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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4
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2answers
818 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.
8
votes
5answers
6k views

Calculate distance in km to nearest points (given in lat/long) using ArcGIS DEsktop and/or R?

I have two point datasets in ArcGIS, both of which are given in WGS84 lat/lon co-ordinates and the points are spread across the whole world. I would like to find the nearest point in Dataset A to each ...
1
vote
1answer
1k 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 +towgs84=577.326,90.129,463.919,5.137,1....
5
votes
0answers
794 views

Evaluating map projection scale error

This is related to a previous question I posted. I am trying to quantitatively evaluate scale distortion associated with choosing different projection center, center azimuth, and scale factor values ...
1
vote
1answer
645 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 ....
3
votes
3answers
2k views

What is a good projection for the whole of China (with units in meters)?

I get some GPS results which lay in China with WGS84 coordinate system, and I need to choose a projection to reproject for. First I chooses the UTM projection, but I find the results lay in ...
1
vote
1answer
396 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 ...
6
votes
1answer
2k 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): http://www.leica-geosystems.co.uk/downloads123/...
1
vote
1answer
356 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 ...
9
votes
2answers
1k 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 ...
2
votes
1answer
226 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 ...
20
votes
2answers
4k 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 ...
9
votes
1answer
800 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 ...
10
votes
2answers
721 views

how to produce a Peirce quincuncial map?

As far as I know neither PROJ4 nor ESRI tools can apply the Peirce quincuncial projection. Does anybody know what libraries/softwares can manage it?
3
votes
1answer
349 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 ...
3
votes
1answer
838 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
2answers
680 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
3answers
5k 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: http://www.nyc....
1
vote
1answer
753 views

Projecting Imported NetCDF file correctly?

I have 360 NetCDF files (.nc) that I need to import into ArcGIS. They hold monthly historical climate data in the U.S. When I tried to import one, using the Make NETCDF Raster Layer tool, the ...
2
votes
1answer
901 views

Converting 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: 0....
2
votes
1answer
366 views

Mercator Didn't work on Geoserver

Got some problem with Mercator in Geoserver, I tried to display Flight Information Region that has been stored in my Postgre. The result is more likely drawing using Cartesian projection: I tried ...
1
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0answers
2k views

How to project geographic coordinates (lat/long) to a cartesian system (albers equal-area)?

I am using this matlab package http://www2.ocgy.ubc.ca/~rich/map.html#examples to project the latitudes,longitudes of my data to a specific projection. For this particular case I am using albers ...
2
votes
1answer
2k 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 ...
3
votes
1answer
399 views

1944 Cyprus Grid coordinate data projection problem in MapInfo

I have coordinate data from the 1944 British Army General Staff, Geographical Section (GSGS) Cyprus map which was cast on the Cassini projection, but was referenced to the Clarke 1880 ellipsoid where ...
5
votes
1answer
754 views

Custom Geographic Transformation on QGIS

Is there a way to create a custom geographic transformation with specifics parameters in QGIS like in ArcGIS? Okay, I want to tranform SAD69 system into WGS84. Well, I'm in doubt because in ArcGIS ...
2
votes
1answer
102 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. ...
5
votes
2answers
10k views

Arcmap 10 feature with undefined coordinate system projects incorrectly when projecton is defined

I'm fairly new to GIS, and am slowly feeling my way through ArcMap 10. I have run across a problem defining the Geographic Coordinate System and projection for a feature (the feature currently has an ...
6
votes
1answer
751 views

Create Mercator map with arbitrary center/orientation?

I want to see a Mercator map where I choose what latitude/longitude is in the center and what direction is "north". In some sense, a Mercator map of a rigid rotation of the globe. Does such a ...
1
vote
3answers
989 views

PRJ file for Stereo70 S-42 projection?

I receive lots of Romanian maps with the projection STEREO70 with Datum "S-42 for ROMANIA". I have only found the "Stereo 1970.prj" by ESRI, and when I open the maps with my GIS software the ...
1
vote
0answers
116 views

How to compute a map-to-screen transformation?

Every projection calculation I have come across dealing with the Lambert Conic projection converts the given Lat & Long to meters. So now the magical question: how on earth do you take the meters ...
7
votes
3answers
2k views

Convert an arbitrary meta-data-free map image into QGIS project

My background: experienced programmer, amateur historian, complete beginner to GIS (so I'm using QGIS). I did learn to use the QGIS georeferencer tool though. The input: suppose I have an image like ...
4
votes
2answers
743 views

Why isn't valid geometry not valid in NetTopologySuite when close to poles?

