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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GDAL - projection from pixels to geo coordinates

I am using GDAL library in C++. On my dataset, I have obtained geo transform with GetGeoTransform to GT array (GCP is NULL). Than I use this values for this equation (Source): Xgeo = GT(0) + ...
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239 views

GDAL/proj4 equirectangular projection coordinate system units assumed by OGRSpatialReference and GDALDataset::GetGeoTransform()?

How do I configure my OGRSpatialReference object to specify an equirectangular projection system http://en.wikipedia.org/wiki/Equirectangular_projection where the affine geo-transform matrix (provided ...
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112 views

QGIS DXF file projection match

I need to use this file on a map but I am not able to match the projection with the others I have, primarily data downloaded from OSM (city of Boston). I read many articles, I have repeatedly tried to ...
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111 views

Projection to use with satellite image from Google Maps / Earth

I'm very new to anything concerning GIS so please forgive me if this question has been asked before, but I assure you, I've been trying to find an answer for quite some time now. Of course it is ...
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2answers
237 views

Calculating bounding box coordinates based on center and radius

I need to calculate a bounding box for osm query. I get coordinates of center of the area (WGS84) and radius (meters). How can I do it? I though about using some kind of projection, calculating ...
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252 views

How to convert WGS84 to UTM when the study area covers 4 UTM Zones: 43- 46?

I'm working in ARCGIS 10.2, my area of interest falls in 4 UTM zones 43,44,45,46 equally distributed so i can't use the option of majority of area's UTM zone. Since i need to carryout varies analysis ...
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2answers
104 views

How do I get the projection of an LAS file using liblas?

I am using the python api of liblas to read/write las files. I would like to get the spatial reference information of the las file using liblas, but have been unable to figure it out. Can anyone ...
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90 views

Trying to set NAD 1983 EPSG 102631 in QGIS

I was able to find the right coordinate system online NAD 1983 Alaska But now I don't know what to do. I can't find the coordinate system on QGIS. When I choose the one I think is correct it warps ...
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132 views

Equivalence of EPSG:3857 for MapInfo 9.5

I have copy a raster projected on EPSG:3857 with QGIS. I have edit image registration in Mapinfo but there is no projection for EPSG:3857. Do you know the projection who I need to use? Thank you. ...
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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 ...
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77 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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62 views

towgs Definition for European Datum 1950

I am new to all things GIS so apologies for a basic questions. I am trying to specify the CRS of a climatic raster layer in R. It is an equal area projection based on Europe Equidistant Conic and the ...
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150 views

How to display WGS 1984 Web Mercator (Auxiliary Sphere) services in Google Earth?

The basemap services provided by Esri (on ArcGIS Online, Data and Maps for Sever, and the Data Appliance for ArcGIS) use the WGS 1984 Web Mercator (Auxiliary Sphere) spatial reference (WKIDs 102100 or ...
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216 views

Predefined Coordinate Systems missing in QGIS 2

in QGis 1.8 were lots of predefined coordinate systems (national projections). Where have they all gone in qgis 2.0? I specifically need the Gauß-Krüger-Projections Zone 1 to 5. Is there any plugin ...
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76 views

in python, srs.ExportToProj4() returns an empty string, why?

I have a shapefile with the following .prj file: ...
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3answers
116 views

Creating spatially projected polygon grid with ArcMap

i need to create a grid with 1x1 square kilometres cells in ArcMap. The operation located in Data Management Tools -> Feature Class -> Create Net is almost what i need but in the parameters, i can't ...
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1answer
186 views

My wms vector data overlay on openlayer vmap work fine but on osm img is not rendering

i am try to overlay my India roads vector over an openlayer (http://vmap0.tiles.osgeo.org/wms/vmap0) vmap work fine.but i want to do the sam task over osm(open street map), i am trying many different ...
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1answer
77 views

Problem changing CRS to enable clip function

I have two layers, one point file and one polygon. The point file is in WGS 84 and polygon in NAD83-UTM10. The project CRS is NAD83-UTM10. They project fine with on-the-fly projection turned on. I ...
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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 ...
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1answer
94 views

Problem with projection of layers in QGIS

I'm having a problem with projections in QGIS that i hope someone here can help me with. I have been searching and found other people having the same problem, but have not been able to solve mine ...
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2answers
105 views

Coordinates values change for ArcGIS

I have received thousands of location information like below. X= 10°52.579 Y= 078°38.473 I don't have idea in which format is this, please let me know what is the format of this location and ...
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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. ...
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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 ...
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22 views

Equidistant projection for northern Delaware

I'm just getting started on a long-term project involving northern Delaware. Most of my distances will use great circle distances from the lat/lon, but for a few applications I'll wind up using ...
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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: ...
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149 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 ...
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65 views

Why are Bounding Coordinates not as expected? [closed]

I have a shapefile in GCS_WGS_1984 projection, but the bounding coordinates/Feature extent shows the wrong coordinates in the screenshot below. . I tried to change the projection, by deleting the ...
3
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1answer
55 views

How to get projected centroids in QGIS?

