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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Incorrect coordinates when reprojecting NAD27 to NAD83

I have some historic UTM coordinates as NAD27 (556787, 7169250) which I entered into a spreadsheet and have imported into QGIS. I assign them the projection Nad27 / UTM zone 12N (EPSG: 26712) I ...
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104 views

Am I correctly projecting a geometry using a WKID in ArcObjects?

I would like to take in any valid WKID for a spatial reference and then project a single geometry to it. The following code seems to be working, but (1.) can someone verify that this is the correct ...
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913 views

How do I change from lat/long to a metric coordinate system in GRASS?

Yes, it's yet another transformation question. I am working with ASTER DEM data, which is LatLong WGS84. I want to process the DEM map into an STL file for use in a CFD simulation. The script I am ...
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633 views

How to set Scale Factor for Lambert Conformal Conic (LCC) projection in ArcGIS Desktop?

The projection for my state according to my country's Mapping Agency is in a specific Lambert Conformal Conic (LCC) projection. They have given values for the following parameters: False Easting ...
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45 views

CRS centered on the 180 meridian?

The problem I'm dealing with is the old 180 meridian problem, except I'm not trying to plot or render shapes that cross it, I need to do intersections of lines that cross it. The only spherical ...
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47 views

Create oblique projection?

bit of an odd one which isn't necessarily package-specific. I'm trying to make a tshirt with a map section centred on the plane between San Francisco, USA, to Galway, Ireland. The Great Circle line ...
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283 views

Reprojecting GeoTIFFs to WGS84/UTM

I'm using libgeotiff and proj4 to read and (try to!) process GeoTIFFs. After reading the file, I want to get the corner coordinates in WGS84/UTM - but there are so many functions and parameters to try ...
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127 views

Trying to convert to EPSG:27700 (Ordnance Survey) projection, unable to do so

I'm trying to code an interface that allows a user to draw a vector shape on openstreetmap, which is then converted to a WKT string, processed by the server and sent of as a WFS query to emapsite ...
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564 views

Using gdal to convert from UTM to equidistant lat/lon

I am getting rather confused with converting a UTM gridded dataset into a equidistant/rectangular latlon gridded dataset. Can anybody help me? I have a UTM set with the following projection: ...
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55 views

how to get correct geo reference system for a VMap

I am new to GIS, trying to read the GeoRef System for VMap by using the following code: OGRSpatialReference *ref = layer->GetSpatialRef(); if( ref ) { QString georefSystem = ...
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198 views

Reprojecting raster data from a rotated pole grid

I have some raster data (ASCII grid files) that use a custom rotated-pole projection, that I'd like to reproject into something more useful, such as lon/lat WGS84. A description of the grid projection ...
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125 views

How to join edge of International Date Line in world file?

I am currently using world file (http://www.ngdc.noaa.gov/mgg/shorelines/gshhs.html) for international boundary information. Now I have difficulty with map projection that the map ends with ...
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85 views

How to import multiple shapefiles each with different source projections to postgis

I have a couple thousand .zip files each with a .shp, .dbf, .shx, and .prj inside them that I want to load into postgis. The problem is, they have many different source projections (each defined in ...
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70 views

Projection for Tracking a Vehicle

I'm looking for the best coordinate system projection to use for cartesian calculations while a vehicle is running from its starting location to about 100 miles from that spot. The offline format ...
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402 views

Lines as Great circles on a map

How can I get line features to appear as great circles on a map, instead of straight lines? Thanks,
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106 views

What is a radar projection?

Trying to overlay a radar image(radar projection) on a mercator projected map, but have no idea about what a radar projection is. So here are my quesions: What is a radar projection? What's its ...
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226 views

What is UTM Zone 0?

I am currently working with some roadway link data and it is being projected in UTM. After importing the shapefile into GRASS I can view the map and it looks correct but when I view the projection ...
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541 views

ArcPy 10.1 PointGeometry.projectAs()

I'm trying to reproject an X,Y passed in from an Add-in. So far this works fine: pointGeometry = arcpy.PointGeometry(arcpy.Point(x,y),srIn,False, False) projectedPoint = ...
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132 views

Converting altitude in feet to pixels on a mercator map image

I know the question might seem farfetched given that the map is 2d. But I essentially want to project items-aircraft-above the map and I would like their altitude to be vaguely 'realistic' in terms of ...
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219 views

How to overlay 3 different layers using ArcMap

I have to overlay 3 different layers called "Bacino Isonzo Perimetro", "Bacini Tributari Isonzo", and "Isonzo" in ArcMap. Layers'properties are shown below. BACINO ISONZO PERIMETRO Data Type: File ...
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117 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 ...
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241 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 ...
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85 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 ...
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186 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 ...
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268 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 ...
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1k 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 ...
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112 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 ...
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259 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 ...
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191 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 ...
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351 views

Conversion From Transverse Mercator To Longitude & Lattitude

I have to transform (7-parameters datum transformation) coordinates from northings & eastings to lattitude & longitude. Following are details of source coordinate system(i.e. northings & ...
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334 views

How do I use Proj4js or other technique to make custom map projections with google.maps.Projection?

