Tagged Questions

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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0answers
20 views

Applying proper correction from True to Grid

I have a very basic question that will seem very elementary to most who observe this website. The reason I ask is because I have been told to difference answers and I'm now a little confused. So, here ...
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0answers
15 views

How to snap Vector Layer projection to Raster layer projection in QGIS?

I have raster in correct projection. I used ShapeFiles, and marked objects(manually), but i found out that my vector layers have different projection, so they have different size and position. Is ...
5
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1answer
64 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 ...
0
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2answers
44 views

Thiessen Polygons and Coordinate Projections

I am trying to perform a Thiessen Polygons analysis in ArcGIS 10. My DEM is in GGRS_1987 and the point set I downloaded from Google Earth is in WGS_1984. The points display correctly but when I run ...
0
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1answer
57 views

“Request contains a format not offered by the server.” Error when using CRS transformation with WMS in QGIS

When I try to load a WMS layer which has a WSG84 as a default projection and use a CRS transformation on it, it gives this error message: Request contains a format not offered by the server. The WMS ...
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0answers
30 views

Total station problem [duplicate]

I have total station data in local coordinates in excel format. Now i want to transform it into global coordinate (in utm) to correctly overlay on the actual place. What is the method?
2
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1answer
44 views

ArcGIS JS API Polygon's WKID conversion with gsvc.project

I'm trying to convert polygon from wkid 3301 to wkid 4326. I've been using this code snippet for converting points, but I'm not sure how I would accomplish this to create a polygon object. I'm not ...
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0answers
39 views

Geokettle transformation for FileGDB to SHP

I want to transform FileGDB layer to Shapefile on Geokettle. Firstly i added OGR Input and than i added a Shapefile Output. And i entered parameters shown on the screenshot but i got errors for ...
1
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1answer
53 views

PROJ4 C++ API: Amersfoort RD New to WGS84

I try to convert between dutch RD New (EPSG:28992) and WGS84 (EPSG:4326) via PROJ4 C++ API. On the console this works with: cs2cs +proj=sterea +lat_0=52.15616055555555 +lon_0=5.38763888888889 ...
3
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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. ...
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0answers
23 views

How to identify grid shift file used by osgeo in Python?

I wrote a Python script reprojecting points from a source coordinate reference system (SCRS) to a target one (TCRS) both identified by an EPSG code. I would like my python script to retrieve details ...
2
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1answer
45 views

Transformation of user-defined projected coordinatesystems

I want to transform from one projected coordinate system (pcs) to another using ArcGIS 10. Unfortunatelly the starting system is not predefind by ESRI and thus I´m not sure the software is doing what ...
9
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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 ...
2
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2answers
63 views

Where can I get the list of Geographic Tranformations in ArcGIS and the area where they are aplicable?

I have some data in Provisional South American Datum 1956, and I need to project it to Web Mercator with WGS84 as the datum. When I use the project tool in ArcGIS desktop, it requires a Geographic ...
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0answers
12 views

Units of Geometry & Geography data type [duplicate]

When you store data using the Geography data type (like in PostGIS), is it always in lon/lat in degree decimals? For the Geometry data type, what are the units used in the coordinate pairs? Can it ...
0
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0answers
48 views

OpenLayers - Transform resolution

I want display resolution of the map for each zoom level. So I've create event listener for zoom event, but it is displayed in different projection that I want (I guess). So I need to transform this ...
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2answers
56 views

Lambert projection with one or two standard parallels and proj4

I'm sure there is a gap in my understanding, but I haven't been able to identify where it is, nor how to fill it. My issue is this: I'm transforming lon lat coordinates into a lambert conformal ...
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0answers
27 views

Can QGIS transform a set of XY coordinates to a new set reconciled to UTM coordinates?

I have a large data set of coordinates (in meters) measured on the ground relative to a set of trails in Peru. These were generated in the 1990s with a tape measure, and there are about 3000 of them. ...
1
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1answer
70 views

Projection WGS 84 is slightly displaced referring to a hillshade in QGIS

I have a hillshade and a vector layer. The vector layer is slightly displaced referring the hillshade. About lat=100m and long=175m The CRS of the project is EPSG:3397 - PD/83 / Gauss-Kruger zone 4. ...
2
votes
2answers
117 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 ...
2
votes
1answer
60 views

Setting coordinate systems in QGIS: “transform error caught”

I'm learning how to use QGIS (v 1.8.0 "Lisboa") on Mac OS 10.6.8. My goal is to create a simple county map of Illinois using the base data shapefiles available from the Illinois Natural Resources ...
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 ...
1
vote
1answer
89 views

How to reproject this vector layer?

I have a dxf file and use this tool to convert it to shapefile. Then I apply some affine transformations and get a shapefile that does not fit the shapefiles downloaded from osm (EPSG:4326). I know ...
1
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1answer
132 views

ArcObjects 10.1 .NET Convert Point from WGS1984 to OSGB1936

Please can someone help me convert a point in WGS1984 to OSGB1936, I have followed all the documentation (or so i think...) and yet have not made any headway into this problem. This is my code : Type ...
2
votes
2answers
141 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 ...
1
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1answer
51 views

How does ogr2ogr determine which transformation to use and how big would the introduced error be?

