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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1answer
121 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
712 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 ? ...
0
votes
0answers
33 views

Creating hierarchy of Feature Elements in MapForce

I use FME to translate SQLServer tables into gml document. In FME, I make one-one connections (every feature type produces new feature type in output). This document is not 'structured' as I want. ...
1
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0answers
96 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
109 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)) ...
1
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1answer
288 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
vote
2answers
78 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 ...
1
vote
0answers
36 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 ...
1
vote
1answer
213 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 ...
6
votes
1answer
254 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
3answers
79 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
2answers
161 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", ...
2
votes
1answer
202 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?
3
votes
1answer
187 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 ...
0
votes
1answer
159 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
vote
1answer
122 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 ...
0
votes
2answers
144 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 ...
2
votes
2answers
96 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 ...
2
votes
1answer
149 views

How to surround a Polygon object with a corridor of specified width?

I'd like to build a corridor surrounding a polygon, so that the corridor's outer bounds all have the same distance to the inner bounds. Like this: I've made this lousy graphic in Paint, since I ...
2
votes
1answer
83 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 ...
1
vote
1answer
510 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
2answers
133 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 ...
-1
votes
2answers
3k 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
92 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
101 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 ...
2
votes
1answer
124 views

Bad calculations with Colombian projection (EPSG:3116)

Solved, reading mail-archive I can understand that there is a conflict between: gt-epsg-wkt-9.2.jar gt-epsg-hsql-9.2.jar I tested removing each one, with 'hsql' I get the same wrong result, but ...
2
votes
1answer
103 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 ...
1
vote
1answer
111 views

PostGIS transform geometry with long crs

How do i transform a geometry to a new geometry with a crs like urn:ogc:def:crs:EPSG::25832 st_transform(geom,integer srid) obviously doesn't work since my srid is a string found a solution ...
3
votes
1answer
714 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 ...
1
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0answers
69 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 ...
2
votes
1answer
1k 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. ...
3
votes
2answers
107 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: ...
1
vote
1answer
160 views

QGIS 2.0: move basemap by hand in order to achieve overlaying with a point layer

I am an environmental engineer and the aim of my QGIS 2.0 project is to visualize the results of a sewage water system inspection. In a first step I included the hoppers from a csv file and added a ...
1
vote
1answer
293 views

How to automatically transform between base layer and vector layer in OpenLayers

I have a simple example on http://jsfiddle.net/29bsw/ I have a map with an OSM layer as base layer and an additional vector layer. The projection of the map is defined as EPSG:900913 and the ...
0
votes
1answer
110 views

How to get from Lat/Lon to this format?

I have twitter data with coordinates such as: [-7.2377761, 112.73091137] I'm working with a python geo library called osgeo. The sample code indicates creating a point like this. point = ...
3
votes
1answer
140 views

How can I carry out a reliable coordinate transformation for point data?

I have ArcGIS 10.0 with ArcGIS Server (AGS) 10.0. Due to a known bug in the AGS geometry service we cannot carry out coordinate transformations with AGS 10.0. Our Internet client therefore does not ...
0
votes
0answers
39 views

QGIS layer only displays when I uncheck on-the-fly transformation

I have a layer that covers the stats of Indiana that has the following Layer SRS: +proj=utm +zone=16 +ellps=GRS80 +towgs84=0,0,0,0,0,0,0 +units=m +no_defs It will not display unless I uncheck the ...
1
vote
1answer
179 views

QGIS with CH1903/LV03 and WGS84 layers

I have a few CH1903/LV03 layers (lake, river and the country border of Switzerland) and a layer in WGS84 (two points of two cities, Vaduz and Bregenz). On-the-fly-transformation is activated but ...
2
votes
1answer
119 views

Problem while Reprojecting

When I try to transform geometries from SRID 2321 to 4326, the transformed coordinates are swapping. Why is this happening? Below are the details Source SRID - EPSG:2321 Source Data Projection ...
2
votes
2answers
170 views

Problems with transformations in ArcMap

I have files projected in British National Grid. After I have transformed them into WGS_1984. I noticed that if I were to transform them back to BNG the original would not match the new. Is there a ...
2
votes
1answer
182 views

How can I transform Real-time Local position system coordinates into GPS/WGS84?

I have a local coordinate system built with Ubisense sensors and tags (it is a real-time locating system used to automatically identify and track the location of objects or people). The local ...
4
votes
1answer
595 views

Why is tiff different in epsg 3857 and epsg 900913 in gdal

When I transform tiff from 4326 to 3857 and from 4326 to 900913 in gdal, I get different result(when display in Qgis) eventhough these two projections(3857 and 900913) should be the same. What is ...
0
votes
1answer
2k views

From GCS_WGS_1984 to UTM WGS 84 zone 33N

I was doing my project and i had to transform shapefile from bessel to gcs_wgs_1984. that went fine. Now I have to put it again to projected coordinate system. Please could someone help me transform ...
1
vote
1answer
207 views

FME: how to extract the coordinate of the North West corner

In an FME translation from a polygon geodatabase feature class to a DGN I am trying to place a label in the top left corner of a box. I have tried using CoordinateExtractor to find the coordinates of ...
1
vote
1answer
204 views

Buffer Zip Region Polygon with GeoTools

What I want to achieve is to buffer a zip region geometry with a distance in meters and than get the coordinates of the new (expanded) polygon. The original geometry polygon is parsed from a kml file. ...
3
votes
2answers
363 views

Is there a vector affine transformation tool 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
2k views

Trasformation from ECEF to ENU

I am trying to transform a local vector rECEF from ECEF coordinate system to ENU coordinate system (rENU) where ECEF = earth-centered earth-fixed coordinate system ENU = East, North, Up coordinates, ...
1
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0answers
35 views

Geocentric Coordinate Transformations [duplicate]

I have a geocentric coordinate for the position of an object; I am trying to write a function where by an objects position changes with respect to time - moves across the surface at a constant ...
0
votes
1answer
98 views

Transformation data austria - slovenia

can anyone please help with fitting together these 2 shape-files? many many thanx https://www.dropbox.com/s/saa9yp7ecg1qxh1/Grenzen.rar
1
vote
1answer
221 views

proj4js not convert y

Proj4js.defs["EPSG:2322"] = "+proj=tmerc +lat_0=0 +lon_0=36 +k=1 +x_0=500000 +y_0=0 +ellps=intl +units=m +no_defs "; Proj4js.defs["EPSG:4326"] = "+proj=longlat +ellps=WGS84 +datum=WGS84 +no_defs"; ...