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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24 views

Openlayers GeoJSON write not maintaining projections

How do I get GeoJSON.write to maintain the projections used in the construction of the GeoJSON? points.geojson {   "type": "FeatureCollection",   "features": [     {       "type": "Feature",       ...
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1answer
571 views

Equal Area SRID for Australia

Does anyone know the SRID for an equal area projection that is suitable for the whole of Australia? I realize that I could make my own (which I have done) but I am looking for one that is present ...
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1answer
28 views

How to calculate areas for data that covers the whole of Australia [duplicate]

I have a polygon shapefile showing mining areas across all of Australia. I want to calculate the area for each of the polygons however they have been provided in a Geographic Coordinate System ...
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3answers
433 views

Is there projection issue with Natural Resources Canada (NRC) Canada Atlas hydrology data?

I have been using the Natural Resources Canada (NRC) data for various generalized maps but it is not until now when i overlaid higher resolution features obtained from the provincial government ...
6
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1answer
11k views

Transforming GCS_North_American_1983 to GCS_WGS_1984 using ArcGIS Desktop?

I posted Is there projection issue with Natural Resources Canada (NRC) Canada Atlas hydrology data? describing a shift in some of the NRC data (not all). Apparently, this shift has to do with ...
3
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2answers
1k views

Influence of the scale factor on the projection

I'm currently reading documentation about map projections to understand the source code of the Proj4 project. The scale factor is named in a variety of sources I read. This sources explained its ...
3
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1answer
52 views

How do I fix distortions when reprojecting cshapes world maps?

I am using the cshapes package in R as a source of historically accurate country borders. While the default WGS 84 maps plot fine, I would like to reproject the maps. This introduces some distortions ...
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0answers
15 views

Geoserver import does not recognize projection

Using GeoServer 2.8 and the Data importer plugin I can import shapefiles generated in ArcMap with WGS84 geographic coordinates (EPSG:4326) and UTM+WGS84 projection (epsg:32724). As a reminder, ArcMAP ...
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868 views

Using gdal to convert from UTM to equidistant lat/lon

I am getting rather confused with converting a UTM gridded dataset into a equidistant/rectangular latlon gridded dataset. Can anybody help me? I have a UTM set with the following projection: ...
2
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1answer
59 views

GeoServer WMS correct WFS wrong coordinates for line features?

I'm calling my geoserver with WMS and later WFS to retrieve vector data (both times EPSG 4342. All features are correctly rendered in WMS and QGIS, so I'm sure the original data is fine. The original ...
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0answers
37 views

How to test polar stereographic projection for a specific longitude intersection?

I'm writing a library that tests grids defined by map projections for intersections, and am running into an issue implementing the test for polar stereographic and rectangular projections - ...
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1answer
775 views

Transforming between epsg:3857 and Google Maps Tile coordinates

Hio, I used to use a simple python project (https://github.com/hrldcpr/mercator.py) to convert between wgs84 and google maps tile coordinates. This project doesn't have a license, and looks like it ...
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1answer
32 views

Reprojecting Tifs [duplicate]

When I import some geotifs into QGIS, they use a reference of 0, 360. My basemaps are all -180, 180. Both the basemaps and geotifs use the same CRS, WGS84. So the geotifs display starting at 0 on the ...
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2answers
166 views

Add scaleline control to openlayers 3 map with unknown projection

I've a mapguide map display with openlayers 3 like this: var options = { "minZoom": 0, "maxZoom": 100, "center": [mapInfos.center.x, mapInfos.center.y], "extent": [mapInfos.extent.minX, ...
0
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1answer
95 views

Why do pyproj and matplotlib basemap produce different results when they convert my lat-long data into a CRS?

pyproj and matplotlib basemap seem to produce differing x-y values when they convert my lat-long data into the same CRS (such as Albers Equal Area). These x-y values tend to be off by hundreds of ...
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0answers
15 views

change projection for openlayers map with kml file

I use the basic example shown in dev.openlayers.org/examples/sundials.html to display kml files areas, with map.zoomToExtent(kmllayer.getDataExtent()) to auto center and zoom. The problem is that ...
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1answer
1k views

Convert from ITM ref to GPS ref?