I'm using Google's Projection class to try to convert my map projection from the default spherical mercator to something like Lambert Conformal Conic. I was previously adapting the code from this ...
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136 views

How to show an array of 2d points/polygons in Polymaps (Cartesian coordinate system)

I need to display these 2d points/polygons (Cartesian coordinate system) on Polymaps with GeoJson layer. I do not use the other layers. Do I need to convert xy coordinates to the lat lon? If so, how? ...
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454 views

Geoserver tiles mismatch

I tried to get WMS tiles from geoserver like /geoserver/gwc/service/tms/1.0.0/layername@EPSG%3A4326@png/15/19142/9530.png or with another projection ...
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637 views

mixing lon/lat and mercator layers in a MapServer .map file

I have a basic question about my MapServer .map file, which has two layers, each with a different coordinate system, longlat vs. mercator. See my .map file below. If I leave it as shown below, with ...
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389 views

Moving GPS Points with a VB script - Bearing works well but distance is wrong

I am using a script I found online created in 2003 by one of the commentators here. It is a great script and exactly what I have been looking for and I'm very glad to have found it. It simply takes ...
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15 views

Is there a formula for calculating 2D map distance from 3D information?

Using ThinkGeo, I have a Lat/Lon coordinate, and a distance of .1 miles. The .1 miles represents the radius of a circle and I'm trying to draw this radius around the lat/lon coordinate. The map units ...
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19 views

Projection of COSMO-EU?

I have data points of COSMO-EU data stored in WGS84 coordinates. Now I try to transform them into coordinate system where the points becomming arranged to a regular grid. Does anybody knows the Proj4- ...
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76 views

How to prevent cross-world lines in ggplot world map?

I'm having issues displaying 'great circles' paths and polygons in ggmap, an extension of ggplot2. Please enter the following code to replicate my issues: ...
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47 views

GeoTiff using GDAL

How can I project a tiff using the position of the four corners where the picture have to be placed ? The tiff file has no georeference or projection information I have got a grid with values of ...
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24 views

reprojecting (unprojecting) in MrSID decode (SDK)

I am using the C++ SDK (version MrSID_DSDK-9.1.0.4045-win32-vc9). I'm trying to read in arbitrary .sid files and extract rectangular sections of them that can be displayed on top of a "web mercator" ...
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82 views

OpenStreetMap with OL3 and EPSG:3301 projection

Trying to add OSM layer to my map, as Tile layer or as WMS layer, but for Tile layer it is appearing in different projection, and for WMS layer there are error Resource interpreted as Image but ...
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29 views

Pros and Cons of a latitude adjustment grid vs other methods of area calculations

When working with high resolution global raster data in WGS 1984 I often need to calculate areas. Now the traditional way for me to achieve this has been to reproject the data to an equal area ...
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30 views

How can one use Google Maps API to mimic QGIS projection/CRS

I used QGIS to find the extents of a list of features. However, the resulting data auto-generates the CRS and changes it from WSG84 to a custom one. Is there a way to use the autogenerated CRS in ...
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35 views

Precision loss when transforming coordinates systems in GDAL (vector layers)

Anybody knows the order of magnitude of the error introduced when transforming coordinates using GDAL? More specifically, I would like to know if significant error is introduced when the ...
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211 views

Transforming between epsg:3857 and Google Maps Tile coordinates

Hio, I used to use a simple python project (https://github.com/hrldcpr/mercator.py) to convert between wgs84 and google maps tile coordinates. This project doesn't have a license, and looks like it ...
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24 views

How to get ASTER level 1B data to overlay correctly on google earth/ bing maps/ arcmap imagery basemap

I have recently purchased Two granules of ASTER 1B data from ERSDAC. Upon importing this data into arcmap 10.2, the layers representing each band were specified as being projected in: ...
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65 views

Striping Artifact in Aster DEM Mosaic

I'm working with SRTM and ASTER data for a university project. My goal is to delineate watersheds and evaluation of these with ArcGis 10 and ArcHydro. But a striping error occurs with the flow ...
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67 views

How to generate map tiles with TileStache and a custom projection

I would like to generate my own map tiles using TileStache and a custom projection. I have been struggling with this for quite some time and am hoping I can get some advice to get the tiles to ...
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64 views

Understanding X Y coordinates: geocode before or after projecting? What determines how many decimal places?

I am trying to figure out how different my groups' past Network Analyst analyses have been because they were using a geographic instead of projected coordinate system. But I'm getting hung up on the X ...
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55 views

Is it possible to rotate the geographic projection in QGIS?

I'm trying to create a Qgis plugin that can rotate a raster layer in the canvas so that the north is pointing at another direction. Unlike the thread below, I'm open to defining a custom projection. ...