I want to convert TIGER data GEOGCS["GCS_North_American_1983", DATUM["North_American_Datum_1983", SPHEROID["GRS_1980",6378137,298.257222101]], PRIMEM["Greenwich",0], ...
1
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0answers
58 views

Using the CropCoverage Render Transformation in a Geoserver SLD (WPS)

I've yet to find an example on the web (or in code) of anyone using the "Crop Coverage" Render Transformation from a Geoserver SLD. Does anyone have an example or at least be able to point me to the ...
2
votes
0answers
254 views

Projecting point in Leaflet from EPSG 900913 (same as 3857) to EPSG 2232 with proj4js returning unexpected results

I have a leaflet map from which I want to be able to query an api that accepts x y values in EPSG 2232 as inputs. Leaflet doesn't handle point transformations like Open Layers does so I am trying to ...
1
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0answers
75 views

ArcPy 10.1 PointGeometry.projectAs()

I'm trying to reproject an X,Y passed in from an Add-in. So far this works fine: pointGeometry = arcpy.PointGeometry(arcpy.Point(x,y),srIn,False, False) projectedPoint = ...
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 ...
0
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0answers
65 views

coordinate transform from one srid to another in nettopology suite, c#

In a program using c#, .Net, I read a geometry field from a spatialite database into a variable of type GeoAPI.Geometries.IGeometry, in SRID 4326 (WGS 84). I want to transform this, in code, to a ...
0
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0answers
138 views

How use thin plate spline transformer to wrap image in c#

I'm new at programing with GDAL C#. I need to geotransform raster image (using GCP's) and bring it to the Merkator projection. With FWTools I can do this by using gdalwarp -r cubic -tps after ...
2
votes
1answer
339 views

Openlayers Transform not transforming a point from EPSG 27700 to EPSG 4326

I am trying to add Google street view functionality to a Openlayers Map. I have started by using 3 divs to hold the Openlayers Map (which uses a local tilecached base map), a google api map and ...
2
votes
1answer
34 views

OSGB conversion error

So I am using ArcGIS 10 and trying to work in British National Grid. My shape file is in WGS84 UTM30N. By chance I passed the shape file across to a colleague and we both transformed into BNG. When ...
0
votes
0answers
52 views

What's the difference between CRS 4326 , CRS 4978 and CRS 4979?

They are all based on WGS84. 4326 is called "geographic 2D", 4978 is called "geocentric", 4979 is called "geographic 3D". What are the differences between these three? Why are we using "geographic ...
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 ...
0
votes
1answer
111 views

Terrasolid - How to define spherical mercator (EPSG: 3857)

Im trying to define the srs EPSG 3857 inside Terrasolid sofware. I ran into a problem because the definition of the reference ellipsoid is given with a major axis and inverse flatening, not via both ...
1
vote
1answer
61 views

Problem transforming projection on outlying features from shapefile

I am fairly new to GIS data and as such please feel free to ask for extra data I might not have provided. I have some regional data from Natural Earth, more specifically this: ...
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 ...
2
votes
2answers
180 views

How to create a “Datum-less” projection in QGIS?

I want to use QGIS to do some georeferencing and image registration. On ArcMap10 I can define an "Unknown Projection", basically a default metric grid, and use it as a grid for georeferncing. In QGIS ...
2
votes
0answers
83 views

projection discrepancy with gdal (1.9) and proj4

I boiled the problem down to that python example: import sys try: from osgeo import gdal from osgeo import osr except: import gdal import osr if __name__ == '__main__': version_num = ...
2
votes
2answers
107 views

Coordinate system of a raster file to be introduced for transformation

I am working on raster data using GDAL. When I extract coordinate system information of the files I got this: PROJCS["Geostationary_Satellite", GEOGCS["GCS_Unknown datum based upon the custom ...
2
votes
1answer
198 views

Coordinate system of a MODIS file to be introduced in GDAL for transformation

I am working on MODIS data using GDAL. When I extract coordinate system information of the files I got this: Coordinate System is: PROJCS["unnamed", GEOGCS["Unknown datum based upon the custom ...
5
votes
1answer
420 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 ...
1
vote
2answers
319 views

Howto change OpenLayers BBOX request projection?

My map uses EPSG:900913 projection on the map. All coördinates in the database are stored in the 'normal' google format / GPS coordinates (WGS84). For instance, if you save a new location..Before I ...
2
votes
1answer
573 views

How to setup leaflet map to display a WMS layer in ESRI:102012 projection?

I have a WMS server that serves layers in ESRI:102012 projection. http://spatialreference.org/ref/esri/102012/ It accepts GetMap requests with srs=EPSG:102012 parameter. My goal is to display a map ...
0
votes
2answers
89 views

How to apply v.transform on a set of vector layers (GRASS 6.4)?

I have 64 vector layers, all of them must be warped using the v.transform module; the pointsfile is the same for all vectors. How can I apply the transformation recursively to all layers? I'm not ...
1
vote
2answers
253 views

Datum transformations, do we use wgs84 as an intermediate common reference?

I was transforming some data the other day using the 7 param helmert transformation and it got me thinking. I have a set of transformation parameters, but these only describe the transformation from ...
2
votes
2answers
264 views

Looking for formula for the Robinson projection

I'm looking for a source that describes how the Robinson projection is calculated. I'm going to use this for converting long/lat into Robinson coordinates in both R and in javascript.
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): ...

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