The process of converting the coordinates of a map or an image from one system to another, typically by shifting, rotating, scaling, skewing, or projecting them.

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14
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3answers
2k views

Rubber sheeting in GRASS or QGIS

We are in the process of getting our property boundaries corrected and a side effect of this is that we need to move any assets that have been drawn relative to the property boundaries, so they are ...
11
votes
3answers
5k views

How to move vectors to specified coordinates in QGIS?

I have a layer of vectors located around, say, (100, 100), and I want to move them to new coordinate like (1000, 1000). How should I do it? Preferably using QGIS.
11
votes
6answers
578 views

Where can I find GIS data to test GIS coordinate operations?

I am trying to find some data that can be used to test GIS coordinate operations from one CRS to another CRS. So far all I have found is the Gold Data set and also various example points in the EPSG ...
11
votes
2answers
380 views

Huge differences between results for 7-param datum transform

I'm trying to transform a WGS84 lat/lon point 11d42'32.10629" E 5d12'56.75371" S in three different software packages (Proj4, GeoTrans and Leica GeoOffice) but I receive very big differences ...
10
votes
4answers
1k views

How to reproject spatial data using free libraries?

How can I use free libraries to transform spatial data? For example, I want to change the projection of a Shapefile within the code of my C# web application. How do I do that?
9
votes
2answers
7k views

Converting projected geoTiff to WGS84 with GDAL and Python

Apologies if the following question is somewhat stupid, but I am only VERY new to this whole GIS thing. I am trying to convert some projected geoTiff images to WGS84 using gdal in python. I have ...
9
votes
1answer
746 views

How can I see the coordinate transformation parameters in QGIS?

How can I see (and edit if possible) the transformation method and parameters used by QGIS for "on-the-fly" transformation, and then for saving data in another CRS? Like in ArcGIS? Here is the ...
9
votes
2answers
296 views

How do I perform a 3 parameter geotransformation and projection in Sql Server 2012?

I have a table with latitude longitude (NAD27) columns in it. I compute two other columns, X and Y, representing Web Mercator (WGS84) location. Currently I'm using a Arcmap to do this, by applying ...
8
votes
3answers
8k views

Coordinate System Transformation in ArcMap

For the Data Frame Properties on a map in ArcMap, what is the difference between selecting a new coordinate system and using a Transformation?
8
votes
1answer
2k views

How to reproject a raster file in QGIS with datum transformation?

I want to reproject a tiff raster file from projection A (ETRS89/UTM Zone 32) to projection B (DHDN/Gauss-Kruger zone 2). The two projections have a different datum so I have to use a datum ...
8
votes
1answer
3k views

Characteristics of different methods to convert ECEF to LLA

I'm trying to convert ECEF (Earth Centered, Earth Fixed) coordinates, which are defined in X,Y,Z, centered at (0,0,0) to LLA (Latitude, Longitude, Altitude). There are a couple of methods I found on ...
8
votes
1answer
1k views

Computational most efficient way to convert Cartesian to Geodetic Coordinates

As far as I understand the literature there are several ways to convert a set of geoecentric cartesian coordinates to geodetic coordinates Bowring, 1976 Borkowski, 1989 Lin & Wang, 1995 Toms, ...
8
votes
1answer
594 views

WGS72 to NAD83- how to find correct transformation

I am trying to get this raster file to convert from WGS72 to NAD83, but ArcMap10 doesn't appear to have the correct transformation listed. Where can I find this transformation, and/or how do I import ...
7
votes
1answer
2k views

How do I get a country border data set into my geography column?

I have a PostGis database with a multipolygon geography (as opposed to geometry) column. I'd like to fill it with the country border data available from ...
6
votes
3answers
461 views

How does ArcGIS determine which transformation to use when projecting on the fly?

How does ArcGIS determine which transformation to use when projecting on the fly? Where this would come in would be going from NAD 83 to WGS 84. Multiple transformations could be considered so how is ...
6
votes
2answers
4k views

How should I use GDAL to perform a transformation?

Greetings, I am a student who wishes to use GDAL to transform a series of images from Lambert Conformal Conic (EPSG: 9802) to Google Earth's WGS 84 (EPSG: 4326) for a web mapping project. I know ...
6
votes
4answers
7k views

How to reproject base layers in OpenLayers?

