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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2
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3answers
35 views

matching coordinate systems by transforming and projecting

matching coordinate systems of all my data (transforming, projecting) My data uses the GCS_Bessel_1841 coordinate system. Would there be any inaccuracies if i would transform it to DHDN 3-Degree ...
5
votes
1answer
151 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 ...
0
votes
1answer
244 views

How to transform/convert Coordinate Reference System with Proj4 and php

Basically my question is: Can I combine the functions of proj4 with php in my server? For example, I would like to know if it is possible get data in WGS84 and transform in ETRS89. I need to get ...
1
vote
1answer
33 views

Automatically georectify raw Landsat scenes

I am working with 20 raw Landsat images downloaded from GloVis, in WGS 84 (EPSG 32634) coordinate system. I need to geometrically correct them to S_JTSK (EPSG 5514). Usually, georectification is done ...
1
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2answers
44 views

Tasseled Cap Transformation on MODIS in GRASS

I would like to know how to perform a Tasseled Cap Transformation on MODIS, in GRASS. I've found this https://searchcode.com/codesearch/view/19063909/ but I don't know if this has been tested. I'm ...
1
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0answers
31 views

Clustering the WGS84 point features (projection transformation aspects)

My question is quite trivial and was discussed many times before (like here) but in our case it has the confounding extra requirements... The list of sparsely distributed 2d point features is stored ...
1
vote
2answers
213 views

Vector affine transformation in QGIS2

In QGIS 1.8, I can transform my point layer with the plugin "Affine transformation". So, this plugin don't exist in QGIS 2.0. Do you know a method to simply translate (i.e : X -> X+30000) in QGIS 2 ? ...
1
vote
1answer
28 views

Geographic -> UTM Raster Rectification

I'm trying to use an image overlay in KML / Google Earth as the basis for adding extra info and returning this to Google Earth. In my utility app I can specify a rectangle to give me the ...
1
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0answers
31 views

How use DataFrame Geographic Transformation User Interface with ArcObjects?

I am bringing data from SQL Server into ArcMap with ArcObjects as a Query Layer. If I do this manually, a 'Geographic Coordinate System Transformations' UI pops up. I would like the same thing to ...
1
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2answers
100 views

Transforming and Projecting Shapefiles in R & ArcGIS for Desktop?

Perhaps this is an issue with one of my original data sources, but I've searched extensively to address this problem both through ArcGIS and R. I've got 2 separate sources of a county layer SourceA ...
0
votes
0answers
24 views

Precision loss when transforming coordinates systems in GDAL (vector layers)

Anybody knows the order of magnitude of the error introduced when transforming coordinates using GDAL? More specifically, I would like to know if significant error is introduced when the ...
0
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0answers
22 views

Node.js transformation from NAD83 to WGS84

I've used the excellent npm shapefile library to import Canadian electoral districts into MongoDB. Here's a sample file: http://ftp2.cits.rncan.gc.ca/pub/geott/electoral/2011/fed308.2011.zip Is ...
0
votes
2answers
100 views

Defining a scale number from the Helmert transformation

I know this is more bit of a cartographic issue, but maybe somebody would be able to help. I have an old map georeferenced to the openstreetmap with 50 identical points. I want to get the scale of the ...
1
vote
1answer
61 views

Problem with Converting XY Coordinates to LatLon

Here is the function that I use to convert from pixel x,y to lat,lon coordinate: public static Coordinate imageToWorld(Dataset gds, int x, int y) { double[] adfGeoTransform = new ...
2
votes
1answer
59 views

PROJ4 / PostGIS transformations between WGS84 and NAD83 transformations in Alaska

I'm trying to implement the recommended WGS84 - NAD83 transformation for Alaska using PostGIS. This post: Geographic Transformations in Alaska Between NAD83 and WGS84 indicates the proper ...
2
votes
1answer
35 views

Distort image to display on leaflet.js based on known 16x16 point grid

I have an image that is a satellite picture, and with php gd I want to distort it so I can overlay it on a leaflet.js map. To make it a bit more simple, I have a grid of points, 16x16 which bind the ...
2
votes
2answers
113 views

Mercator: scale factor is changed along the meridians as a function of latitude?

