A map projection is any method of representing the surface of a sphere or other three-dimensional body on a plane

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Change vector projection in Openlayers

I have added vector layer to map: vactorTest = new OpenLayers.Layer.Vector("Editable Features", { strategies: [new OpenLayers.Strategy.BBOX(), saveStrategy], projection: new ...
2
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2answers
401 views

How to shift the Map a little bit?

I'm having trouble with two maps, both UTM33N/WGS84. They should be exactly on top of each other but there is a slight shift between them of probably a few hundred meters or so. I Tried to adjust ...
1
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2answers
573 views

Re-initializing OpenLayers Map with different projection

Is it possible to re-initialize OpenLayers Map with a different projection ? Scenario: OL Map with projection 4326 is created, along with click, measurement, drawing handlers. A button to switch to ...
2
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2answers
661 views

LonLat Points to Grid of Polygons in PostGIS

I'm going to preface this with it's my first time using PostGIS. I'm starting out with a 5 km x 5 km grid cell in which I know the center point lon/lat (SRID=4326). I'm trying to create a polygon for ...
1
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0answers
398 views

Conversion From Transverse Mercator To Longitude & Lattitude

I have to transform (7-parameters datum transformation) coordinates from northings & eastings to lattitude & longitude. Following are details of source coordinate system(i.e. northings & ...
1
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1answer
606 views

Reprojecting a shape to UTM33

I still have trouble reprojecting shape files :( I would like to reproject it to UTM33N / WGS84 (EPSG 32633) I think the projection of the shape might be Pulkovo 1984/ Gauss-Krüger Zone 4 (EPSG ...
3
votes
1answer
3k views

How to correctly specify coordinate system?

Using QGIS v. 1.9 (1.7 does not seem to be available for Ubuntu Linux 12.04), do the following: Create new project, specify coordinate system by clicking on button in bottom right hand corner, ...
3
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2answers
1k views

Display two layers with OpenLayers at once

How can i display two layers with diferent projections at once? For example i have layer with EPSG:70076 and OSM layer.
5
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3answers
1k views

Convert Nasa's Blue Marble into a cubic projection

I'm looking for a free tool to convert the cylindrical projection map of the Earth's surface that you can get from Nasa (under the Blue Marble project): ...
3
votes
2answers
429 views

How do you change the prime meridian of a map?

I am working with the Natural Earth world map as a SHP file, but when I try to change the prime meridian (PRIMEM) of the coordinate system ...
5
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3answers
2k views

Using arcpy what is the most efficient way of projecting a selection from a large data set?

I have a large data set X(x1-xn) from which I must select consecutively the attributes A(a1-an) from X.fieldsSRC or X.fieldDST and project the selections. I have a functioning arcpy script that does ...
2
votes
1answer
187 views

Is there an arcpy boolean check for whether an EPSG or prj is supported by arcmap?

I'm writing a tool and essentially I found out that arcmap defaults an epsg to 0 if it sees that the projection is not supported against the predefined projections.
3
votes
1answer
235 views

Automate database conversion from NAD83 to Web Mercator

A NAD83 database is updated daily while a Web Mercator clone is only update when time is available. Looking to automate this process of Copying Layers Projecting them to Web Mercator Placing in ...
4
votes
2answers
3k views

How do I get the distance meter value between two geometries in PostGIS?

I have a simple question about calculating distances in PostGIS. I would like to get the distance between two geometries. I am using this sid : 4269 in meters what i am doing now is this : ...
0
votes
1answer
953 views

Projecting from State Plane (Oregon) into UTM (zone 10)?

I have an air photo with the following xy coordinate system name: NAD_1983_StatePlane_Oregon_North_FIPS_3601_Feet_Intl and the following in the description field: Projection: ...
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0answers
412 views

How do I use Proj4js or other technique to make custom map projections with google.maps.Projection?

I'm using Google's Projection class to try to convert my map projection from the default spherical mercator to something like Lambert Conformal Conic. I was previously adapting the code from this ...
1
vote
1answer
4k views

How to change the projection of a UTM-georeferenced raster in Quantum?

