A map projection is any method of representing the surface of a sphere or other three-dimensional body on a plane

learn more… | top users | synonyms (1)

2
votes
1answer
833 views

Convert shapefile in NAD27 from meters to decimal degrees to match xy data?

I have a shapefile of a boundary (polygon) that has the following projection: NAD_1927_UTM_Zone_11N Projection: Transverse_Mercator False_Easting: 500000.00000000 False_Northing: ...
4
votes
2answers
1k views

TileCache and Openlayers Problem - Projections?

I have a very known problem, but I can't solve it. I have set the same maxExtents in the config as in the Openlayers init JS. I have done the same thing with the projection (EPSG:900913) and done all ...
2
votes
1answer
108 views

cannot reproject postgis in mapserver

I am trying to set up a wms server using point data in a postgis (v 1.5.1, pgsql v 8.4) database and mapserver (v 1.5.1) (I know these are not the most current versions of anything, but my server is ...
2
votes
0answers
134 views

Projection declaration in dojox.geo.openlayers possible?

I am trying to integrate some maps of my own into the dojox charting demo and I had success in exporting a shapefile (externally, i.e. with my own parser) to the dojo JSON map format. The map is in ...
1
vote
0answers
128 views

adding WMS service to application ArcGIS JS api

I've got map in projection: 4326 (WGS-84) when I try to add WMS layers which is in different projection I always get connection timeout Do you know if I could change WMS projection to set it up ...
7
votes
2answers
851 views

Is the quadrilateralized spherical cube map projection the same as Snyder's cubic equal area map projection?

Is the quadrilateralized spherical cube map projection [1] the same as Snyder's cubic equal area map projection [2]? I know both are equal area polyhedral map projections ( ...
1
vote
0answers
268 views

Adding X,Y data and viewing with existing shape file

Excuse me for a simple question. I have CSV files of X,Y data (in decimal degrees) that I want to add to a map and view with a shapefile of level III ecoregions that I downloaded from the USGS ...
2
votes
2answers
367 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 , ...
2
votes
2answers
344 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 ...
3
votes
1answer
510 views

Get the geotransform in Mercator given a pixel size away from the origin

I have a radar image with the following information: The projection is Mercator (Mercator_1SP in GDAL) The projection origin is 0º lat 0º lon At a given geographic coordinates (e.g. lon=10º ...
2
votes
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 ...
12
votes
2answers
1k views

How to reproject raster from 0 360 to -180 180 with cutting 180 meridian

I have a geotiff raster image that has a coordinate system with longtitudes from 0 to 360. The horizontal center of the image is 180 longtitude. See image below: I want to transform it to EPSG:4326 ...
3
votes
1answer
462 views

How to reproject a raster to Winkel Tripel projection?

I'm trying to project a raster map (in ASCII grid format) from longlat to the Winkel Tripel projection. But I'm running into errors, for instance gdalwarp won't accept the proj-string. $ gdalwarp ...
11
votes
6answers
644 views

Where can I find GIS data to test GIS coordinate operations?

I am trying to find some data that can be used to test GIS coordinate operations from one CRS to another CRS. So far all I have found is the Gold Data set and also various example points in the EPSG ...
3
votes
2answers
2k views

German coordinate system from Lat/Long

I have WGS latitude and longitude for data points near Munich and I'd like to use a grid-type coordinate system, like the Ordnance Survey grids in Ireland or the UK. What coordinate system do you ...
2
votes
1answer
331 views

What coordinate system is this?

