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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problem in scale of projected raster

I have a shapefile (my basin limit) and one raster file that I projected it to the shapefile coordinate system and set its cell size to 1000m(area=1Km2). my basin area is 5400 Km2 and it should ...
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52 views

projections Basemap and pyproj

I am struggling to understand the projections using pyproj. for now my question is to understand the results of projection operations I have following coordinates that I project on x,y lon = ...
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39 views

Can I edit coordinates within an edit session and reproject without reloading the data

I have one lat/long to correct. I edited within my table, saved edits, and now when I project using the Project tool the point stays on my map in the same position. Do I need to reload my data from ...
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30 views

Applying distance/area dependent procedures in geographic coordinates over large areas?

I'm currently doing some niche modelling with data in geographic coordinates spanning all of Latin America. I am using R for my analysis. Some of the tasks I have to perform are area/distance ...
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29 views

Classic United Kingdom Projection?

When you visit a classroom in the United States and see a map of the contiguous states on the wall, it's usually in NAD83 Albers Equal Area with the central meridian right at 96 West. Is there an ...
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38 views

Project one layer in qgis using projection CRS of another layer

I am using QGIS 1.6 and have imported a set of latitude, longitude points from a csv file as a layer. I also have another layer from a shape file. When I go to layer->properties for the second layer I ...
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38 views

cs2cs works one way but not the other

I am trying to build a short program using cs2cs that will work on any windows pc I copied cs2cs.exe and proj.dll to a seperate folder When i run this to convert israel tranverse mercator to decimal ...
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64 views

gdal read whole geotif band into vector

i have another c++ GDAL question. I try to read alle elevation data out of an GeoTiff file into a c++ vector so that i can get elevation at x,y like this: vector[x][y]. I also like to use this data to ...
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41 views

Mapnik projection for rectangular coordinates

I am trying to use mapnik to render indoor floorplans and am having a little trouble figuring out the SRS projection. I have geoJSON that represents the floorplan. The coordinates are just cartesian ...
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42 views

50m x 50m grid around the world

I'd like to subdivide the earth into a grid of approx. 50 x 50 m cells (big database, I know). To make it more complicated (and fun), I also need to be able to determine to which cell a given set of ...
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3answers
79 views

Defining custom projection using baseline survey coordinates

I have CAD data that I need to incorporate into a GIS analysis. The CAD data does not have a defined projection, but the drawings include a table of survey baseline points. I need to know if I can ...
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526 views

Changing layer extent to decimal degrees?

Using ArcMap or ArcGIS 10 ... In the photo below, you can see my extent is in meters while my projected coordinate system is in decimal degrees. How can I convert my layer extent to decimal degrees? ...
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179 views

Is there any Google Maps-like zoomable world map, but with an equal-area projection?

Whenever I look at Google Maps at a global or polar area, the projection hurts. Is there any web service with a zoomable world map, that uses an equal-area projection — preferably pseudorectangular ...
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42 views

Why are Google Mercator and UTM rotated towards each other?

Being a self-taught GIS user, I struggled a while before getting the grips on map projections. But now this: because I like to use OpenStreetMap as a background layer for orientation, I have saved my ...
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1answer
60 views

How to find Latitudes and Longitudes of projections of the vertices of a rectangular plane below earth's surface? [closed]

I want to find out the latitudes and longitudes of projections of the vertices of a rectangular plane inside the earth's surface. I know dimensions of rectangle, angles of orientation and latitude and ...
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122 views

which map projection should be used for global map with geography and human demographics

I am working on a project to try to identify the most threatened populations (on a global scale) of having a limited access to freshwater. I want to compare those most at risk currently and then add ...
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148 views

Adding a custom projection to the epsg.properties

I have created an entry at www.spatialreference.org of a customized .prj file. http://www.spatialreference.org/ref/sr-org/7973/ I'm trying to add the generated geoserver entry to the EPSG.Properties ...
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614 views

How to use Google Maps projection with GeoDjango/PostGIS

I am building a web service with GeoDjango which involves user submitted events including a location. I created a model field for my location using django.contrib.gis.db: location = ...
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156 views

OpenLayers Plugin with on-thy-fly-transformation causes wrong coordinates

I am using the OpenLayers Plugin with the maps from Google Satellite. In Qgis I have chosen on-the-fly-transformation into WGS 84. But the WGS 84 coordinates in Qgis are now 0.15 degrees further E ...
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93 views

Copy .prj file into QGIS projection folder

I want a custom projection used in ArcGIS be available in QGIS. I have the .prj file copied out of a ArcGIS folder (containing different projections). Now, I want this file to be added into QGIS. Is ...
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89 views

km measurement in qgis with EPSG 4326

I'm struggling with a small issue. I'm working with the master version of QGIS and I have some layers loaded in my project. All the layer are in 4326 projection and the on the fly option in NOT ...
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37 views

Problem with projection in meters with ArcGIS 10.1 [duplicate]

I hope you can help with the following problem. I have a shapefile and want to project it using a projected coordinate system with meters as unit. What I did was to change the projection from ...
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37 views

Get XY in different projection without changing data frame using python addin [duplicate]

I been searching for a way to use this http://forums.arcgis.com/threads/49273-getting-xy-from-mouse-click-using-python tool but print the XY in different coordinate system like WGS 1984 (decimal ...
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124 views

Creating custom projections with Proj4

I'm reading into how to customise projections with Proj4 - specifically to achieve tilted projections such as the example below (from vis4.net) The Proj4 literature is pretty heavy going and having ...
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272 views

Using Fiona to write a new shapefile from scratch

I am new to Fiona, and trying to wrap my head around reading a csv file and writing out an ESRI shapefile. I have most of it down, but am missing two things; (1) defining the projection/spatial ...
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54 views

Assign a particular projection for un-projected raster/vector files in a folder/sub-folders

We are having 1000's of raster images/vector (shp,tab,dxf) files in a folder/sub folders. Is it possible to check the projection of those and if it is an un-projected one? WGS 1984 has to be ...
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40 views

Political world map texture?

