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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242 views

How to get projected centroids in QGIS?

I am trying to get a centroid for several polygons on a global scale, in a way that it would correctly represent the common centre of all the polygons, taking Earth's curvature into account. The ...
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149 views

How to fix Raster Dataset with numbers in Extent that look like latitude/longuitude but say metres?

In ArcGIS for Desktop 10.1, the Spatial Reference of my Raster Dataset reports that its units are metres (well meters) but the values look like decimal degrees e.g. -33 degrees is highly plausible but ...
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232 views

is it possible to project a shapefile to a raster's custom projection with command line gdal/ogr?

I have a raster with a user defined sinusoidal projection and a shapefile in lat/lng coordinates (I believe this is called 'unprojected'?). I'd like to use ogr/gdal's command line utilities to ...
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1k views

Changing the CRS of a shapefile

Im trying to convert shapefile from one CRS to another in QGIS. On the layer menu, I right click on the shapefile, save it as with other name and there I change the CRS to the desired one (WGS 84). ...
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176 views

Selecting features to project to different coordinate system?

I've got data from all over Europe in one feature class projected in Web Mercator Auxiliary Sphere. Due to the fact, that length and area values are not usable I'm now working on a python script (...
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2k 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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759 views

Projection of Shapefiles for Spain (INE)

I downloaded the official shapefiles for the municipalities of Spain from INE here. It has a lot of shapefiles, but I found out that the right one for what I need is esp_muni_0109.shp. I would like ...
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225 views

Compute global DEM topographic indices and compromise projections

I would like to compute global topographic indices based on SRTM elevation data. These indices are computed along river/channel networks extracted from a DEM and are a functions of both local slope ...
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627 views

Which Geographic Transformation to use for WGS_84 to D_Sphere?

I have a shapefile for world countries and I want to reproject it from GCS_WGS_1984 to Sphere_Eckert IV. However, it asks for Geographic Transformation; it says this is optional but it is required in ...
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2k views

Export to new projection in QGIS 1.8

I would like to use QGIS to convert a CSV file from UTM to lat/long. I imported the CSV file with the "Add Delimited Text Layer" plugin. This works fine, the data looks like it is projected properly ...
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829 views

Area calculation: Albers Equal Area vs Pseudo Mercator

I have a question concerning area calculations in South-East Asia for West-East range that goes from India to Eastern Malaysia and a North-South range from Northern India to Indonesia (xMin,yMin 74....
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767 views

High Resolution Sinusoidal Interrupted Projection of the Earth

My grandfather built a rather large globe 10 years ago and never got to complete it (he started drawing about a fifth of it by hand and just gave up after that). I have been looking for a sinusoidal ...
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785 views

Overlaying layers with different projections on Android

Hello, I'm trying to show a map on Android. I'm using two map providers and am having trouble when converting geo point(lat/lon) to point in my viewport(x/y in pixels). 1) the first map provider used ...
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738 views

How to generate a grid of horizontal equal-area rectangles in a Mercator projection?

I'm new to GIS so pardon my ignorance and bear with me. I'm generating a grid relative to a LonLat point. To make the cells all equal area, I'm creating it in 2163 projection. The problem is that when ...
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1k views

Setting the map projection in the flex API to an overlay layer

I'd like to use a basemap containing world map data as a backdrop to some point and outline data that I'm hosting in ArcGIS server in the ESRI Flex API, but I would like the map control to share a ...
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1k views

Conversion of any projection to latlong using proj4 string

I am using a tool which uses proj4 lib to project maps. I have a set of xy coordinates to be converted to latlongs with that tool. as I have the source projection string say +proj=aea +datum=NAD83 +...
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22 views

Strange Custom Projection can't be transformed

I've got a a database of feature classes that were somehow transformed into a custom projection that I don't understand, and there does not seem to be a way to get back out of. The projection data ...
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51 views

Projection issue with WMTS in QGIS?

I'm trying to connect to this WMTS in QGIS, but I'm having issues that I think are projection related. I use the Add WMS/WMTS dialog and enter this url: http://www.vernoncounty.org/arcgis/rest/...
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26 views

Given WGS84 bounding box, is there service that returns most accurate projection to use?

I'd like to find a service to convert lat/lon in WGS84 to an arbitrary coordinate system in metric that will be the most accurate for my bounding box. Does something like this exist? For instance, ...
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75 views

Way to Shrink Alaska and Hawaii for “Stereotypical View”

Is there anyway to shrink Alaska and Hawaii to create a map that looks like the stereotypical map with AK in the corner, etc.? I thought about trying to isolate AK and HI in their own layers and then ...
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55 views

Alaska Series E projection in ArcGIS for Desktop?

I am trying to digitize a scanned map that appears to be in the Alaska Series E projection. I have also seen this referred to as Modified Transverse Mercator. While this projection is listed as ...
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112 views

What projection to use to get a game map into QGIS?

I have built and maintain a SWTOR game map atlas. At the moment, it's all static jpg maps, but I would like to get the info into an actual GIS software to get more functionality and make my website ...
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243 views

Defining projection using readOGR if the shapefile doesn't have it?