I have a Polygon which crosses the south pole: Polygon in WKT: POLYGON((5.86826073458095 75.6638564054071,-16.5436836399021 63.2220742891438,-19.3664667294083 59.846221066959,-21.7009816876343 56....
1
vote
1answer
272 views

QGIS Projections

I am new to the GIS world and have faired pretty well with ArcGIS 9.3, learned and still learning on the job. I would like to get a better handle on QGIS though. I linked the files from my dropbox. I ...
4
votes
1answer
232 views

Choosing Projection for Gulf coast region of USA?

What are the most appropriate datum and projection I could use for the Gulf coast region - spanning Louisiana, Mississippi, Alabama, and Florida? I have to analyze block group data along the coast.
25
votes
4answers
5k views

How does one calculate distortion on Equirectangular Projection?

I am trying to calculate distortion so I can distort overlaying text and forms to precisely match an image of an equirectangular projection. So, how does one calculate the distortion at a given ...
1
vote
0answers
299 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 id="...
8
votes
2answers
1k views

Projections appropriate for global analysis that preserve area and that preserve distance (but not necessarily in the same projection)

I am looking for a projection (or a set of projections) that decently preserve distances so that I can buffer every country in the world and have a similar level of minimal distortion for each. I ...
4
votes
1answer
1k views

How to use DotSpatial to project/reproject shapefiles on the fly

I would like to use DotSpatial to reproject shapefiles on the fly before loading them to GeoServer. I've been looking for tutorials on how to get started with this in vain. Any pointers on where I can ...
2
votes
1answer
486 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 ...
1
vote
1answer
239 views

Looking for CRS for NAD 83 UTM Zone 30N

I'm curious as to why the UTM zones are incomplete for NAD 83 in QGIS? I have a WGS84 shapefile that I would like to project to NAD83 UTM Zone 30N but can't find it in the QGIS CRS list. I see how ...
2
votes
3answers
622 views

coordinate definitions from nyc.gov open data SpatialLocation field

The NYC Open Data website has a dataset of street events. The last column is called SpatialLocation, and is defined as a text field. An example is below. It is clearly two points on a physical map. ...
5
votes
3answers
2k views

Is NAD 83 the same as EPSG:4326?

I'm getting mixed messages about these projections. For example -Is this projection below, NAD 83, 4326? GEOGCS["GCS_North_American_1983",DATUM["D_North_American_1983", SPHEROID["GRS_1980",6378137.0,...
3
votes
1answer
317 views

2 Shapefile vectors will not plot properly in same space

There are slight differences in 2 shapefiles projection information. I have activated on-the-fly, but they do not plot in the same space. I tried to save as new shapefiles with the same CRS, but ...
1
vote
1answer
515 views

Reprojecting non 4326 WMS image to spherical mercator

In OpenLayers, I'm trying to display a WMS overlay (EPSG:4269) from a server I don't have control over to a spherical mercator projection. Is there an equivalent to this: http://blog.sumbera.com/2010/...
2
votes
0answers
36 views

Why did my shapefile distance get smaller after changing the projection? [duplicate]

Possible Duplicate: Layers having the same coordinate system should overlap, but they don't. What's wrong? I'm working with a shapefile that has a geographic coordinate system and I ...
5
votes
2answers
465 views

Mass-update the projection in compressed GeoTIFF files

I have a huge set of compressed GeoTIFF files. Someone forgot to set the projection while creating the GeoTIFF files and I would like to add it now. If I use gdalwarp -t_srs source.tif target....
0
votes
1answer
2k views

Conversion from N,E to Lat/Long And Lat/Long to N,E will always be same? [closed]

I have an excel tool for the conversion of following lat/long: Lat: 23° 11’ 24.67503’’ S Long: 118° 46’ 6.15742’’ E , which gives me following N,E: Northing: 7,434,317.43 Easting: 680,991.69 But I ...
1
vote
0answers
216 views

On the usage of Proj4Js->tmerc.js

I am using "proj4js & open layers" for my mapping. I got projection & datum (which is based on "Transverse Mercator") of a local plane and this plane is part of a grid which returns ...
5
votes
1answer
810 views

Openlayers and Geoserver fail to reproject while editing Vector with WFS-T

I can't get the Openlayers and Geoserver work with WFS-T editing a vector layer. I have a layer of points where the Native SRS is EPSG:32639. After trying a lot of combinations, I ended up with two ...
2
votes
1answer
269 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 PROJCS["...