What is correct name of texture and/or projection, which is suitable for 3D engines? I want to apply world map to 3D sphere, but a variety of images found by Google makes me thinks that some of them ...
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58 views

Cause of MODIS Reprojection Tool errors?

I have installed the MODIS Reprojection Tool (mrt) and it says the installation completed successfully but it does not mosaic my images properly. However, there seems to be some projection errors. ...
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163 views

Difference between 2 projections?

I have osm.xml file where projection is defined as follows: Map background-color="grey" srs="&srs900913;" minimum-version="2.0.0"> n settings.xml file projection is also set there as: <!ENTITY ...
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69 views

List the projection & datum of all the files in a folder

In QGIS/GRASS, is it possible to list the projection details of all the shp,tab,dxf files in a folder ? We are having 100 - 150 files in too many folders. We would like to create a table of Proj ...
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23 views

calculation precision during projection transformation

I am using wgs 84 base tiles, and the tile is not rendered as image but with geojson format. I try to draw them in the tile according to the data. And the geometry of the returned feature is lng and ...
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226 views

Openlayer plugin in QGIS, error in projection 3857 Pseudomercator

I'm using QGIS plugin Openlayer to set the background of Google satellite under my vector layer. However, even if I project my layers as EPSG 3857 (the default and only possible projection for ...
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123 views

How to project vector data in QGIS 2.2?

I'm running QGIS 2.2 on Ubuntu 14.04. Trying to project data gives me a hard time right now. The last time I did that was in 2.0 and I basically changed the projection by saving the data as a new ...
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77 views

QGIS Digitizing in Cartesian

I have a client, that needs some geological maps digitized (polygons) in a Cartesian grid. It would be a basic, square grid with North up, and coordinates in x and y. Some of the maps will need to ...
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102 views

leaflet.js ImageOverlay projection bug

We are trying to display a image over the leaflet map using "ImageOverlay" layer, but it does not work according to expected. In Google Maps works perfectly. Apparently Leaflet just stretches the ...
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130 views

Importing a DEM in ASCII format into Arcmap - Projection issues [closed]

I've been trying for the last couple of days to import an ascii grid file into Arcmap. However, I'm really battling to project the data. Can anyone please assist? It would be very much appreciated. ...
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123 views

Calculating closest distances in meters/kilometers given lat/long coordinates?

I am using ArcGIS 10.2 for Desktop. I have a shape file containing points worldwide with lat and long, and another world map polygon file whose Geographic Coordinate System is GCS_WGS_1984 and Datum ...
2
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1answer
67 views

Valid values of mollweide projection in QGis

i just imported a vectorlayer (without any reference points) to qgis as mollweide projection to save it to longlat. What i am wondering about is a mathematical problem: Not every x,y coordinate on the ...
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44 views

Raster projection problems

How would I go about specifying the following projection in Arc and QGIS? After defining this, how would I then go about changing the spatial reference to ESPG 27700? The following are the details of ...
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1answer
41 views

Hölzel projection - prj.file

Is there a prj-file-defintion available for the Hölzel-projection? (http://dl.maptools.org/dl/libproj4/manual.pdf#page=58, page 58)?
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210 views

How to fix shape file projections

I have a project with several shape files. The files overlapping however. I have to go to unusable extents to even see the file on the same screen. I have tried using to project to as suggested here ...
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1answer
168 views

Why doesn't LeafletJS complete the conversion when re-projecting to Spherical Mercator?

When I use the Mapbox Leaflet pre-packaged Projection class SphericalMercator to project a lat/long coordinate into EPSG:3857 I have to multiply the result Leaflet provides by the earth's radius. ...
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407 views

How to get a “classical” globe projection

I have a shapefile of the world continents in EPSG 4326. To what reference system do I have to reproject my file to get a projecting like this globe below?
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70 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 ...
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1answer
70 views

Geoserver Reprojection Results in Northerly Shift Compared to GDAL

I have data in a postgresql data store in EPSG:2163 and am displaying that using OpenLayers in EPSG:3857. This results in a ~25 km northerly shift when displayed either in QGIS or OpenLayers. To ...
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116 views

My class using ogr to calculate distance is returning incorrect results away from the equator

In an answer to this question ustroetz kindly provided some sample code for use of ogr to do lat/lon distance and point in polygon calculations. I've created a Python class based on his example to do ...
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1answer
55 views

Is there general Earth Projection in ArcGIS for Desktop?

I'm starting a new personal project and I need a little bit of helping on setting it up. First off I'm trying to determine the area of a rectangle that is 1 mile in width and the circumference of ...
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70 views

Hand-written coordinates from a Garmin NUVI

I've been asked to map point data that was collected in the field by manually writing down the coordinate from a Garmin NUVI 1490 LMT. They were put into a spreadsheet and sent my way which I was ...
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4answers
361 views

Which projection should I use to get my WMS service to work?

All of my shapefiles have exactly the same WKT. Using http://prj2epsg.org I have verified that EPSG:3059 has the same parameters as WKT definition of my shapefiles, so I'm using 3059 in my mapfile. ...
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1answer
56 views

Why this two datasets don't match?

I have a postGIS database in SRS 4326 (WGS84) with several Europe layers working well, but when I load a shapefile projected to the same SRS with QGIS, the layers don't match. To explain it better ...