The issue is: I have vector/topo/image tiled maps for some places in north america which were published as ArcGIS Server REST service. These maps (A) are based in EPSG26912 projection. Now I wanna ...
6
votes
1answer
7k views

How can I transform GCS_North_American_1983 to GCS_WGS_1984?

I posted a thread today describing a shift in some of the NRC data (not all). Apparently, this shift has to do with conversion between Geographic coordinates, latitude and longitude and Transverse ...
6
votes
3answers
778 views

Retrieve polygon smallest MBR

I have a postgis table containing polygons. I want to transform my polygons to 4 points polygons : retrieve the smallest MBR. Here comes an illustration of what I want : My original polygon is ...
6
votes
1answer
1k views

Python script to convert Lat Long to ITM (Irish Transverse Mercator)

I am currently working on a python script that converts Lat Long (WGS84) to ITM. The formulas used are based on a paper published by OSGB (Appendix B): ...
6
votes
1answer
314 views

locating latitude-longitude point in a piste-map with matrix transforms

I am trying to plot points of a particular latitude longitude on this image of a Swiss mountainous landscape. What I am doing is I have some 54 known location-points plotted on this image (not ...
5
votes
5answers
6k views

How to convert coordinates from Gauss-Krueger to Longitude/Latitude?

I'm a newbie in the GIS world so please advise me :) In my .NET/C# project I need to show some shapes/points on the Bing Map. The problem is I have the Gauss-Krueger coordinates and need to convert ...
5
votes
4answers
679 views

Given long, lat, x and y, how do I find the projection?

I am using an app called farsite that outputs shapefiles that show how forest fires will grow. I am getting output in coordinates as X and Y values rather than (lon,lat) and am looking for a ...
5
votes
1answer
790 views

Python - OGR: Transform coordinates from meter to decimal degrees

I have a point in a shapefile. The shapefile is in a WGS_1984_Web_Mercator Projected Coordinate System. I want to get the coordinates of that point in decimal degrees with GDAL/OGR in Python. I am ...
5
votes
1answer
2k views

Mercator projection: problem with latitude formula

I'm trying to get the position of a coordinate on this map (source Wikipedia): If I'm correct than the formula for the position of the latitude would be: R * ln(tan(pi/4 + latitude / 2)) But ...
5
votes
2answers
5k views

Rotating a vector layer in QGIS with qgsAffine (or other method)?

I would like to rotate a set of vector points in QGIS an arbitrary number of degrees around a central point (or arbitrary point). This is similar to a recent question about creating a regular grid; ...
5
votes
1answer
182 views

How much error in a transformation?

I've been working in GIS for about a year and have a functional grasp of Projections and Transformations from within ArcGIS (10.0). Geosoft Oasis is another program we use. In working with our data ...
5
votes
2answers
541 views

Translating all features in a shape file

I have a friend with a bit of a problem. He has 1000+ shape files mapping paddocks and being used for precision agriculture. He's recently discovered the base station positions used to create these ...
5
votes
2answers
577 views

Why are the coordinates transformed with proj.4 off compared to http://valdemar.kms.dk/trf/?

I am trying to transform from epsg:4326 (wgs84) to epsg:25832 (utm ETRS89) using Proj.4. I am comparing the results with results from http://valdemar.kms.dk/trf/ . it seems like the results ...
5
votes
1answer
147 views

Moving a shape around the earth while maintaining the proper projection

What is the transformation needed to be taken on every data point of a shape to rotate that shape around the globe. I'm trying to figure out the math behind this kind of transformation so I can ...
4
votes
3answers
466 views

generate spatial geom from lat lon points for map in PostGIS

I am interested in a PostGIS implementation of the R-based soulution from a previous question, How can I convert data in the form of lat, lon, value into a raster file using R? Currently, I am hoping ...
4
votes
2answers
156 views

Why Different 2D Coordinate Transformation Methods Exist

It is a homework question but I couldn't find a satisfactory answer by googling. There are 4 different transformation approaches I'm asked for: - Conformal, - Affine, - 2D Projective, - 2D Polynomial ...
4
votes
2answers
463 views

What's the best projection for rasterization of random latitude and longitude data in the northern Atlantic?