I have a project file in Quantum which contains some shapefiles and rasters that are properly georeferenced. However, I have started using GeoTiffs which are in UTM - WGS84 that don't seem to be ...
1
vote
1answer
897 views

When I import polygon kml layer, how do I change projection and offset to correct for GMT wrap?

I created a polygon in Google Earth and saved to kml. After importing as a vector layer, where the polygon crosses the prime meridian, the polygon wraps around the world. So far, I have figured out ...
2
votes
2answers
6k views

How to create custom coordinate system in ArcGIS Desktop?

I have a series of control points with xy coordinates in both NAD83 UTM and in a local grid. How can I go about creating a new projection file in ArcGIS 10 for the local grid?
12
votes
1answer
999 views

How to define Winkel Tripel in proj 4.8.0?

I have QGIS with proj 4.8.0 installed. I'd like to add Winkel Tripel projection which seems to be defined as +proj=wintri But that definition string does not work. Is this a bug in my proj version, ...
19
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7answers
1k views

Spatial reference for dummies?

Can anyone recommend a good reference or tutorial that explains the principles of spatial references, projections, and coordinate systems? We are a small team of programmers working with GIS ...
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0answers
150 views

How to show an array of 2d points/polygons in Polymaps (Cartesian coordinate system)

I need to display these 2d points/polygons (Cartesian coordinate system) on Polymaps with GeoJson layer. I do not use the other layers. Do I need to convert xy coordinates to the lat lon? If so, how? ...
2
votes
1answer
3k views

How to convert decimal degrees units to km in R?

I am trying to figure out how I can transform my unit of length from decimal degree to km when I import the following simple ArcGIS polygon shape. Ultimately, I would like to have this information ...
3
votes
1answer
2k views

How to perform datum transformation in ArcGIS server REST API exportmap

I have a ArcGIS server 10.0 mapcontext in one projection (swedish grid sweref99 TM) which uses its own datum, also named Sweref99 . When I use the REST API's map service export function I want to ...
4
votes
2answers
675 views

Is it possible to automatically set CRS of Rasters from PRJ file?

I am trying to learn my colleagues to display measured data (ASCII) in maps relatively easily. I can prepare project, color and symbology style for the point layer and background map. I also found ...
1
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1answer
330 views

Looking for help identifying projections and reprojecting

Hi there at the new forum, I'm still struggling with projections in qgis. The "Vogelschutzgebiete" reprojection worked. But these ones seem to be tougher: ...
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0answers
60 views

What projection is this [duplicate]

Possible Duplicate: QGIS - Hell of time with CRS and vector intersect The tax assessor parcels layer I referred to in my first post gives this as its projection: +proj=lcc ...
10
votes
2answers
365 views

How do I determine the projection of a paper map?

If I'm reading a paper map how do I determine what projection was used to draw the map if such information is not explicitly labelled on the document? Online it is easy to find resources (for ...
3
votes
2answers
1k views

Image tiling math

I've been looking at MapTiler for the logic on how to render an image as tiles on a (google) map. Instead of storing the single tiles locally in a folder structure I want to use Djatoka. I'm able to ...
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0answers
559 views

Geoserver tiles mismatch

I tried to get WMS tiles from geoserver like /geoserver/gwc/service/tms/1.0.0/layername@EPSG%3A4326@png/15/19142/9530.png or with another projection ...
3
votes
1answer
442 views

How would I go about re-projecting the Blue Marble raster maps into a robinson projection using free tools?

I would like to convert the NASA Blue Marble maps into a robinson projection.
3
votes
3answers
2k views

Rendering a shapefile with a custom projection in GeoTools

I have an image, a shapefile, and a method which can translate an x/y pixel location from the image into a latitude/longitude point or vice versa. I'm trying to use Geotools to render the shapefile on ...
2
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0answers
103 views

raster data expressed as percent

I downloaded NDVI greeness data from the USGS Integrated Vegetation Mapping Viewer. In the metadata it says that visual greenness values range from 0 to 100. My data is from the period ending 3/5/12 ...
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vote
2answers
359 views

Geowebcache re-projection

I have one layer (raster geotiff image) published in geoserver with EPSG: 3011 projection. But I want this layer in EPSG 4326 projection for use it in google API web application. I have searched on ...
0
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2answers
105 views

Need Image with Sweref99_1800 projection/coordinate system

I need third party image tiles (probably world imagery) under sweref99_1800 projection and coordinate system (EPSG 3008). I found this link ...
2
votes
3answers
2k views

Why are the tile coordinates different in Google maps and Google earth?

