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.
13
votes
3answers
962 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 ...
10
votes
4answers
2k 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.
10
votes
6answers
461 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 ...
9
votes
4answers
627 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
244 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
4k 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
255 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 ...
8
votes
1answer
477 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
540 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, ...
7
votes
1answer
1k 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
2answers
4k 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 ...
6
votes
2answers
2k 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
1answer
4k 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
616 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
601 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
150 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
4answers
593 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
66 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
424 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 ...
5
votes
2answers
2k 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
870 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
369 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
444 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 ...
4
votes
5answers
5k 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 ...
4
votes
4answers
3k 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 ...
4
votes
1answer
1k 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 ...
4
votes
1answer
274 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
1k 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
199 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
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.
3
votes
3answers
450 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
647 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
368 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
691 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
530 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
282 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
1answer
161 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 ...
3
votes
2answers
249 views
How to transform coordinates to location in x-y grid in R?
I have a polygon with a 40m diameter and several points that lay inside it. Now I want to reformat the point locations (projected in DHDN/GK-3, but could vary) to x-y coordinates ranging from zero to ...
3
votes
1answer
176 views
How does latitude of origin work in Mercator
I'm trying to make a coordinate transformation using GDAL/osr python bindings. I have a longitude an a latitude and I want to transform them into the mercator coordinates.
So I define the mercator ...
3
votes
2answers
50 views
Performance loss for OpenLayers EPSG transformation? Storing GeoJSON coordinates in lat/lon or in native map projection?
For a project the map projection is EPSG:32468 (tiles). On top of the map, two or three GeoJSON LineStrings should be displayed using OpenLayers. Each LineString has about 1500 coordinates.
...
3
votes
1answer
321 views
Transform multiple layers as one unit in ArcGIS 10?
The general/conceptual question:
Is there a way to transform multiple layers together in ArcMap 10 (on Windows XP SP3) as one unit?
More specifically:
I have an ArcMap document with a georeferenced ...
3
votes
1answer
836 views
How to transform shp file into raster file in Quantum GIS?
I'd like to transform a shape file into raster file in Quantum GIS... and the opposite way back also (raster to shp). Can you help me?
3
votes
1answer
252 views
How do I perform one-step transformation in python?
I would like to perform transformation for this example data set.
I have here four pairs of adjustment points and want to transform given point coordinates from primary system to secondary system ...
3
votes
1answer
338 views
PostGIS 2.0 ST_Transform with Rasters cannot find custom SRID
I'm trying to calculate an average value in a buffer around a point.
Given a raster in EPSG 4326 and a similar point, this is fine, except that the values will be skewed as they are not projected in ...
3
votes
1answer
89 views
How can i get a transformation-parameters-report (spatial-adjustment)
everyone!
In ArcGIS resource center about spatial adjustment (How Transform works), there are transform report like this !
Scale (X,Y) = (249.927,249.927)
Rotation (degrees) = (0.362) Translation = ...
3
votes
1answer
111 views
Debugging FMW memory usage near Group-based Transformers
I have a large FME FMW file which is using a lot of memory at runtime. I have been tasked with trying to find ways to reduce the memory footprint.
Early on in the workbench there is (what I assume ...
2
votes
3answers
633 views
How can I transform some KML data to Sql Server 2008 using FME?
I've just downloaded FME 14 day trial. I'm trying to see how easy/hard it is to transform some KML data (a simple neighbourhood shape) into my Sql Server 2008 database using FME.
I sorta don't even ...
2
votes
2answers
165 views
How to perform multiple string transformations using one transformer in FME Workbench?
I am converting a .DWG file to .GDB. All fields in DWG file are of Char type. The target .GDB needs to have some attributes in Float data type. For now, I am using one StringFormatter transformer for ...
2
votes
3answers
115 views
What Danish position format is this?
I have been given a list of locations within Denmark. Most of the are in decimal degrees. However, some of the positions are in different formats and I can't figure them out. Does anyone recognize ...
2
votes
3answers
713 views
Transforming shp files to projected coordinate system
I have some KML files, polylines. I will convert them in grass to shp. How can I transform coordinates to some projected coordinate system? I was never doing it, so please help me. I need to transform ...