I think that by using readOGR to import a shapefile renders worthless to put proj4string to the script since if any coords are available in the shapefile, it will be transported through the readOGR. ...
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229 views

How to plot a full hemispheric orthographic projection in R

I want to make a plot like that using R: All I want is the country borders as seen from outer space, no fancy colors needed. It seems I need to use the spTransform function, but it gives me a "non ...
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248 views

Reprojecting MODIS Ice Sea Temperature products with gdalwarp

I have problems projecting MODIS Ice Sea Temperature (IST) products to EPSG:3031 (Antartic Polar Stereographic) using gdalwarp. The product I'm working with is MOD29E1D, documented here, p33: The ...
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543 views

How to use PROJ4 to reproject a file

Unfortunately, GDAL does not support a particular projection I am trying to achieve (the ob_tran rotated pole projection), so I am trying to use PROJ4 to convert a geotiff file to the projection I ...
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1k views

QGIS DXF file projection match

I need to use this file on a map but I am not able to match the projection with the others I have, primarily data downloaded from OSM (city of Boston). I read many articles, I have repeatedly tried to ...
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398 views

in python, srs.ExportToProj4() returns an empty string, why?

I have a shapefile with the following .prj file: PROJCS["NAD_1927_Albers",GEOGCS["GCS_North_American_1927",DATUM["D_North_American_1927",SPHEROID["Clarke_1866",6378206.4,294.9786982]],PRIMEM["...
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227 views

What are the set of projections that can be accurately georeferenced using polynomial 2?

Background I'm starting with a map from the internet (Encyclopedia Britannica) and georeferencing it using QGIS 2.0.1, I get really accurate georeference solution using polynomial 2 transformation: ...
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411 views

Calculate distance in QGIS, wrong geographic projection?

I'm trying to do the following: I have 2 shapefiles, one containing all the public schools in NY, another one containing the hotspots in NY (both in points form). Now what I'm trying to do is ...
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50 views

Does IDistanceOP.EucDistanceFull require a projected coordinate system?

I have designed an implementation of ArcObjects' IDistanceOP.EucDistanceFull. It takes its input as a feature class and converts it to a GeoDataset with which EucDistanceFull can work with. It works ...
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8k views

What are the units of the calculated area from a raster in decimal degree

I'm trying to calculate area for a raster file which contains 2 layers (0 for unsuitable habitat and 1 for suitable). It's been calculated successfully but I don't know what is the unit of the ...
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978 views

Finding projection of point to line?

I have a segment defined by 2 LatLon points(A and B) and a third LatLon point (C). I need an alghorithm, formulae, or some code to find the projection point of C on the segment AB (call this point D) ...
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778 views

How do I reproject one raster to match another's in GRASS

I have two raster layers, A and B, which have information about the same location but have different projections and datums. How can I reproject layer A to match the projection and datum of layer B? ...
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172 views

CRS Austrian Lambert/WGS84

I am totally new to Qgis (or GIS in total): My problem is to get two layers in same CRS to do an intersection and further analysis described in the blog of underdark (Groupstat tutorial). My is the ...
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1answer
482 views

USGS GeoTiff extent via GDAL

I have 2006 land cover GeoTiff from the USGS site (for a county in VA, USA). The projection is Albers Conical Equal Area Units. The download came with an HTML metadata file that tells me the geo ...
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444 views

Question Regarding Interpretation of Openlayers BBOX in 4326 Projection

I have a BBOX strategy in my Vector layer, which is sending HTTP GET Requests to my server in order to get the features I wish to display. The projection of the layer is EPSG:4326, so it is my ...
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240 views

Converting lat lon into co-ordinates (in ft of m)

I have a set of latitude and longitude of a series of points which specific the trajectory of a vehicle. If I consider the first point as the origin (0,0), is it possible to convert the trajectory ...
3
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402 views

Problem in displaying a GeoTiff image in JMapFrame

I'm trying to display a GeoTiff image with no projection but where the geographical extent (bounding box) is known: reader= format.getReader(new File(sImageName)); GridCoverage2D gridCoverage= reader....
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840 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 +...
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1answer
401 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 ...
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1answer
33 views

Configuring Project CRS to reflect degree coordinates

seems like this is a common problem, but posts with similiar questions did not solve my problem. I have close to zero GIS background so apologies for my ignorance. My goal is to extract only a ...
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24 views

How to do a custom, ad hoc, affine transformation?

I have a data set of unknown origin (probably CAD) and I have determined that the correct transformation for this data into the projection that I want is as follows: (4x + 2205432), (30y + 1254781) ...
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36 views

Rectangle shapefiles with the same extents does not align perfectly after projection

I have a rectangle shapefile built with UTM19 coordinates using a python script, and then projected to NAD83_CSRS (EPSG:4617). I have a second rectangle shapefile built with the same method (python ...
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75 views

Visualizing netCDF file with unknown projection

I'm having a tough time visualizing a netCDF file with poor metadata in ArcMap, which is probably not a surprise. I know the file to contain ozone concentrations over the United States. If I try to ...
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76 views

Coordinate points not lining up with a preexisting map on QGIS

I asked this question once before, but I did not receive any feedback on solving on the issue and I am still confused as to what I am doing wrong. I found a public domain map of Florida counties on ...
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41 views

GDAL c# API returned different WKT from gdalinfo

I've found completely different results in WKT strings while using gdalinfo utility and method from c# API GetProjectionRef(). In the first case the result was: PROJCS["WGS 84 / Pseudo-Mercator", ...
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1answer
63 views

Vincenty or (Project + Euclidean) for accurate distances

I posted a similar question on stackoverflow, however was directed here for more help. If my main goal was to calculate distances such that my error was minimised to the nearest metre assuming that ...
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89 views

How to calculate false easting/northing for Lambert Conformal Conic projection

I'm defining a new GRASS location using the Lambert Conformal Conic projection. My understanding is that the values for the standard parallels and central meridian are dependent on my area of interest;...
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50 views

Transforming lat and long to Mercator x and y

I've been trying to plot a set of lat and long coordinates to a Mercator map using the following set of equations; x = long - long0 y = ln(tan(pi/4 + lat/2)) These equations are from a page on ...