mercator?

My title pretty much tells it all.. I have a number of datasets in which I want to batch project from NAD83 Northern Virginia Datum into the correct Web Mercator projection.. When I do a straight ...
2
votes
1answer
2k views

How can I convert from EUREF-FIN coords to Lat/Long?

See question title, how can I Translate EUREF-FIN coords to Lat Long?
1
vote
2answers
719 views

Projected layer misaligned with Mapserver

I have a couple or raster files in epsg:23031 reference that i want to reproject to other reference systems (epsg:4326 and google projection) using the 'on the fly reprojection' of Mapserver. No ...
1
vote
1answer
1k views

How to convert from ITM ref to GPS ref ?

How can I convert from ITM ref (Israel new map) to GPS ref and from GPS ref to ITM ref? I need any C# sample code or formula for this. For example: 32.086156,34.769239 = 178364,665948 Or : ...