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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135 views

Shapefiles from Nationalgrid without a .prj file - what projection are they in?

Im working with these shapefiles: http://www2.nationalgrid.com/uk/services/land-and-development/planning-authority/shape-files/ They show pipelines & electricity grid of the UK. They do not ...
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2answers
150 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
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2answers
138 views

How do I set a CRS when it isn't listed in QGIS? (Mac, not PC)

I want to work with a shapefile that is in a Coordinate System that I can't locate in QGIS for Mac. When I load this shapefile data, it shows up fine, on-the-fly has generated the CRS data most likely ...
2
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1answer
180 views

Axis of rendered shape files not showing numbers that are latitude and longitude

I am using rgdal to render some shape file. The first is a set of building zones from NYC Open Data. The second is the NYC coast line from OSM. The Zone files seems to generally render an X axis ...
2
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2answers
212 views

Spatial Join of 2 line layers offset by minuscule amount

Let's say I have 2 line layers (green & red, in the image below) and I need to transfer attributes from one layer (red) to another (green) by doing a Spatial Join. The layers are identical, but ...
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2answers
446 views

Variation of algorithms to find point from another point with bearing and distance

There are several algorithms to calculate distance between two latitude/longitude points. Haversine Hubeny Lambert-Andoyer Vincenty's formulae for inverse problem But there are not so many ...
2
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1answer
130 views

Reprojecting Natural Earth dataset to World Eckert I

My question is connected with QGIS 2. Could anybody explain me how I ought to reproject the Natural Earth dataset there in order my world map to look correctly? When I strive to reproject these data I ...
2
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1answer
913 views

GeoTools and PostGIS with ESPG:3857

I'm trying to use both PostGIS and GeoTools with the same ESPG:3857 projection, however, it looks like the projections in PostGIS and GeoTools differ. This is what I have in PostGIS: PROJCS["WGS 84 ...
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374 views

Map projection lat, lon to pixel?

I'm trying to find the concave hull of a lat, lon pointset but when I project my points on my map it doesn't look like expected. I've tried a lineare projection and a spherical projection. My data is ...
2
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1answer
252 views

QGIS Georeferencer, unexpected transformation, and GCP placement

Im trying to get the sample map which i believe to be EPSG:3112 into QGIS and geo referenced. In my screenshot, on the right is the raster in georeferencer with the points i have added. On the left is ...
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1answer
466 views

How do I project a Azimuthal Equidistant global map into a circle in QGIS?

I'm fairly new to QGIS/GIS stuff in general, so I apologize if this is too simple of a question, and I'm just bad at finding my answer. I have a shapefile of all the countries in the globe I ...
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2answers
1k views

How can I use GDAL to batch define a projection?

I have a fodler with 1500 ECW rasters, no spatial reference information defined. Can I use GDAL to batch define a projection for all 1500 in the folder?
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890 views

How to understand GeoTIFF tags?

I'm trying to understand GeoTIFF info, but not getting far. For instance, using listgeo with one file I can get this output: Geotiff_Information: Version: 1 Key_Revision: 1.0 ...
2
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2answers
188 views

Mapping elements in a warehouse

I am new to GIS. For a small project I want to map elements in a warehouse and want to find the location of the elements later (e.g. nails are located at x,y). Now I am wondering what kind of ...
2
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1answer
159 views

Do FeatureLayers reproject their features to adapt them to the map projection?

I'm working with the ArcGIS Flex API. For example, ArcGISDynamicMapLayers do reproject their data in order to make it in the same projection as the map. Do FeatureLayers have the same behaviour?
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1answer
98 views

QGIS mixing up CRS

I´ve just started working with QuantumGIS for my thesis. I ordered shapefiles with the CRS: ETRS 89 UTM Zone 33N, but QGis layer properties now shows the layer has a different CRS (namely SWERE99 TM) ...
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1answer
178 views

Difference between NAD83 Indiana SPW in QGIS and ArcGIS for Desktop?

It seems ESRI and QGIS don't have the same definition for my most commonly used projection, NAD83 StatePlane Indiana West (US ft). When I create data in an ESRI product the projection shows up in ...
2
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2answers
356 views

How to calculate the surface using Lambert correction?

i'm using lambert conformal conic , so we have distortions along any given parallel , i would like to get the area used to solve this distortion. I have calculated the area using Shoelace formula , ...
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2answers
622 views

How do I import specific Coordinates from Namibia in QGis?

I have a map here with Coordinates from the Schwarzeck Map Datum Format 1903. They have the following format e.g.: y: 41 944,31 x:363 810,71 I want these point to be pictured in QGis... how is it ...
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3answers
3k views

Problem with spatial reference system / shapefile projection

I am new to using QGIS and having some problems getting some shapefiles to project correctly. I am using publicly available shapefiles for New York City municipal boundaries found here: ...
2
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1answer
1k views

Defining datum for Lambert Azimuthal Equal Area and converting to geographic coordinates

I posted this question to a specialised mailing list for spatial data analysis using R here but didn't recieve a response. I am working with shapefiles and rasters in R, and I am unsure if I am ...
2
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1answer
574 views

How to transpose the lat/lon coordinates of a shapefile?

I need X to be Y and Y to be X (switching lat/long) within the polygon shapefile. If it were a point shapefile I know I could simply reverse the lat/long or x/y parameter and import from a table. I'm ...
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3answers
320 views

Are there WMS servers providing maps of UTM zones, actually in the zone projection?

