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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63 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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3answers
192 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
93 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 ...
2
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1answer
60 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. ...
2
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1answer
110 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: ...
2
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2answers
109 views

No prj file output from qgis:reproject

I'm trying to reproject a vector layer using the 'qgis:reproject' algorithm in the processing/sextante module of QGIS, from Python. This kind of works, but the .prj and .qpj files created after ...
2
votes
1answer
416 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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1answer
416 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
66 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. ...
2
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2answers
208 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& ...
2
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1answer
90 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
106 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 ...
2
votes
2answers
245 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 ...
2
votes
1answer
844 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
votes
1answer
135 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 ...
2
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1answer
107 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): ...
2
votes
1answer
317 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 ...
2
votes
1answer
209 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
200 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!
2
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2answers
241 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 ...
2
votes
1answer
978 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: ...
2
votes
1answer
86 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. ...
2
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1answer
346 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 ...
2
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1answer
170 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 ...
2
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2answers
322 views

C++ coordinate class that automates projection?

Can anyone point me to a C++ class for representing coordinates that automatically handles projection transforms? What I'm thinking of is something that would allow me to create vars that incorporate ...
2
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1answer
185 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
votes
2answers
847 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
votes
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
votes
1answer
609 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
votes
1answer
175 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
429 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
369 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 ...
2
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1answer
83 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
727 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
votes
1answer
847 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
votes
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
votes
2answers
164 views

How to convert a NetCDF file to GeoTIFF using GDAL

I have a NetCDF file which contains data for the number of rain days in the UK. I'd like to convert it to a GeoTIFF, but can't get GDAL correctly georeference it. See dumps from gdalinfo below. I ...
2
votes
1answer
102 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
votes
1answer
95 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
75 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
votes
1answer
89 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
44 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 ...
2
votes
1answer
116 views

Waterman Projection in ArcMap

Anyone have any idea how to create (or where to find) the Waterman "Butterfly" projection in ArcMap?
2
votes
1answer
38 views

Change the projection at runtime (OpenLayers)

How do I change the projection on an existing Map object? I'd like to allow a user to switch between cylindrical (EPSG:4326) and custom-declared projections with the click of a button.
2
votes
1answer
88 views

Why does same image in two ArcGIS ArcMap configurations show different extent numbers?

I would like to get hear from you about the situation I am seeing here. What It got my eye was that when I download an ASTER from Reverb/ Echo from USGS website. At work, I load my ASTER file to my ...
2
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1answer
100 views

Georeferencing of a vector data

I am evaluating QGIS with a view to visualize and manage geological exploration data. The information is currently stored in different local coordinate systems that I am looking to overlay with ...
2
votes
2answers
131 views

Older British Geological Survey geology maps of Kenya; need complete projection information

I have several geologic maps of Kenya produced by the BGS circa 1993. Noted on each map is the following: Projection:-Transverse Mercator Spheriod:-Clarke 1880 (modified) That's great, but that ...
2
votes
1answer
64 views

When is a projected length calculated via a pythagorean distance more accurate than an ellipsoidal length?

I'm using spatialite 3.0.1 with the following test data (in EPSG: 4326): Name astext(geometry) ---------- -------------------- Belitsa POINT(23.563 41.947) Malko Tarn POINT(27.533 ...
2
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1answer
391 views

Blank MapServer WMS image at low zoom levels in OpenLayers

I have an OpenLayers map using OSM as the baselayer with several layers coming from MapServer via WMS. The OL map is in EPSG:3857 and my mapfile (and shapefiles) are in EPSG:4326. In my mapfile I ...