A map projection is any method of representing the surface of a sphere or other three-dimensional body on a plane
6
votes
1answer
600 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
131 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 ...
0
votes
0answers
26 views
how can I calculate in different UTM Zone? [duplicate]
Possible Duplicate:
How do you best deal with data that spreads across UTM Zones?
I get two points in Lon/Lat in WGS84, but they are not in the same UTM zone, eg, p1(102.977319,30.957558) ...
7
votes
2answers
247 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
122 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 ...
0
votes
0answers
67 views
Proj4js accuracy compared to Proj4
Is there any lost of accuracy in reprojecting using Proj4js in the browser (compared to using server side Proj4 in Mapserver ) ?
11
votes
2answers
778 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 ...
8
votes
1answer
206 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 ...
8
votes
2answers
204 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
145 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
305 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 ...
1
vote
2answers
174 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
...
2
votes
3answers
839 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:
...
1
vote
0answers
166 views
Imported netcdf file doesn't project correctly - help!
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
470 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: ...
2
votes
1answer
108 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
vote
0answers
382 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
344 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 ...
2
votes
0answers
85 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
335 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
67 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.
...
4
votes
2answers
2k 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
161 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
2answers
286 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
93 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 ...
3
votes
3answers
486 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
217 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 ...
1
vote
1answer
170 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 ...
0
votes
0answers
66 views
How can I convert a Winkel Tripel map to a Mercator map?
I have a map of the world (a PNG file) which uses Winkel Tripel. I'd like to convert it to Mercator. I would just use pyproj, but it lacks an inverse "wintri" projection.
4
votes
1answer
125 views
What is the most appropriate Projection for the Gulf coast region?
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.
...
0
votes
0answers
294 views
How to convert map coordinates to lat long values in Lambert projection with WGS84 datum using Java?
I want to convert map coordinates values to latitude,longitude values. The image is in Lambert Conformal Conic projection with WGS84 datum, WGS84 ellipsoid. Please suggest to me the formulas involved. ...
14
votes
1answer
763 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
188 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 ...
5
votes
1answer
116 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
438 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
239 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
113 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
113 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. ...
3
votes
2answers
189 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",
...
3
votes
1answer
147 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 ...
0
votes
1answer
316 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:
...
2
votes
0answers
33 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
235 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 ...
0
votes
1answer
941 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
136 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 ...
3
votes
1answer
422 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
113 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
...
0
votes
2answers
133 views
How do you pass parameters for Proj4js implementation with OpenLayers
I am using Proj4js along with OpenLayers for the transformation of x,y (projection type is Transverse Mercator) to long, lat.
While executing "inverse()" method what I noticed that in tmerc.js some ...
2
votes
1answer
290 views
How to transpose the lat/lon coordinates of a shapefile?
I need X to be Y and Y to be X (switching lat/long) within the polygon shapefile. If it were a point shapefile I know I could simply reverse the lat/long or x/y parameter and import from a table. I'm ...
1
vote
1answer
100 views
Tool For Generating Formula for Projection
I am using Proj4Js for northing,easting to lat,long transformation.
My Datum is "AGD84" and projection is "Transverse Mercator".
While doing so I found that if I don't specify "+proj" parameter in ...