There are lots of EPSG:4326 (lat lon) services out there but if one has to use an UTM projected map as base layer to display utm scenes, are there any WMS endpoints publicly available for that?
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1answer
133 views

Projection Decision

I'm deciding on whether to use a geographic projection (lat/long) or a lambert conformal conic projection for a web servicing project that will use raster, vector, and point data, for queries, ...
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1answer
638 views

Rendering 3D timezones KML on a 2D map

I'm trying to render a KML layer (with timezones) in Google Maps API v3. The KML layer works fine in 3D (in Google Earth), but when I render it in 2D, the timezone lines that meet at the North Pole ...
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1answer
651 views

I have several layers (polylines and polygons) that are of the same area but they don't overlap in ArcMap as they should, what do I do?

For my GIS project for my class, I have downloaded several vector layers from different websites (polyline of the continental divide, a boundary polygon of New Mexico, a rivers and water bodies layer ...
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3answers
3k views

How to change default projection in ArcPad 10?

Is there a way to set a default projection in ArcPad 10? The only way I can tell is by creating a quickProject based on a project that contains a shapefile with the same projection, but that's just ...
2
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1answer
59 views

World map different projection

I want to display something on a world map. I have these shapefiles http://thematicmapping.org/downloads/world_borders.php I want my map to look something like this: or I am using QGis. Is ...
2
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1answer
69 views

How to re-project shapefile to be compatible with Openlayers satellite imagery

The goal: Visualize a map using google's satellite (and projection) using my collected points. Right now I have a shapefile of my collected points from surveying. I created it by adding my csv file. ...
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2answers
40 views

Georeferencing a map image with no precise projection info

I am trying to georeference a map that has meridians and parallels etc. but no projected grid displayed. I can get the coordinates of the meridians/parallels fine, so georeferencing should not be an ...
2
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1answer
34 views

Reprojecting from Wagner VII using QGIS

I have a shapefile in Wagner VII projection (well, the proj4 string really only is: "+proj=wag7 +datum=WGS84 +units=m"). I'd like to reproject it to WGS84 (EPSG:4326) using QGIS 2.6. However, when I ...
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1answer
31 views

Raster origin is incorrect, does not properly overlay with vector in same CRS

Two layers, both allegedly WGS84, one vector layer of the Midwestern US, one raster layer with coverage of the entire US. The vector layer renders correctly (coordinates are correct), but the raster ...
2
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1answer
93 views

How to transform this PostGIS type of projection to EPSG:900913 in OpenLayers?

I have transferred this kind of projection from this type(which I don't what type it is): 010100000054E077E6F8F33640FD87F4DBD7AD4340 to EPSG:900913. I have the points which are in the above format ...
2
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1answer
61 views

Proj4js: Is this correct implementation of Azimuthal Equidistant relative to an arbitrary center?

If I wanted to interpolate points along a Great Circle Arc, it makes sense that either endpoint of the Great Circle is a satisfactory starting place. Next, I suppose I'll need a projection to preserve ...
2
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1answer
190 views

Georeferencing a raster using GDAL and Python

I want to georeference a raster using python and GDAL. My current approach is to call gdal_translate and gdalwarp using os.system and an ugly list of ground control points. I'd really like a way to do ...
2
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1answer
105 views

Proper projected coordinate system for Minnesota for measuring areas

I have seen in ArcGIS many different State Plane systems for Minnesota (location coordinates in WGS84: 44,07 lat/-94,61 long) within the Projected Coordinate system group: NAD 1983 (CORS 96) ...
2
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2answers
59 views

Custom projection problem with proj.4

I have some vector files that come without projection. So I have to define my own projection in QGIS. The information that comes with the data reads as following: Projection: Lambert Azimuthal Units: ...
2
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1answer
432 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 ...
2
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1answer
246 views

Pyproj: converting WGS84 to Robinson

I have a WGS84 coordinate pair (37.7749295, -122.4194155). I have an image that is a Robinson Map Projection of the world. I'm trying to write a python script to locate my WGS84 coordinate on my ...
2
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1answer
43 views

Figuring out what coordinates supposedly using 'NAD31 projection' refer to

I'm working with a GeoJSON file that contains sets of coordinates associated with street corners in the city of Montreal, Canada. The spec sheet of the API delivering those GeoJSON specifies that the ...
2
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1answer
153 views

How to find the projection of an image?

Instead of georeferencing the image and deforming it, I'm trying to find the projection used by the author of the image. I've got tens of these distribution maps to digitize. The idea is to avoid ...
2
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1answer
106 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 ...
2
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1answer
71 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 ...
2
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1answer
45 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)?
2
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1answer
56 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 ...
2
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1answer
59 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 ...
2
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1answer
163 views

gdal2tiles generates small picture inside 256x256 tile

I've used gdal2tiles for generating tiles in number of different polar projections and always experienced the same problem — strange small picture inside normal 256x256 png with the rest of space ...
2
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1answer
65 views

Equal (ish) areas Map Projection at the Tropics

What map projection (non-interrupted) preserves areas well for the entire tropical region? I am thinking of using a Cylindrical Equal Area or a sphere based version of a Cylindrical Equal Area or ...
2
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2answers
62 views

Comparing projections of two datasets when SRID not available

Similar to this question: How to test if two GDAL datasets are in the same projection? However, the above does not cover cases where an SRID is not available. It can often be the case that an SRID is ...
2
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1answer
151 views

How do I set the projection and coordinate system for a TIFF file?

I have a topographic map of California (obtained from CAL-Atlas) as a TIFF file. I tried importing it into QGis, but it displays the map using a pixel based coordinate system rather than ...