"In Mercator projection the scale factor is changed along the meridians as a function of latitude" How to calculate the Mercator scale factor as a function of the latitude in decimal degrees ? ...
1
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2answers
65 views

Accurate local map projections

Is there a map projection that can accurately represent reality at a local area, i.e. when transforming the map could I choose an area that I care about accuracy and allow distortions elsewhere? Like ...
3
votes
2answers
110 views

Determining closest representation of polygon as collection of points+radii

Have a bit of a tough question, which I realize there may not be an easy solution to. Figured what better place to ask. I'm attempting to transform a polygon into a series of arbitrary points with ...
1
vote
1answer
54 views

Why are my points being flipped or mirrored when I convert from DMS to DD?

I have a collection of crash data that provides latitude and longitude in degrees, minutes, and seconds that I'm converting to decimal degrees using: (degrees + (minutes/60.0) + (seconds/3600.0)) ...
0
votes
0answers
48 views

Offset WGS84 linestring based on pixel values

I would like to split up some roads based on their driving direction. For this, I need to offset the roads 2 pixels to the right, in the direction of the linestring. I have the coordinates in WGS84 ...
1
vote
0answers
32 views

Geodjango transform introduces large errors

Apologies for the possibly naive question. I'm trying to understand how Geodjango (running on PostGIS) deals with coordinate transformations, and am experiencing some unusual behaviour. Let's say I ...
1
vote
1answer
90 views

Translate coordinates in GeoJSON export

I am wondering if there is a way to apply a translation in coordinates for a GeoJSON export. Currently, there are negative coordinate values in my export, which I cannot have. I am trying to use ...
1
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0answers
25 views

EPSG1612 transformation [closed]

I have survey data for contacts listed as eastings and northings - I need to overlay this onto PNG files but the location is quite far north - How do I apply EPSG 1612 transformation to the UTM Zone ...
0
votes
2answers
54 views

How to set a coordinate transformation GRID

Does anyone know how to set a coordinate transformation in qgis so I can measure the distances in meters or kilometers? If anyone has a clue, would be just great. Thanks!
1
vote
1answer
59 views

Rotating markers for points in Tilemill along direction of a way

I have designed a simple marker to represent pedestrian crossings, which in OpenStreetMap data are represented as nodes (points) along the way (line). I want to rotate the marker to follow the line it ...
1
vote
2answers
74 views

Any difference between EPSG:3003 and EPSG:102091?

I am working on QGIS 2.2.0. The PRS I am working on is Monte Mario / Italy zone 1 (EPSG:3003), with the following parameters: PROJCS["Monte Mario / Italy zone 1", GEOGCS["Monte Mario", ...
1
vote
1answer
71 views

Shifting a CAD file from ATS77 MTM 5 to NAD83 CSRS UTM 20

Looking to make the coordinate system shift in ArcMAP (for Nova Scotia) between ATS77 MTM 5 and NAD83 CSRS...NTv2 file?
1
vote
1answer
106 views

ArcGis: Rotated grids and cell size

I am using ArcObjects, namely RasterGeometryProc, to apply rotation on grids. The transformation works fine. However, when looking at the grids properties in ArcGis, the cell sizes has changed. ...
3
votes
1answer
86 views

Help with “projected XY to screen xy” conversion algorithm?

I'm trying to convert coordinates from any given coordinate system (be they the coordinates of a graph figure or a map, meaning they can span across both negative and positive values across any of the ...
2
votes
2answers
53 views

How to replicate ArcGIS coordinate transformation with ogr2ogr?

I need to be able to replicate with ogr2ogr a coordinate transformation that was executed in ArcGIS for Desktop. Both ArcGIS and ogr2ogr are based on EPSG standard definition. There's not only one ...
0
votes
1answer
66 views

Find AB_CSRS.gsb for NAD_1983_TO_WGS_1984_8 Transformation

I am trying to change my WGS84 data to NAD83 for Alberta data. My research tells me that I need to use the NAD_1983_TO_WGS_1984_8 Datum Transformation which is in the AB_CSRS.gsb. I can not find this ...
1
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1answer
64 views

Can I define a transformation between 2D and 3D in Geotools?

