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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Clustering the WGS84 point features (projection transformation aspects)

My question is quite trivial and was discussed many times before (like here) but in our case it has the confounding extra requirements... The list of sparsely distributed 2d point features is stored ...
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27 views

Projecting Data with Transformations - Alignment Issue

Problem: I am having problems getting data to align properly with basemaps layers. The image below shows the difference between roads. The centerlines shapefile's coordinate system is ...
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358 views

How to overlay a flat image onto google maps with two points of reference?

The Android API allows for images to be superimposed onto a map. To do so, the developer specifies a set of lat/long coordinates for an "anchor point" within the image, the width (or height) of the ...
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74 views

Arcmap: transform an image from Web Mercator Projection to Simple Cylindrical (Plate Carree) projection

I have an image that is projected using the Web Mercator projection. Does anybody know how to transform (in Arcmap) this image from the Web Mercator projection to the Simple Cylindrical (Plate Carree) ...
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43 views

Vector seems to be only a pixel of a raster after reprojection

I have the South America hydro1k data for slopes and I am trying to extract the data using point sampling tool with a grid in Brazil's map. My problem is that, even though vector and raster seem to ...
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91 views

Google Map Projection Skew - Need correct Projection

I'm having a really difficult time resolving skewed grids when projecting onto Google maps using Alteryx outputs. Within the module, I'm taking GRD files and aggregating rows and columns to re-size ...
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43 views

Question about projected coordinate systems 30m DEM for Contiguous US

What is the best Projected Coordinate System (PCS) for the contiguous US (whole, not parts) if I want to maintain distance and area accuracy as much as possible across a nationwide DEM dataset? I'm ...
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68 views

Why can't I reproject from HARN State Plane Ft Intl to State Plane Ft?

I'm attempting to reproject a feature class that is: NAD_1983_HARN_StatePlane_Oregon_North_FIPS_3601_Feet_Intl to our standard, which is: NAD_1983_StatePlane_Oregon_North_FIPS_3601_Feet When I ...
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58 views

Geodjango transform introduces large errors

Apologies for the possibly naive question. I'm trying to understand how Geodjango (running on PostGIS) deals with coordinate transformations, and am experiencing some unusual behaviour. Let's say I ...
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153 views

MySQL+GDal+MapServer+OpenLayers WebMercator problem

I have a problem/question what is the most efficiant way to go from WGS84 (epsg:4326) to webmercator. Outline of the structure right now: MySQL Database: with point Latitude/Lontiude Data [~200 ...
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144 views

Conversion problem of projection of MODIS LAI from sinusoidal to geographic

I am trying to change MODIS data's (LAI) sinusoidal projection to geographic. Actually I did it. But when I reproject it by ERDAS, the output LAI raster moved about 10 km to west side of actual shape ...
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160 views

Creating custom projections with Proj4

I'm reading into how to customise projections with Proj4 - specifically to achieve tilted projections such as the example below (from vis4.net) The Proj4 literature is pretty heavy going and having ...
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138 views

Calculating closest distances in meters/kilometers given lat/long coordinates?

I am using ArcGIS 10.2 for Desktop. I have a shape file containing points worldwide with lat and long, and another world map polygon file whose Geographic Coordinate System is GCS_WGS_1984 and Datum ...
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39 views

Add a raster specifying the projection in pyqgis

I would like add an raster but I want to specify the projection. If I do : qgis.utils.iface.addRasterLayer(url,layerName) QGIS ask me to specify the projection. I want to this with python. How I ...
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136 views

Kartograph - “projection not named”

The Kartograph package looks very promising, so I have been trying play around with it. As it turns out, I have been able to get the most basic map to work (the "world.json" example), but I could not ...
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71 views

How can I obtain the unit of a projection SRID?

Given a projection SRID, is there a way I can obtain the coordinates unit string (meter, degree, ...) ? In PostGIS for example, it looks like it is present in the srtext column of spatial_ref_sys. ...
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246 views

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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125 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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423 views

Help me convert this US Lambert Conformal Conic Google Maps Projection to Australia

Following on from this question: Identify what projection this Australian map uses? <- this is the sort of map i want to load in I need help changing the bits necessary in this example of Lambert ...
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786 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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47 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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49 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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343 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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137 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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611 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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230 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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134 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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89 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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72 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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466 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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116 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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242 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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697 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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138 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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229 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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124 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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263 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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203 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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287 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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115 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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267 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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194 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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369 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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359 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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145 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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491 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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687 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 ...