How can I convert from ITM ref (Israel new map) to GPS ref and from GPS ref to ITM ref? I need any C# sample code or formula for this. For example: 32.086156,34.769239 = 178364,665948 Or : ...
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0answers
25 views

Is it safe to query for points contained within polygons using a lat-long projection?

I'm querying for points contained within a polygon. All data - both points and polygons - is stored in latitudes and longitudes. Technically I should probably project this data to a suitable local ...
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0answers
20 views

Should I set the projection if the data has already been projected?

I need to plot some data which was produced on a native grid with a lambert conformal conic projection. I need to create a geotiff (using python and gdal) and was wondering how to go about and do ...
0
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1answer
27 views

Ways to make distances more apparent

I have made this map: The intention of the map is to make it clear that the distances is shorter from Luleå than from Rome. As you can see that is not the case here. Which ways are there to make ...
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0answers
41 views

problem with area calculation in QGIS

I encountered a problem in QGIS 2.10.1 when I tried to calculate the areas of polygons in a polygon layer. I followed the instructions here ...
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0answers
83 views

how to set the geotransform using GDAL in python

I am trying to create an image from a numpy array and georefenrece it so that I can import it into qgis. I have the latitude and longitude in degrees for the top left corner of the array as well as ...
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0answers
36 views

How to create raster with origin in degrees and dx dy in metres

I need to create a raster from array. In gdal if i understand correctly i need to specify the top left lat lon for the SetGeoTransform((originX, pixelWidth, 0, originY, 0, pixelHeight)) however the ...
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0answers
24 views

Projected Coordinate System issue using GDAL and qgis when defining x and y

I have a numpy array which I would like to save as GeoTiff using GDAL in python. The array was created using the following PCS in mind: +proj=lcc +lat_1=48 +lat_2=48 +lat_0=48 +lon_0=0 +x_0=0 ...
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1answer
25 views

Get pixel geo info according projection and map extent

I would like to know if it is possible to calculate the geographic coordinates (lat, lon) for a pixel specified by its x/y (top-left) cartesian coordinates in a map image/raster? The datum and ...
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1answer
90 views

On the fly reprojection in QGIS?

I'm new to QGIS and trying to deal with on the fly reprojection. I have three layers : a shapefile in EPSG:4326 a raster in EPSG:3395 that same raster reprojected in EPSG:3857 (with QGIS via the ...
2
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1answer
175 views

Bad calculations with Colombian projection (EPSG:3116) in GeoTools?

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 ...
6
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2answers
264 views

Create a projection to emphasize a given direction in ArcMap?

Suppose one had a dataset (centered on a given coordinate) of lines that were very close together in terms of longitude but also had important turns/bends far separated by latitude. In order to map ...
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2answers
67 views

Coordinates transformation

I have the following data base with information about rainfall for a set of meteorological stations: year station latitude longitude depto municipio date rainfall 1990 11010010 0527 N ...
0
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2answers
101 views

How to convert projected coordinates to geographic coordinates without ArcGIS? [closed]

I'm trying to convert a series of points from Easting Northing to LatLong, I have this working perfectly in Arc but ideally I would like the algorithm to do it through our own system. It is a huge ...
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1answer
32 views

$area calculation doesn't work or wrong projection?

I've been reading the QGIS manual and I've encounter a problem I don't know what to do. I downloaded data from OpenStreetMap and the raster from http://srtm.csi.cgiar.org/SELECTION/inputCoord.asp The ...
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3answers
4k views

Get Lon Lat values from a GEOGRAPHY data type in PostGIS

After storing lon lat values as a GEOGRAPHY data type, how do I retrieve the individual lat lon values? Failed attempt: SELECT id, geog, ST_X(geog), ST_Y(geog) FROM locations; Error: No function ...
6
votes
3answers
2k views

Projecting selection from large data set using ArcPy?

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 ...
51
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8answers
2k views

One dimensional map of the world?

