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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2answers
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Waterman butterfly projection in Mapnik

Like the title says, how would someone configure Mapnik to use the Waterman butterfly projection ? Otherwise, what other tools would be able to render using this projection ?
20
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5answers
2k views

Simplifying geometries (generalization)

What are the recommended ways of simplifying geometries? Keeping in mind projections, and simplifying state geometries for example. I've heard about converting to an 'equi-distant' projection that ...
2
votes
1answer
286 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 ...
9
votes
1answer
785 views

An example Tissot ellipse for an Equirectangular Projection?

I am trying to calculate distortion of an equirectangular projection via Tissot indicatrices. I have tried following the directions on this post (among other things) but it is beyond my understanding ...
7
votes
1answer
3k views

Leaflet and EPSG 4326 Projections

UPDATE: LEAFLET fixed support for EPSG 4326 (LL84) in the latest betas: https://github.com/Leaflet/Leaflet/issues/1207 Leaflet says it supports EPSG 4326 (Plate Carree, aka ll84) projections. I think ...
4
votes
1answer
650 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 ...
5
votes
2answers
1k views

How do I specify a CRS for a fictional game map in QGIS?

I am about to start playing a steampunk RPG game called The Iron Realm, which uses a fictional world map. I have recently started using QGIS v1.7 and have no real experience with GIS sysstems. I have ...
4
votes
1answer
3k views

R - Plotting shapefile with geographical (raster) data

Over the last few days I have been trying to plot a shapefile over data loaded into a data.frame within R. It should be a view of radar precipitation with an overlay of the country borders from a ...
2
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2answers
442 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 ...
4
votes
2answers
155 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 ...
3
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2answers
387 views

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

I have a shapefile with the following .prj file: ...
2
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2answers
397 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 ...
1
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1answer
399 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 ...
-1
votes
1answer
639 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 ...
3
votes
2answers
813 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 ...
1
vote
2answers
341 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 ...
1
vote
1answer
758 views

TileStache + OpenLayers TMS - Tiles are rendered disorderly

I newly turned to TileStache to render Mapnik tiles because of the caching option. Before, I was using Mapnik python bindings only and it was working perfectly. Now that I use TileStache, the tiles ...
2
votes
1answer
232 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
votes
1answer
299 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 ...
3
votes
1answer
37 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 ...
2
votes
1answer
690 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: ...
0
votes
1answer
162 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
votes
1answer
236 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 ...
0
votes
1answer
505 views

Why do points shift when reprojected from WGS84 to a state plane coordinate? [closed]

We have a Trimble unit we use to collect equipment. We collect the data in WGS84 and differentially correct it and then reproject it to a state plan coordinate system. The points always shift the ...
10
votes
2answers
1k views

Where did the polygons go after projecting a map in QGIS?

I'm fairly new at GIS know-how, but I've run into a problem with a projection of a world map. I have a shapefile of all countries I downloaded from Natural Earth. After projecting it into a ...
3
votes
1answer
217 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: ...
2
votes
1answer
761 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
2answers
565 views

Data points Imported into QGIS are in the middle of ocean

I'm new to QGIS and tried importing some GTFS data in the CSV format (stops.txt). The project CRS, base map CRS and GTFS CRS have all been set to Google Mercator, but the points that are supposed to ...
2
votes
1answer
90 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.
3
votes
2answers
394 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 ...
0
votes
2answers
975 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: ...
4
votes
1answer
396 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 ...
2
votes
2answers
225 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 ...
0
votes
0answers
120 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 ...
1
vote
2answers
289 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
votes
1answer
546 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 ...
51
votes
7answers
4k views

What strategies, criteria, or rules to use for selecting coordinate systems?

What strategies, criteria, or rules do you use for selecting coordinate systems for (a) storing, (b) analyzing, and (c) displaying GIS data? (I humbly offer my reply to a related question ...
2
votes
1answer
303 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 ...
2
votes
1answer
622 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 ...
1
vote
2answers
373 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 ...
1
vote
1answer
238 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 ...
1
vote
0answers
24 views

Implementing day night functionality [duplicate]

I want to implement day/night functionality on world map i.e there will be dark layer showing countires having night now. This world map could be creaeted through ESRI or SVG map.I want to ...
2
votes
1answer
443 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
359 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 ...
3
votes
1answer
439 views

QGIS display does not reflect projection

I have slight experience with ArcGIS, but am new to QGIS. I'm trying to set the projection of my map, and I understand that this is done by altering the CRS (coordinate reference system) of each ...
2
votes
3answers
1k views

What is the projection of an Android Location class instance?

What is the projection of a Location object returned from the LocationClient by a class implementing the LocationListener interface with a fused provider in the Google Play Services SDK? For example, ...
3
votes
0answers
840 views

Fortifying re-projected shapefile for ggplot2 in R

I have a shapefile of US county boundaries which I got from the NHGIS. I can load the file using the rgdal package and see information about it: library(rgdal) shp_1860 <- readOGR("shp", ...
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1answer
667 views

OpenLayers using GoogleMaps layers: issues with setCenter and transform

Past week or so I have been doing everything in just OpenLayers and has been going great: been using markers, vectors, bringing in json data via php, and some ajax. Everything has been in one layer ...
1
vote
1answer
165 views

GeoTIFF without projection?

I have encountered a GeoTIFF raster files with EPSG:4326 (WGS84), i.e. no projection defined! Is this normal? I would expect raster to be in Projected Coordinate System. Raster is a grid of pixels so ...
0
votes
0answers
387 views

openlayersplugin qgis 2.0.1

I have installed qgis 2.0.1, great thing... but.. open layerplugin doesn´t work proper. When I try to load two different open layers I get the answer "could not draw google satellite because:" Also ...