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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Are there tools in ArcGIS for drawing compass bearings, and which projection should be used to create a map showing them?

I have a requirement to create a map (or multiple maps) showing four different locations with a bearing compass drawn around each one, oriented towards Grid North. I was told that each of the ...
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130 views

Should I Reproject Data Which Has Been Captured Incorrectly?

I'm working on a project for a client which is migrating data from an Oracle database to an ESRI Geodatabase. When data for this project was initially captured over 15 years ago, the coordinate ...
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Projecting selection from large data set using ArcPy?

I have a large data set X(x1-xn) from which I must select consecutively the attributes A(a1-an) from X.fieldsSRC or X.fieldDST and project the selections. I have a functioning arcpy script that does ...
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Openlayers and Geoserver: OSM/Google Maps and WMS Overlay

I am experiencing projection problems with the following set up: GeoServer with ESPG:4326 based shapefiles (*.shp) OpenJump to edit my shapefiles Openlayers with EPSG:900913 base layers GeoServer ...
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1answer
507 views

How do I change an existing srs in QGis?

I am showing postgis data with srid 28992 (Amersfoort / RD New). But when I plot the geospatial data on a map (with openlayers plugin), the data is shown a hunderd meters off because the datum shift ...
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211 views

Which training courses in Geodetics can you recommend?

Can anyone recommend any training courses in geodesy which would cover the following objectives: Case studies on coordinate issues Overview of geodetic datums, coordinate reference systems and ...
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309 views

What's a robust strategy for displaying 3D map data for navigation?

3D map data, specifically the kind you see on GPS units, or more recently on smart phones, almost always features a 'HUD' like view, which I'm trying to implement in an application of mine. I have ...
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How to convert coordinates from Gauss-Krueger to Longitude/Latitude?

I'm a newbie in the GIS world so please advise me :) In my .NET/C# project I need to show some shapes/points on the Bing Map. The problem is I have the Gauss-Krueger coordinates and need to convert ...
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What is the projection of WGS84 in GIS software?

WGS84 is a reference ellipsoid that determines coordinates of every point on Earth using latitude, longitude and height about the its surface. This ellipsoid is often used as a base to make maps. ...
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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 ...
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Automate Projection of multiple shp files using ArcPy

I have been trying to create a Python script that will convert all shape files within a folder from GCS WGS 84 to Web Mercator. Below is the code I have so far but what I'm struggling with is how to ...
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How do I get the distance meter value between two geometries in PostGIS?

I have a simple question about calculating distances in PostGIS. I would like to get the distance between two geometries. I am using this sid : 4269 in meters what i am doing now is this : ...
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462 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 ...
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525 views

How to efficiently project datasets of varying coordinate systems into one coordinate system?

I am working on streamlining data processing at my organization. Currently we are using various large-scale Models that we will gradually bring into Python. The gist of our data processing is as ...
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377 views

Reprojecting LiDAR data with libLAS

I have a lidar file (file.las) with the following spatial reference: Spatial Reference: PROJCS["NAD83 / UTM zone 11N", GEOGCS["NAD83", DATUM["North_American_Datum_1983", ...
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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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171 views

Good projection for covering most of the world

I'm writing an application for building navigation routes thru the city streets, and not quite sure what projection would be best. I tried EPSG:3587, however, the tools I'm using - GeoTools and ...
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Mercator projection: problem with latitude formula

I'm trying to get the position of a coordinate on this map (source Wikipedia): If I'm correct than the formula for the position of the latitude would be: R * ln(tan(pi/4 + latitude / 2)) But ...
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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", ...
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331 views

Which projection casts rays from a point on the surface of the globe to a cylinder?

What is the name of a map projection that casts rays from a point on the surface of the globe to a cylinder? Some people who make sundials put a map of Earth on the sundial. I want to use the "right" ...
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358 views

Does the Chamberlin trimetric projection map (some) great circles to straight lines?

I know that, in general, the Chamberlin trimetric projection maps most great circles on the sphere to some sort of non-straight curve on the flat map. But what about the 3 special great circles ...
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56 views

Shapefile projections not matching up in QGIS?

To start off with, I'm very new to QGIS. I'm attempting to place a shapefile with locations for 3 substations on a map of Peniche, Portugal. The locations for the substations are given in latitude and ...
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849 views

Why is tiff different in epsg 3857 and epsg 900913 in gdal

When I transform tiff from 4326 to 3857 and from 4326 to 900913 in gdal, I get different result(when display in Qgis) eventhough these two projections(3857 and 900913) should be the same. What is ...
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Manipulating Azimuthal Equidistant Projections in QGIS

I have a shapefile of world countries that is projected as Azimuthal Equidistant with Chicago, USA as the center. I would like to change the projection such that Edinburgh, UK is the center. One would ...
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743 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 ...
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113 views

Are perpendicular lines still perpendicular after converting from UTM zone 15 to 16 (or between two neighboring zones)?

I want to convert a square polygon that is close to the edge of UTM zones 15N and 16N. The polygon's coordinates are in UTM 16N, but it is spatially positioned in the UTM15 area. My question is that ...
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54 views

Pacific-wide Projection for distance?

