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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How does ESRI, and how should anyone, transform a coordinate that lies outside a grid transform (e.g. NADCON)?

As I understand it, a datum transform (e.g. urn:ogc:def:coordinateOperation:EPSG::1241) based on a grid interpolation method, e.g. NADCON, is undefined outside of the grid of points. Therefore the ...
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36 views

What is the SRID of LCC projection?

I have a raster file with LCC projection and a point dataset with SRID 4326. I want to extract raster value to point. When I use the query SELECT ST_Value(rast, geom) val FROM testraster5, ...
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48 views

What is the real distance between positions?

I'm trying to figure out what gives me the most accurate distance between positions: Measuring distance directly (using Geod.inv)? Measuring distance in 2D (after transforming to a known projected ...
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1answer
53 views

Geo-Referencing an image from google maps with gdal_translate

I am trying to geo-reference an image using gdal_translate in a command prompt. Currently I have the following gdal_translate.exe -of GTiff -a_nodata 0 --config GDAL_DATA "Config location" -a_ullr ...
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93 views

Projection for Calculating Distances in Continental United States?

TL;DR Question: I want to calculate distance from point to edge of nearest polygon for 2,000 points in Continental United States. What is the best projection to use? Full Question: I have two ...
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158 views

MMQGIS:Create:Hub Distance: Output shapefile in wrong coordinate system

I have a QGIS-project that is completely in EPSG:31467 - DHDN / Gauss-Kruger zone 3. It consists of random points (camera traps) surrounded by a polygon (forest edge). I already converted the polygon ...
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1answer
75 views

Equatorial Scale

I have seen Equatorial Scale written along with the RF on the World Map in many Atlases, for eg., "Equatorial Scale 1:95 000 000". What does this Equatorial Scale mean and what is the significance of ...
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2answers
122 views

Google layers not matching

I'm working in a project with whole Europe data. I'm working with WGS84 (4326), and sometimes I overlay my polygons with Google maps layer (in QGIS) to see some details. When I do this, I have to ...
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96 views

Choosing projection to use for Least-Cost Path analysis at continental scale?

I am trying to find least cost paths from the southern USA to the Great Lakes region (for example). My resistance layers are currently in an equal area projection but I'm wondering if I should convert ...
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1answer
498 views

QGIS not interpreting Lambert Conformal Conic projection correctly

I'm a fairly new user of QGIS and I've run into an issue that I can't seem to solve on my own. I'm trying to work with the NRCan Atlas of Canada Waterbodies SHP file but I'm having an issues ...
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1answer
191 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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128 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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201 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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1answer
863 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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171 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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1answer
1k 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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1answer
632 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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1answer
209 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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1answer
558 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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1answer
177 views

How to bulk import ESRI projections into Postgis

Where can I get a file that would allow me to bulk upload all of the ESRI projections into the spatial_ref_sys table of postgis. I know that you can get insert statements on spatialreference.org; ...
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1answer
1k 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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1answer
724 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 ...
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703 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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698 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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1answer
682 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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48 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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1answer
96 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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1answer
173 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 ...
3
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1answer
213 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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1answer
249 views

Projection mismatch when plotting precipitation with ggplot

I'm trying to plot accumulated precipitation in Brazil for a given period, see code below: Load packages library(raincpc) library(SDMTools) library(raster) library(ggplot2) library(rgdal) ...
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456 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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810 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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351 views

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

I have a shapefile with the following .prj file: ...
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1answer
189 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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333 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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1answer
49 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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2answers
6k 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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1answer
773 views

Find projection of a point to a 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) ...
3
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681 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? ...
3
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1answer
162 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 ...
3
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1answer
439 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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423 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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2answers
225 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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1answer
378 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= ...
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782 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
366 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
29 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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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 ...
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40 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 ...