I have a .NET application that typically uses the standard Google Maps JavaScript API V2. Within this application I am using a GTileLayerOverlay to add my own custom dynamic tile layer. function ...
7
votes
2answers
3k views

How is EPSG:4326 data 'projected' in a 2D map?

I like to think I'm relatively well-versed in datums, projections, and coordinate reference systems, so if this is a stupid question I will suffer eternal shame. OpenStreetMap data is stored in WGS84 ...
0
votes
0answers
85 views

How to change the projection of the base layer of a tile map?

Normally, we change projection of vector data for displaying it over a Google base map. Is it possible to change the projection of base image tiles map? If yes, how we can do that? Any reference or ...
15
votes
2answers
1k views

Which world map projection allows comparing countries by shape and size?

The Mercator projection increases scale along with the latitude. Greenland seems larger than Australia, when in fact it is much smaller. The equal-area projections however stretch shapes away from the ...
5
votes
1answer
3k 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 ...
27
votes
3answers
27k views

Layers with same coordinate system should align/overlap but do not?

I put 4 different layers into my ArcMap document, but only one of them will show up on the map! I should be seeing the other 3 layers as well. When I do a Zoom to layer, I can see one layer, but I ...
20
votes
1answer
6k views

How to define new custom projections in QGIS?

I'm trying to define a projection in QGIS. I want to add North America Albers Equal Area Conic. From the spatialreference site I copied the proj4 line: +proj=aea +lat_1=20 +lat_2=60 +lat_0=40 ...
2
votes
1answer
1k views

How can I transform GCS_WGS_1984 to GCS_North_American_1983?

I need to convert a GCS_WGS_1984 data set to NAD_1983_UTM_Zone_14N. What transformation should I use?
2
votes
4answers
3k views

OpenLayers transform EPSG 27700 coordinate to Google 900913

Community, I'm currelty capturing my mouse click event and trying to transform the coordinates into Long Lat. I need to get at the Long Lat as strings so I can build a url and throw it at Google ...
1
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0answers
216 views

I am getting a blank layer preview from geoserver after Quick Exporting my shapefile to postgis and then getting postgis to point to geoserver [closed]

What could be the potential problems? Looking at the layer's data fields/form the one thing that isn't filled is the Native SRS and its source, but I have already passed in the projection info as it ...
6
votes
1answer
262 views

What's a robust strategy for displaying 3D map data for navigation?

3D map data, specifically the kind you see on GPS units, or more recently on smart phones, almost always features a 'HUD' like view, which I'm trying to implement in an application of mine. I have ...
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vote
1answer
644 views

Converting distance between nautical miles and degrees using ArcObjects?

We have a certain functionality developed that: Will check for a tolerance value (this input is given by the user as NM); Buffer a polygon by that value (all polygons are in WGS-84); Iterate through ...
13
votes
2answers
5k views

API documentation for Gdal/Ogr with C#

I want to assign projection to shapefile in my web C# application, for this i am using Gdal/OGR/OSR C# bindings and add osr_csharp.dll and ogr_csharp.dll references. But i am facing some difficulty ...
2
votes
1answer
521 views

Possible to use Google Earth to generate “skyline” planes?

I was really interested to notice that my city appears to have gotten the 3D Buildings treatment on Google Earth. I am trying to figure out how I might these 3D buildings to generate 'skylines' for a ...
6
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5answers
3k views

How to add a projection to a Shapefile using open-source tools?

I have been given some shapefiles WITHOUT a projection. So I need to add the projection in order to display it on google map. I found the projection information I need at ...