I am trying to get a centroid for several polygons on a global scale, in a way that it would correctly represent the common centre of all the polygons, taking Earth's curvature into account. The ...
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2answers
169 views

Ortho Projection produces artifacts

I`m trying to create a sphere-like view using qgis and the "world from space"-projection http://spatialreference.org/ref/sr-org/6980/ (essentialy an ortho-projection). ArcGIS wraps the shapes ...
3
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1answer
93 views

What are the set of projections that can be accurately georeferenced using polynomial 2?

Background I'm starting with a map from the internet (Encyclopedia Britannica) and georeferencing it using QGIS 2.0.1, I get really accurate georeference solution using polynomial 2 transformation: ...
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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
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81 views

Does ModelBuilder need to use variable to define projection and then re-project?

I am trying to build a Model in ModelBuilder to create two different process raster datasets: One set is to define a raster dataset to set a WGS 84 projection; and then the second set is to take ...
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106 views

How to transform a PostGIS bounding box?

I need to query the bounding box of a table (in WGS 84, srid 4326), and transform it to Web Mercator to be consumed by an OpenLayers map. Currently, I am using this to retrieve the bounding box: ...
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3answers
156 views

How to find and apply reprojection parameters?

I have a data set in one projection, and a shapefile in another, and I am trying to combine the two. I am using Python. I apologize for posting a "help me transform coordinates" question on this site ...
4
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1answer
73 views

How to rotate sphere when using Vertical Near Side Perspective projection?

Situation Data is currently displayed on a globe using the Vertical Near Side Perspective projection with a blue circle as a backdrop. Problem I would like to 'rotate' the globe by altering the ...
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2answers
92 views

Set projection/CRS in map and shapefile to produce buffer

I simply want to create a buffer of a specific size, around a single point. When I create a buffer it uses degrees/ or radians, or whatever, and the buffer is created that covers the whole screen. I ...
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101 views

Geographic Coordinate system and Projected coordinate system [duplicate]

Please Excuse me If I asked a Silly question : When to Set A Geographic coordinate system or projected coordinate system to a Shapefile?
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79 views

Doubt in Field Calculator

I am working in an project.I have a point Shapefile its projection is NAD83(HARN)Pennslyvaniasouth(ftUS)*EPSG3365* when I measure its distance(between two points) it gives me the answer in feet .yes ...
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74 views

How do I Fix Projection Issues in QGIS

I have some exiting shape files that supposedly have a CRS of OSGEO:41001. If I import new data, and set the CRS to OSGEO:41001 they do not align. If I change the CRS of the new layers to ...
3
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2answers
106 views

Calculate distance in QGIS, wrong geographic projection?

I'm trying to do the following: I have 2 shapefiles, one containing all the public schools in NY, another one containing the hotspots in NY (both in points form). Now what I'm trying to do is ...
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How can I improve the resolution of a vector grid made in north pole stereographic projection?

I've been struggling with this for a while and wondered if someone could lend a hand. I have a map which already has sampling points from centroids in a 35x35km grid that was created in north pole ...
3
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1answer
132 views

Coordinate systems and bearings

Ok so I've got a noodle scratcher and want some input before I open my mouth to my higher-ups. I recieved a new boundary description from a surveyor that uses metes and bounds in the form of bearings ...
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1answer
71 views

Heads up digitizing - Polygons overlay differently with two different Satellite images

I have been digitizing building footprints from satellite image using ArcGIS 10.1 . Field data collections is done with the use of four corner point GPS way point. Due to multipath errors, we are ...
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1answer
95 views

OpenLayers overview shows wrong map

i have a problem. I have to implement a map with OpenLayers. As BaseLayer I use an external WMTS-Service, which has the projection EPSG:25832. I want to have an OverviewMap, but the OverviewMap ...
2
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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
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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 ...
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321 views

Stereographic projection of WGS84 ellipsoid on a plane[python]

I would like to ask you for help in following task. What I need to do is to derive local x,y coordinates from latitude, longitude, applying stereographic projection of WGS84 ellipsoid on a plane, ...
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1answer
74 views

Different output from running algorithm in toolbox and from script

I am unable to get the same results when running the qgis:reproject tool from QGIS processing toolbox (QGIS version 2.0.1) as when running it from a Python script (console). In this example I am ...
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72 views

Best practices and examples of web maps of polar regions

I am looking for examples of web maps focusing on polar regions (Arctic or Antarctic) preferably using a polar projection. What could be best practices to follow for such web mapping applications? Any ...
2
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2answers
108 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 ...