Tagged Questions

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

learn more… | top users | synonyms (1)

2
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2answers
101 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 ...
1
vote
2answers
93 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 ...
0
votes
1answer
409 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 = ...
1
vote
1answer
126 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 ...
0
votes
1answer
65 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 ...
0
votes
0answers
64 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 ...
1
vote
0answers
36 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 ...
1
vote
0answers
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 ...
1
vote
0answers
96 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 ...
0
votes
1answer
191 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 ...
0
votes
0answers
40 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 ...
0
votes
1answer
35 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 ...
0
votes
0answers
54 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. ...
1
vote
1answer
66 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 ...
0
votes
0answers
20 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 ...
1
vote
1answer
155 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 ...
1
vote
1answer
96 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 ...
1
vote
1answer
48 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 ...
0
votes
0answers
81 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 ...
1
vote
1answer
88 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. ...
1
vote
0answers
102 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
votes
1answer
52 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 ...
0
votes
0answers
39 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 ...
2
votes
1answer
36 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)?
1
vote
2answers
138 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 ...
1
vote
1answer
106 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. ...
8
votes
2answers
384 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?
2
votes
1answer
59 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 ...
1
vote
1answer
63 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 ...
1
vote
1answer
91 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 ...
2
votes
1answer
52 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 ...
0
votes
1answer
61 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 ...
1
vote
4answers
251 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. ...
2
votes
1answer
48 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 ...
1
vote
0answers
45 views

Problems with projections in QGIS 2.2 on a Windows Vista? [duplicate]

I use QGIS 2.2 on Windows 8, and the same QGIS 2.2 has been installed on a computer with Windows Vista. On the Windows 8 everything works just fine, but something is wrong on the Windows Vista. All ...
0
votes
1answer
66 views

calculate distance between points crossing the antimeridian

How can I calculate the distance between two points (lon/lat) if any of the points exceeds the antimeridian (+-180 longitude)? Im using the distVincentyEllipsoid {geosphere} to calculate the shortest ...
4
votes
0answers
28 views

Projecting polygon when calculating its area? [duplicate]

I have a broad range of polygons (in vector format and in SpatialPolygonsDataFrame class), some going east-west, others going south-north, while even others span polar regions or very large ranges as ...
5
votes
1answer
143 views

Azimuthal Equidistant - 40,000 Km range

I've been looking at making an azimuthal equidistant map. There are several web sites that offer to make one, based on my location, but they all have the same problem. They assume my antenna rotates ...
0
votes
1answer
73 views

How does Arc projecting data without spatial reference?

I have a raster file downloaded from here. When I load it into ArcMap, it says the data is missing spatial reference, and that it can be drawn in ArcMap but not projected. Nevertheless, using the ...
1
vote
1answer
205 views

How to create polygon that goes over +/-180 (dateline) in ArcMap?

I want to create a polygon feature that will go through the dateline (180 long.) in ArcMap. I am using WGS_1984_Web_Mercator_Auxiliary_Sphere (WKID: 3857) for my data frame and my polygonal feature ...
3
votes
2answers
190 views

ESRI projection to SRID?

I am looking at MapX and MapY coordinates. The docs say they are "truncated State Plane coordinates: NAD 1983 State Plane Louisiana South FIPS 1702 (US Feet)." I am trying to reproject into a common ...
0
votes
2answers
144 views

Help, I have 10,000+ .shp files covering 3 UTM zones with unknown projections

I was handed a ton of property files with no projections attached but was told they are all in UTM zone 21S. Well once I merged them all together and projected them I realized that the data covers 3 ...
2
votes
3answers
149 views

Geodesic measurements for short distances throughout US?

My ArcGIS experience has been limited to working on large-scale maps with planar projections. I'm moving to a project in which I want to calculate the distance between pro sports facilities throughout ...
0
votes
0answers
94 views

TileStache : Unknown geometry type in geoJSON file

I'm currently trying to set up a TilSstache server on Ubuntu 12.04 to serve some GeoJSON tiles from a shapefile/JSON file (administratives boundaries) for a web mapping project using the Leaflet ...
3
votes
0answers
50 views

Is it possible to render tile-based web mapping projects in any other projection than web mercator?

Web-mapping technology has to a large degree adopted the web-mercator projection as the standard projection for displaying geographic objects with interactive map-clients. This is due to many factors ...
0
votes
0answers
26 views

Add a raster specifying the projection in pyqgis

I would like add an raster but I want to specify the projection. If I do : qgis.utils.iface.addRasterLayer(url,layerName) QGIS ask me to specify the projection. I want to this with python. How I ...
0
votes
1answer
94 views

Scaling x,y coordinates in proj4

This question was asked before, but without answer. Let's say we have mercator map with given resolution (for simplicity in centimeters). Now let's get coordinates of (lat,lon) = (50, 15): $ proj ...
1
vote
1answer
61 views

Why are some layers saved with custom CRS while others use the appropriate EPSG code?

I have a number of .shp's that I have converted from EPSG 4148 to CPNO27. Some have come out perfectly and others revert to EPSG 1000007. I have checked and the only difference between the two is the ...
0
votes
0answers
15 views

Getting EPSG:4326 WKT data for use in Drupal Geofield [duplicate]

As I understand it, EPSG:3857 is measured in "meters" and EPSG:4326 uses latitude and longitude. In Drupal, geofield seems to want to store "EPSG:4326" data using the WKT widget -- even though the ...
0
votes
2answers
149 views

Projection problem? — OpenLayers, Drupal, and MapBox

I've installed OpenLayers in Drupal 7 and created a view that pulls geofield data for a "Geography" vocabulary (states, tribes, and U.S. jurisdictions) and shows points on a map that I'm storing on ...