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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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 ...
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1answer
111 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 ...
2
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1answer
49 views

does Pseudo Mercator Projection causes problem while clipping rasters

I tryed to clip a Raster file using an ESRI shapefile using gdalwarp command, but i always get an empty output file or a wrong clip with wrong location. this the command bellow: gdalwarp -dstnodata ...
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2answers
80 views

Measure areas, lenghts in specific regions (Australia, Sout East Asia)

I'm in need to find a suitable projections to measure correctly areas and lenghts for 2 areas of interest. I want to measure both factors for: 1) First region Australia & New Zealand (1st ...
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2answers
112 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 ...
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3answers
409 views

How to calculate Polyline length in kilometres without changing projection from WGS84 (using ArcObjects)?

I have Road (polyline) feature class and I wish to find those roads whose length are greater than 500 kilometre. The feature class projection is in GCS_WGS_1984 and I do not want to change the ...
2
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2answers
132 views

Plotting a certain range in azimuthal projection using ggplot2

I would like to limit a map to a particular range of values (i.e. northern hemisphere) under an azimuthal or orthographic projection in ggplot2. When I set ylim, I receive an error message that ...
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1answer
92 views

Miller cylindrical projection - central meridian

I'm new to projections topics and I've got a question that may be silly, but I hadn't found answer so far. I'm trying to use Miller's cylindrical projection for converting osm lat/lon to x,y values. ...
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1answer
242 views

Qgis OSM and layer projection problem

I am using QGIS 2.1.0, and trying to import my vector layer(parcels) with OpenStreetMap layer. My vector layer (parcels) use EPSG 31277 coordinate system. This is the definition for EPSG 31277: ...
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1answer
932 views

Canvas Units to Degrees, Minutes, Seconds

I am using the WGS 84/UTM coordinate sysytem. When I go to > Project Properties / General / Canvas Units to Degrees, Minutes, Seconds my coordinates are wrong. I am using QGIS 2.0.1
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1answer
99 views

Albers Conic versus State Plane Zone in terms of accuracy

I'm trying to determine if an Albers Conic (Alaska Albers) is suitable as a projection for a corridor 800 miles long by 50 miles wide, that goes from the north coast of Alaska to the south coast. ...
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3answers
387 views

Is GeoServer getting coordinate output in GeoJSON WFS wrong?

When I do a WFS request to GeoServer and specify the SRS like this: http://myserver.com/geoserver/wfs? service=wfs& version=2.0.0& request=GetFeature& ...
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1answer
101 views

Find projection from dataset

I have a dataset that I have pulled from a MaxSea 3d database. I am trying to figure out what projection is used, so I can transform and use the data. I have tried following this guide ...
2
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1answer
122 views

Wrong object size after projecting spatial data from one coordinate system to another

I am having problems reprojecting items in ArcMap 10.1 from British National Grid To WGS84. (WKID: 27700 Authority: EPSG to WKID: 102100 Authority: ESRI) All Polygon Layers I project [I use Project ...
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2answers
334 views

What's the correct transformation for Lambert Conformal Conic for Wyoming?

I am a newb in QGIS. I have loaded QGIS 1.8 (Lisboa) and practicing with a number of maps for portions of the state of Wyoming. My maps are mostly in UTM 12N NAD 27 & NAD 83 some are in decimal ...
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1answer
1k views

QPJ files on ESRI software

We have some GIS data, which was converted from AutoCAD dwg to TAB using mapinfo, then converted to shapefiles as that's what we are required to create. Editing the data fields was done in the shape ...
2
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1answer
193 views

Which BC Albers should I use and is there any difference?

I was about to calculate the area of some polygons and before I did I did some research. I found that the area of the polygon will be represented in the units of the projection used. So I did some ...
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1answer
129 views

Determining the transformation between a satellite image and long/lat

I'm trying to overlay some data onto a satellite image of the UK. The image is a hi-resolution version of the image below (originally from dundee university): ...
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1answer
451 views

Area calculation: Albers Equal Area vs Pseudo Mercator

I have a question concerning area calculations in South-East Asia for West-East range that goes from India to Eastern Malaysia and a North-South range from Northern India to Indonesia (xMin,yMin ...
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1answer
250 views

Problems with NAD27 projection in QGIS

I have some data that is in NAD27, but I am having a hard time displaying it in QGIS. I think that the problem is with the CRS. I cannot seem to find the correct NAD27 option. The closest one seems ...
2
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1answer
255 views

Convert map to use space oblique mercator projection

I have a map document in ArcMAP which I want to convert to using Space oblique mercator projection, but not sure if ArcMap supports it. Any hints on how to achieve this? thanks!
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2answers
308 views

projection issues from ArcGIS to Qgis

I am pretty new to ArcGIS and Qgis. I have loaded some geometry data in Qgis from my postgres database, then I have also loaded the same data in ArcGIS. Then from ArcGIS i have created a shapefile ...
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1answer
1k views

How to setup leaflet map to display a WMS layer in ESRI:102012 projection?

I have a WMS server that serves layers in ESRI:102012 projection. http://spatialreference.org/ref/esri/102012/ It accepts GetMap requests with srs=EPSG:102012 parameter. My goal is to display a map ...
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3answers
2k 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: ...
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1answer
93 views

Need software to read geo information from tif

I am trying to verify the lat/lon and ECEF values that I have determined for a very specific and unusual situation (a geotif file), and it would be great if I could find some software to read them. ...
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1answer
393 views

Uploading unprojected shape files using GeoServer REST API

I have a number of shapefiles that lack the .prj file. I'm able to upload them to geoserver using the rest api. However, I'm unable to serve them after upload. Which brings me to the question as to ...
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1answer
187 views

How to add FP_WGS_84_IBCAO_Polar_Stereographic projection to QGIS?