I just found a dataset of trees in San Francisco, but I'm unable to determine the system used for the coordinates. Here are some samples: 5998894.045593,2119007.035323 ...
2
votes
0answers
532 views

Help converting projection/coordinates to Google Earth

I'm trying to program a GPS style tracker for a simulation game but I'm having a hard time figuring out how to transform the game's coordinates into Google Earth's. The game's world is flat and has ...
2
votes
2answers
263 views

How to project US States in Transverse Mercator [duplicate]

Possible Duplicate: Layers having the same coordinate system should overlap, but they don’t. What’s wrong? I created two different MXDs, one for City of Tucson and another for US States. If ...
1
vote
2answers
334 views

Recovering Latitude and Longitude from Albers to Compute Distance

I have a shapefile of U.S. counties in USA Contiguous Albers Equal Area Conic. I want to do distance calculations. For example, distances from one county to another. I do not know how to interpret ...
2
votes
1answer
2k views

Import GPX to QGIS with WGS84 [closed]

When loading a GPX-File in QGIS it is not referenced on WSG84. It´s shown with wrong coordinates. Settings are WSG84.
2
votes
1answer
60 views

What is the purpose of having a separate Layer property for sphericalMercator?

The Beginner's Guide to OpenLayers 2.10 says the following: sphericalMercator {Boolean} This property determines if the map should behave as a Mercator-projected map. Setting this to true ...
2
votes
1answer
310 views

What is the expected margin of error for points plotted on EPSG:3857 projection?

I am using the projection EPSG:3857 to plot out points on the map. Since the Earth is closer to the shape of an ellipsoid instead of a sphere, I am interested to find out what is the range of error if ...
0
votes
1answer
227 views

Setting projection to a geotiff file when it's shown as Unknown

I have a geotiff file that has no CRS in the metadata but I know that the CRS of the raster is WGS 84 UTM 22 N. How can I modify the geotiff file to have the CRS WGS 84 UTM 22 N in the metadata. ...
1
vote
1answer
715 views

OSM Map projection doesn't seem to change

I have the following OpenLayers map: Proj4js.defs["EPSG:31258"] = "+proj=tmerc +lat_0=0 +lon_0=13.33333333333333 +k=1 +x_0=450000 +y_0=-5000000 +ellps=bessel ...
1
vote
0answers
86 views

OpenLayers doesn't understand Mercator map measured in degrees?

I have access to a map server that takes a bounding box measured in degrees, and returns a map, projected in Web Mercator. I'm having trouble configuring OpenLayers to use a Mercator projection that ...
4
votes
2answers
1k views

Create custom projection using either QGIS (or ArcGIS)?

I have searched for an answer to this but don't see anything relating to what I am trying to do. What I have are a series of Geographic Coordinates, Latitude, Longitude, Ellipsoid heights. What I ...
6
votes
1answer
180 views

Is there a difference between projecting shapefiles then rasterizing & rasterizing shapefiles then projecting?

I currently have a project where I rasterize shapefiles into simple presence/absence (1 & 0) rasters and then add each one to a running total to create a total richness raster at the end. The ...
2
votes
2answers
650 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 ...
1
vote
0answers
212 views

Project tiles from custom imagery in transverse mercator with OpenLayers

I have the following parameters of a custom imagery and I need to set-up a layer in OpenLayers with which I would project the tiles properly from this imagery. TransverseMercator ellipsoidName=WGS84 ...
2
votes
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 ...
1
vote
0answers
274 views

A WMS layer fails to show at some scales

I am tring to overlay my WMS layer on Google but at a particular scale it doesn't show the data of my layer. What can be the problem? <html xmlns="http://www.w3.org/1999/xhtml"> <head ...
1
vote
0answers
294 views

ScaleLine shows NaN for LCC projection

I have used openlayers along with geoserver. My Map is having LCC projection by default, but SRS is EPSG:4042. The problem is that the scaleline shows NaN in meter as well as feet. How can I correct ...
2
votes
1answer
2k views

Mapping x, y pixel coordinates to latitude and longitudes on the WGS84 datum

Apologies in advance for the long question, I am fairly confused at this point and I figure if I show my thought process any flaws early on in the piece can be more easily pointed out. I have a grid ...
1
vote
1answer
210 views