I have a data set of ~3500 points located across the Pacific Ocean, and am looking to measure the distance from each point to it's nearest coastline to identify the "host" country. I had originally ...
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208 views

Coordinate/projection system issue in ArcGis 10.3

I am new in this community and I am also a new user of ArcMap. I am facing a problem, my shapefiles are in a GCS WGS 1984 and I have to add a new shape file that is in a projected coordinate system ...
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344 views

Having trouble finding out what coordinate system a map is using, and how to convert it

I'm using Small Area shapefiles in Ireland from the Central Statistics Office (CSO) website. The link to these is here http://census.cso.ie/censusasp/saps/boundaries/ED_SA%20Disclaimer1.htm (Look for ...
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Coordinate system and projection for georeferencing Google Maps image in ArcGIS Desktop?

I have saved Google Maps image (not Google Earth) of area at latlon(17.692437,83.218689) by some method in jpeg format. It is an exact snapshot of the Google Maps. Now I need to geo-reference it to ...
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How to convert NAD 27 to WebMercator in using the ESRI Silverlight API? (C#)

I am working with the ESRI Silverlight API. I found THIS post in the ESRI forums and THIS OTHER which show how to convert between WGS84 geographic coordinates and WebMercator coordinates. I want to do ...
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801 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 ...
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3answers
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Convert Nasa's Blue Marble into a cubic projection

I'm looking for a free tool to convert the cylindrical projection map of the Earth's surface that you can get from Nasa (under the Blue Marble project): ...
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1answer
662 views

How can I specify a PROJ.4 projection with the north pointing *down*?

I would like to create a world map "upside down", with the south on top (in Mapnik). Can I take an existing projection string, e.g. Robinson projection +proj=robin +lon_0=0 +x_0=0 +y_0=0 ...
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1answer
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Projected maps should but do not overlap in ArcMap? [duplicate]

I am very new to ArcGIS and trying to build a series of layers of data in ArcGIS 9.3.1 for a river catchment in Leicestershire, using data from several sources. All data covers at least the area of ...
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1answer
275 views

Projecting a world map on 6 segments to print on ball

Working with QGis and data from Natural Earth I would like to prepare a world map (1:50 000) for a globe that can be printed in 6 segments, which glued together build a ‘sphere’ (ball) according to ...
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69 views

Is there a difference in results between Simplifying a geometry by different projections?

We have geometries in a PostGIS database projected in srid 4326. We need to have these geometries simplified with ST_SimplifyPreserveTopology. My question is whether this geometry needs to be ...
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980 views

How to manually add spatial reference information for FEWS rainfall data in ArcMap?

I am trying to match rainfall data from USGS/FEWS to coordinate locations of survey households in Uganda, so I will need to be able to project the rainfall data. So far, I downloaded the dekadal RFE ...
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1answer
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Openlayers 3 WMS Projection

I am working with both EPSG:4326 and EPSG:4230 in OpenLayers 3 and I am using my WMS service which only supports EPSG:4326 maps. What I need to do is show a map in EPSG:4326 and transform it to ...
5
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2answers
564 views

Why is the Google Maps circle shape not matching to the distance calculated with PostgreSQL?

I am running a PostgreSQL 9.1 Database with PostGIS 1.5 extension. Several coordinates are stored in there with type GEOMETRY (SRID 4326). I'm building a web-application with Google Maps Javascript ...
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1answer
4k views

Converting Lambert Conformal Conic to WGS84 using Proj.4

I am attempting to transform data from Lambert Conformal Conic lat/long and I am having some issues with the results. The shapefile I am attemtping to transform can be found here: ...
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3answers
974 views

Plot a EPSG:4326 KML File using Google Maps V3

I have a KML file that uses EPSG:4326. Is there any way to plot this onto a Google Map (v3) which uses Mercator? Here is the page I am working on The district data comes from one source and is ...
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2answers
94 views

Why am I getting two different outputs from Python and C++ using GDAL?

I am trying to gather information from a *.tif file using the GDAL libraries. When I open the *.tif file using both the Python API, and C++ API, I encouter two completely different answers. Here are ...
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183 views

Azimuthal Equidistant - 40,000 Km range

I've been looking at making an azimuthal equidistant map. There are several web sites that offer to make one, based on my location, but they all have the same problem. They assume my antenna rotates ...
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164 views

What projection is this and how to use it in a GIS?

I have a request to do a map in non-standard projection: (source: http://www4.agr.gc.ca/AAFC-AAC/display-afficher.do?id=1263246127905&lang=eng) I couldn't manage to find it my materials. As well ...
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How to display KML image overlays in OpenLayers?

I am working on displaying Ground Overlays on OpenLayers by parsing KML manually. To do so, I was trying to add an image on top of Google Map by looking at GroundOverlay section from ...
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1answer
301 views

Mapserver tiles - trouble with projection

I'm trying to render tiles with shp2img tool from Mapserver suite and my tiles aren't matching. Tiles are numbered like in openstreetmaps.org. This is an attempt to draw tile (level 1, x=1, y=0) which ...
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1answer
762 views

What is north-up projection?

How do I know what projection to use for north-up or 0 rotation? I have a gtiff (ND83-nf) that gives me the error when importing to Grass. Should I re-project or recreate the image with the rotation ...
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773 views

Why are the coordinates transformed with proj.4 off compared to http://valdemar.kms.dk/trf/?

I am trying to transform from epsg:4326 (wgs84) to epsg:25832 (utm ETRS89) using Proj.4. I am comparing the results with results from http://valdemar.kms.dk/trf/ . it seems like the results ...
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How to manually change from GPS (WGS84) to web based maps projection systems?

I have collected location point data and wish to display this on a web based map. It was collected using a Garmin Etrex GPS using the WGS84 datum. I wish to display the points using Ushahidi and have ...