I have a GeoTiff image that is projected (see below) I would like to add this projection to the list of CRS in QGIS. Can someone help me do this? Thank you very much in advance!!! Francis ...
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1answer
203 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 ...
2
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2answers
925 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 ...
2
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3answers
1k 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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1answer
1k views

Quantum GIS Reproject a projected coordinate system with rotation

I have two shapefiles:- one in WGS84 Z30S and one in a custom, system based, projection. I need to convert the custom projection into WGS84 Z30S. I have a set of parameters including a shift in X and ...
2
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1answer
688 views

What is wrong with this Proj4 transformation?

I'm implementing support for WMS maps in my company's software. Servers return a list of projections their maps are available in, but our software only displays data in WGS84 (lat/lon or UTM), and ...
2
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1answer
181 views

OpenLayers.Control.DrawFeature Accuracy problem

When i draw a polygon using the OpenLayers.Control.DrawFeature then i export that polygon to KML using OpenLayers.Format.KML. Though, when I open it in google earth there is a big difference between ...
2
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1answer
464 views

How to determine area of pixel in meters with GDAL and Python?

I have a raster loaded in Python using GDAL bindings. I'd like to be able to determine the area of a pixel in meters although I'm not confident that the projection is in meters. On this page I see a ...
2
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1answer
448 views

How to generate a grid of horizontal equal-area rectangles in a Mercator projection?

I'm new to GIS so pardon my ignorance and bear with me. I'm generating a grid relative to a LonLat point. To make the cells all equal area, I'm creating it in 2163 projection. The problem is that when ...
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1answer
86 views

Coords not aligning

The two shp files are not aligning like they should (note the img). The layer and the two shps all have the same coords - NAD_1983_StatePlane_North_Dakota_North_FIPS_3301_Feet The surface shp came ...
2
votes
1answer
746 views

How to provide transform information to openlayers on Image layer

I would like to include an overlay raster layer into my OpenLayers map. I've pre-transformed the image into the correct projection (EPSG:900913) and saved as a png using the gdal_translate command: ...
2
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1answer
889 views

Geowebcache does not displaying map tiles in EPSG:900913 from a remote WMS server

I connect Geowebcache to a remote WMS service through their Getcapability request by adding the url in geowebcache-servlet.xml document. Geowebcache demo page displays the list of wms layers from ...
2
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1answer
1k views

Conversion of any projection to latlong using proj4 string

I am using a tool which uses proj4 lib to project maps. I have a set of xy coordinates to be converted to latlongs with that tool. as I have the source projection string say +proj=aea +datum=NAD83 ...
2
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2answers
28 views

matching coordinate systems by transforming and projecting

matching coordinate systems of all my data (transforming, projecting) My data uses the GCS_Bessel_1841 coordinate system. Would there be any inaccuracies if i would transform it to DHDN 3-Degree ...
2
votes
2answers
26 views

Overlaying misaligned DGN file in ArcGIS for Desktop?

I received a DGN file, I believe created in Bentley 8, and there is a bit of a misalignment problem. The dgn, when overlain on a Bing Maps aerial or NAIP image, shows up about 20 m or so off. I'm set ...
2
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1answer
38 views

Error reading large virtual raster with rasterio: “Cannot invert degenerate transform”

I've created a virtual raster using gdalbuildvrt, which covers a large extent (England) at a high resolution. The data is fairly sparse, focused around the coastlines with no files covering inland ...
2
votes
2answers
98 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 ...
2
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1answer
58 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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3answers
163 views

How to use PROJ4 to reproject a file

Unfortunately, GDAL does not support a particular projection I am trying to achieve (the ob_tran rotated pole projection), so I am trying to use PROJ4 to convert a geotiff file to the projection I ...
2
votes
1answer
159 views

How to synchronize the marker's rotation field with the angular distortion in the map projection

I'm Using QGIS 1.8.0 to plot a global dataset showing the positions of aircraft in flight. The data I have are .csv files with three columns: Latitude, Longitude, and angle of travel. I assign ...
2
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1answer
142 views

Viewshed analysis and coordinate systems ArcGIS 10.1

I am trying to run a viewshed analysis and I've downloaded DEM data from the UK ordnance survey (Landform-panorama). Since the data is in ASCII format I have created a seamless raster mosaic (and used ...
2
votes
1answer
132 views

Choosing correct proj4string in R for a set of points

I was given a set of points which I eventually will overlay with a polygon shapefile in R. The issue is that the person who provided me with the points did not give them to in long/lat coordinates but ...
2
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1answer
169 views

Change coordinate system of a WMS service

I have a WMS service that is projected to UTM/SAD-69. My workspace is in WGS-84 with no projection. I want to change the coordinate system of my WMS service. Is it possible in ArcMap 10.0? The wms ...
2
votes
1answer
64 views

Misaligned GADM shapefiles and the NE dataset

I am very new to using GIS programs, so please excuse me if this is a trivial question. I'm having the following problem: When adding a GADM shapefile layer for Uganda onto the Natural Earth set of ...