Problems with matching layers with different projections

I have two layers with the following projections: Monte Mario IT1 UTM* Anyhow, I followed the instructions (open the project, set the projection, select on the fly projection, load the layers but no ...
0
votes
1answer
1k views

lonlat from geometry point gives strange result

I added a vector layer to my main map with the controls like the example from openlayers: http://openlayers.org/dev/examples/draw-feature.html Now when I want to get the resulting lonlat from the ...
3
votes
0answers
510 views

Get tile URL with projection different than 900913

I have the following code, which should display a slippy map showing tiles producted by me with mapnik: Proj4js.defs["EPSG:31258"] = "+proj=tmerc +lat_0=0 +lon_0=13.33333333333333 +k=1 +x_0=450000 ...
2
votes
2answers
509 views

GeoTools Oblique Mercator Example

I would like to use the Oblique Mercator projection in GeoTools. I'm currently using a WGS84 Mercator projection like this: final CoordinateReferenceSystem wgs84CoordSystem = CRS ...
3
votes
2answers
603 views

Looking for formula for the Robinson projection

I'm looking for a source that describes how the Robinson projection is calculated. I'm going to use this for converting long/lat into Robinson coordinates in both R and in javascript.
1
vote
1answer
831 views

When I import polygon kml layer, how do I change projection and offset to correct for GMT wrap?

I created a polygon in Google Earth and saved to kml. After importing as a vector layer, where the polygon crosses the prime meridian, the polygon wraps around the world. So far, I have figured out ...
1
vote
1answer
508 views

Geoserver and SRS

I have a very basic problem, and please bear with me since I'm new to GIS. I have geoserver installed in a Ubuntu Box and installed a few maps in shapefile. The maps were originally in ArcGIS format ...
8
votes
2answers
713 views

How to determine projection parameters when customizing a projection

I am trying to customize an Albers and a Hotine Oblique Mercator (HOM) projection to minimuze distortion in the region I am analyzing. The region extends from about 51 to 62 degrees latitude, covering ...
15
votes
2answers
3k views

Calculate distortion outside a UTM zone

One of my colleagues is working with data that is spread across two UTM zone. The majority of the data is in one zone, with a few outliers in another zone. He would like to know what the area ...
6
votes
1answer
1k views

Python script to convert Lat Long to ITM (Irish Transverse Mercator)

I am currently working on a python script that converts Lat Long (WGS84) to ITM. The formulas used are based on a paper published by OSGB (Appendix B): ...
1
vote
1answer
303 views

Project layer with custom projection

My ultimate goal is to know UTM and UTM Northing and Easting. The data can be anywhere in North america. I calculated UTM using arcpy tool (arcpy.CalculateUTMZone_cartography) and I tried to truncate ...
3
votes
1answer
672 views

Calculate bounding box + buffer for rendering a map tile with mapnik library

Mapnik library has a Projection object (I'm using Python bindings): spherical_mercator = '+proj=merc +a=6378137 +b=6378137 +lat_ts=0.0 +lon_0=0.0 +x_0=0.0 +y_0=0 +k=1.0 +units=m +nadgrids=@null ...
2
votes
1answer
203 views

domain for transverse mercator projection, using proj.4

I have to apologize for the naive question -- it's my first encounter with projections and this software package, and I intend to use it for a non-geographical application (hence I work on a unit ...
3
votes
2answers
4k views

Why does QGIS scalebar show a wrong scale?

I'm using QGIS 1.7.1 and have added a scalebar. The scalebar usually displays in degrees, unless I switch the map's projection to meters, in which case the units are display in cm. This is not ...
3
votes
3answers
2k 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 ...
3
votes
1answer
271 views

Is there no EPSG code to use for Behrmann equal-area projection in ogr2ogr?

I'm trying to use ogr2ogr to reproject some shapefiles. The projection I wish to use is Behrmann equal-area. I cannot find an EPSG code to use for the '-t_srs' part of the syntax. Is there any way ...
2
votes
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: ...