I have a dataset in the WGS84 geographic coordinate system that I would like to interpolate along a grid using Python. It appears gdal_grid is not available through the Python bindings, so I plan to ...
4
votes
1answer
364 views

Experiencing transformation anomalies when performing a Save As to convert coordinates between NAD83-Z14 and NAD27-Z13

Good morning all: I have recently discovered QGIS and have been hoping to find a solution for converting bacthes of xy coordinates between two projection systems for our mapping system. I have known ...
4
votes
2answers
734 views

Cartesian world sized projection WKT/EPSG code?

I am after the EPSG code or Well Known Text (WKT) of a projection that puts the centre of the earth a 0,0,0 and each point is a cartesian XYZ distance from that. My existing data is in WGS84 ...
4
votes
1answer
3k views

Transforming geometry coordinates from SRID 4326 to SRID 3011

In SQLServer geometry field, I want to change the coordinates of geometry from one spatial reference system to another spatial reference system (from SRID 4326 to SRID 3011) by using ST_Transform. But ...
4
votes
1answer
401 views

EPSG operations and operation methods

Querying through the EPSG database, I can see the tables epsg_coordoperation where transforms and conversions between different CRS are stored, and epsg_coordoperationmethod which stores the ...
4
votes
1answer
229 views

Access is Denied error on ProjectEx call

I need to be able to convert a lat/long coordinate into a point coordinate and am having trouble getting my code to work. I created a test app isloating the code that is giving me problems. I'm ...
4
votes
1answer
3k views

Converting Lambert Conformal Conic to WGS84 using Proj.4

I am attempting to transform data from Lambert Conformal Conic lat/long and I am having some issues with the results. The shapefile I am attemtping to transform can be found here: ...
4
votes
1answer
2k views

Convert Gauss-Kruger to UTM

How to covert Gauss-Kruger coordinates to UTM coordinates with GeoTools java library? As I have figured out the location (zone, country) is important. I need the calculation for Slovenia.
4
votes
1answer
171 views

GDALWARP and OGR2OGR / CS2CS not agreeing on transformation

I am trying to transform some data (both raster and vector) from WGS84 to a Croatian Coordinate system defined by: +proj=tmerc +lat_0=0 +lon_0=15 +k=0.9999 +x_0=5500000 +y_0=0 +ellps=bessel ...
3
votes
3answers
606 views

FME - Possible to return a value from workspace?

I'm calling my workspace from the command line (either via Python or .NET to a system/os call). I'm parsing DWGs and pushing attributes to SQL Server in the workspace. Either the data validates in the ...
3
votes
2answers
866 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 ...
3
votes
2answers
535 views

Error transforming EPSG:4326 to EPSG:90013

When I'm trying to run a map on geomajas an error has occurred: o.g.internal.service.GeoServiceImpl - Problem during transformation EPSG:4326->EPSG:900913 of MULTIPOLYGON The multipolygon ...
3
votes
2answers
1k views

How to reproject from Michigan Georef to WGS84 in QGIS?

I am trying to reproject a michigan state land shapefile which is the NAD83/ Michigan Oblique Mercator EPSG:3078 to the WPG84 EPSG:4326 projection. However when i try to do this my map gets squished ...
3
votes
1answer
665 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
298 views

Is a WMS map always a constant scale?

If I get a map back from a WMS server is the scale always constant over them map regardless of the reference system? So if I have a map which is 100 pixels wide, will the point at 50 pixels always ...
3
votes
2answers
74 views

Is transformation of spatial data lossy?

I have a shapefile that contains data of a country from the following Geographic Coordinate System ( GCS_North_American_1927 aka NAD27 ) contents from the shape file .prj: ...
3
votes
4answers
638 views

Issues using geographic and projected coordinate systems QGIS 2.0

I am having issues with QGIS 2.0.1 working between local projected coordinate systems (such as OSGB36, NAD83) and Geographic systems (such as WGS84). The stock answer I have been provided is 'load ...
3
votes
1answer
703 views

getting the specified geographic transformation, or at least the GCS, of a data frame

First, the TLDR digest: I'm getting a bogus value from dataFrame.geographicTransformations on some machines; how do I get the correct value as shown in the properties dialog? and/or Given a spatial ...