Bit of a strange question but hope this is OK to ask here. Has anyone heard of a '1-dimensional' projection of the world map - that is mapping all the points on the globe to a single line? I was ...
2
votes
1answer
38 views

Issue rendering polygons at global scale when using the Robinson coordinate reference system in QGIS 2.10

I am trying to create a map using the Robinson coordinate reference system (EPSG:54030) in QGIS 2.10, on Mac. I used the 'on the fly projection' feature in the Project Properties. My base layer is a ...
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1answer
62 views

Mapnik tiles have latitude distortion, projection issue?

I'm trying to work out a kink in setting up mapnik-node. My geos are in postgis, and I allllmost have them rendering properly, but my GIS experience is lacking so I can't seem to determine why this ...
1
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1answer
227 views

Openlayers 3 circles from geojson not working with layer tile source different from TileWMS

I am working with openlayers 3 with a layer from mapbox or openstreetmap and I need to draw some circles on it. I am able to print the circles with a view with a projection EPSG:4326, but then I have ...
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0answers
16 views

Google Earth Mapping in Beijing - Why is it shifted? [duplicate]

When using Google Earth Pro, the road network and the underlying imagery do not line up. At first I thought this was a road network issue. However, when I geolocate addresses using the Baidu ...
0
votes
1answer
132 views

Zoom Scale in OpenLayers 3

Need to change the default zoom of OpenLayers 3 to do so adapted scales, type [1: 100000, 1: 50000.1: 25000.1: 10000.1: 1000.1: 500] have seen in Openlayers2 if you can, but at 3 I have not found a ...
0
votes
0answers
116 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 ...
2
votes
1answer
1k views

openlayers display projection

I'm displaying coordinates in EPSG:900913 using ol.control.MousePosition() with OSM. I'd like to convert these on the fly in another EPSG:2154. I call in the header : <script ...
0
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1answer
87 views

layers don't match on OpenLayers

So in my Openlayers 3.9.0 I use Bing Maps and OSM layers, they both are EPSG 3857 var layer = new ol.layer.Tile({ source: new ol.source.OSM({}) }); var bingMapsAerial = new ...
1
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0answers
59 views

Disparity between QGIS and ArcGIS for Desktop georeference results?

I am georeferencing a static map in JPEG format. I would prefer to use QGIS for a variety of reasons. I've never georeferenced with QGIS before, so I may not have the process quite right. I ...
4
votes
1answer
67 views

What projection should I georeference this historical map to?

I'm using ArcGIS. I have a historical map from 1884. It has bathymetry information which I would like to compare to modern bathymetry models with as much accuracy as possible. I don't know what ...
2
votes
1answer
103 views

Adding OpenLayers basemap to a QGIS project changes the CRS to WGS 84 / Pseudo Mercator

I have a QGIS (2.10.1) project that contains several shapefiles, all of which are EPSG:3338 (NAD83 / Alaska Albers). The project property CRS is also EPSG:3338. All of the shapefiles display ...
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0answers
36 views

Geographic Center of Earth centric Projections [duplicate]

This is more a question born out of curiosity than actual needs, but this seems like the right place for it. Based on What is Centroid of all lands of Earth? I was wondering what world maps centered ...
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0answers
27 views

How can I change the projection used by the QGIS Browser preview?

QGIS Browser has no settings in the UI. Is there any file or so where I can define this?
19
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5answers
12k views

Map projection in OpenLayers

I want to overlay some data whose projection is WGS-84 on Google map layer in OpenLayers. But I just can't make them in the right place. I did as follows: map = new OpenLayers.Map('map', { ...
2
votes
1answer
31 views

Why does not equal computing line in `OpenLayers` with `ArcGIS` when i use measure control?

My map projection is: "EPSG:900913" ,Display projection is "EPSG:4326" and units is "m", however does not equal the length is calculated in OpenLayers with ArcGIS, in fact Openlayers show the length ...
9
votes
2answers
971 views

How to determine projection parameters when customizing a projection

I am trying to customize an Albers and a Hotine Oblique Mercator (HOM) projection to minimuze distortion in the region I am analyzing. The region extends from about 51 to 62 degrees latitude, covering ...