I'm using Geotools, and I need to convert coordinates between 2D and 3D coordinate reference systems. I recognize that there's no universally-correct way to do this: 2D -> 3D means "making up" a Z ...
1
vote
1answer
123 views

Rotating the coordinates of a layer by 90 degrees

I have got a dwg file with the plans for a building, with rooms and everything. (There's been some samples taken inside the building which I want to display.) Now, since it's of a building, the person ...
2
votes
1answer
59 views

ArcGIS: How to affect graphics in a MXD by a geographic transformation?

Our GIS users have been using graphics to mark things in their map documents. By graphics, I mean circles, rectangles, lines, text, etc. that can be drawn into data view by using the Draw toolbar. We ...
2
votes
1answer
53 views

How to apply Log Transform to Flow Accumulation?

I have run a flow accumulation for a DEM that I'm working with. I'm trying to apply a log transform because I've heard it could give a better visual representation. How would I go about doing this ...
2
votes
2answers
75 views

How do I transform a raster image to one with rounded corners (cylindrical to pseudocylindrical)?

I've been working with the altimetry data from topex.ucsd.edu/WWW_html/mar_grav.html Was having difficulties extracting the data, so I wrote a simple tool to do that. Creates a bitmap form the data ...
0
votes
0answers
41 views

WGS 84 Transformation issues with ArcGIS and Global Mapper

I have rasters, need to be geo-referenced in WGS 84 datum with Lat/Log (degree). I have geo-referenced using Global Mapper, which we usually used to use, because of its user friendly. Got a vector ...
-1
votes
2answers
435 views

Convert geometry to latitude-longitude using PostGIS ST_Transform

My table has a geometric field, in EPSG:3857, of type point. I need the latitude and longitude, in EPSG: 4326, of each point. Could someone give me a valid example of how to use ST_Transform().
0
votes
2answers
54 views

Transform coordinates from NOAA

I use data from NOAA for some analysis in R and I want to transform coordinates to EPSG:54004 or something useful. There is something what they write about their coordinates. ... POS: 29-34 ...
0
votes
1answer
43 views

How to resolve a 'Received NULL pointer' ArgumentOutOfRangeException for OSGeo.OGR.Geometry.TransformTo?

I am attempting to project a geometry using the GDAL c# bindings and I'm getting a ArgumentOutOfRangeException ('Received NULL pointer') exception on the Transform methods of Geometry. I'm also ...
0
votes
1answer
57 views

QGIS batch affine transformations

I have multiple polygon and line shapefiles on which I would like to apply a translation so I was wondering if it is possible to batch process them (maybe with graphic modeler ?) or do I have to ...
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 ...
3
votes
2answers
468 views

How to detect MGRS/UTM zone?

I posted a similar question on StackOverflow, but I thought I'd check here as well. I am developing an open-source library for converting between coordinate systems, and I've run into a wall. I want ...
0
votes
0answers
68 views

Is it possible to apply affine transformation (translation) to raster image?

Is it possible to move/translate a raster image in QGIS 2.2 (without using georeferencer) just like it can be done with a shapefile ? If not, alternatively can this be done with ArcGis?
2
votes
1answer
247 views

Geographic Transformations in Alaska Between NAD83 and WGS84

I have done a ton of research on the most accurate transformation to use in mainland Alaska to convert between the NAD83 and WGS84 datums, but I just can't seem to find a definitive answer. ArcMap ...
0
votes
1answer
223 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 ...
1
vote
0answers
41 views

Transformation of OGR style data

I have been using GDAL/OGR in a project and it is going quite well. I have been re-projecting data from various source formats into a single CRS (using the C# bindings), but one issue I have come ...
1
vote
2answers
64 views

How to figure out the SRID of a point by comparing it to another point with known SRID?

I have a set of store locations defined in the coordinate system of Bottincarto, which I need to display on Google Maps iOS. Here is an example of coordinates for Notre-Dame-de-Paris: 600926 ...
1
vote
1answer
354 views

Using Affine Transformation to expand polygons in QGIS

I have a shape file, and I'd like to grow each feature by 13.7% or 14%. The program crashes every-time I try to use affine transformation. Any recommendations? I don't have a license for ARCgis. ...