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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235 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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105 views

raster data expressed as percent

I downloaded NDVI greeness data from the USGS Integrated Vegetation Mapping Viewer. In the metadata it says that visual greenness values range from 0 to 100. My data is from the period ending 3/5/12 ...
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621 views

Arc by center point in PostGIS does not fit the circle

I'd like to store a GML ArcByCenterPoint in PostGIS. I can work out the start, middle and end points required by the CIRCULARSTRING type and all seems to be OK, except that when I visualise the arc it ...
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12 views

connecting ecw to its projection and grid data in an xml file

I'm new to mapping please go easy on me:) I have a bunch of ecw files with 2 xml file one is a file ending with *.ecw.xml and one with *.ecw.aux.xml I am trying to load the ecw files into ...
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20 views

Converting Grid to Geographic?

My project specifications are as below: utilise geodetic and shift parameters between WGS84 and specified datum (ED50), local projection (UTM 31N, CM 3 East) and transformation (EPSG1613) for all ...
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27 views

Projection Issues - OpenLayers / MapServer / NAD83 State Plane FT

I am having projection issues with OpenLayers version 2.13 with MapServer and the Proj4 library. Pulling layers in NAD83 State Plane Feet projections on top of an OSM or MapQuest Base Map in Google ...
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22 views

Converting coordinate obtained from google maps to be used with gdal_translate in java or cs2cs?

this is a follow on question from Geo-Referencing an image from google maps with gdal_translate I am trying to get cs2cs to work but I am getting the following error. My command is as follows: ...
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29 views

getting started designing satellite projection raster

How do I get started designing a map with a satellite projection like this:http://bl.ocks.org/joyrexus/6619251. So far using d3 I've created a map of North Africa w/ topojson and tiles from Mapbox but ...
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25 views

d3.js Projection for Washington DC area

I'm making a small thematic map of the Washington DC area using d3.js. Everything I've tried "tilts" the square of DC. Is there a d3 projection that will put DC at the right angle? ...
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38 views

Getting same results from Mapping toolbox of MATLAB as ArcMap?

I am newbie in GEO. I have a point [lat,lon] = [-77.5100 , 166.4000]. I want to find its projection based on equidistant Azimuthal projection method. When I use ArcMap 10.3.1 (with default ...
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137 views

Transforming zonal and meridional velocity from regular lat lon to rotated lat lon?

Like in Transforming regular lat/lon to rotated lat/lon? that was asked before, I am working with climate data and I need to transform zonal and meridional velocities (u and v) from regular lat lon ...
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28 views

Creating equirectangular projection from 3d spatial model?

Apologies if this is not the right group for this question, but I think there may be people here who can help. (I'm open to suggestions for better places to ask.) I have a program that contains a ...
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37 views

Correctness of Measurement

I tried Google, but the questions isn't that easy to put in Google, so I haven't found anything about this. I am making a database with different locations (latitude and longitude). For this I have ...
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27 views

Measuring large distances when all layers are in decimal degrees using QGIS?

I just developed a distance matrix between various points across Canada in QGIS. The distances produced are in decimal degrees, and I would like to view them in metric. I am unsure how to do this.
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39 views

gdalwarp UTM Zone 1 to WGS84 - fails to transform

I have a global dataset consisting of tiles in UTM projection that I want to mosaic and therefore need to reproject to a common projection. Can I solve my reprojection error with options to gdalwarp ...
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45 views

How to align with QGIS two layers that have the same projection?

I am using QGIS 2.12.0 to create forest maps. I usually succeed to create maps from shapefiles with different projections but for some reason I cannot succeed to align the layer of one shapefile. As ...
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32 views

how to fix projection in QGIS from earth data

After downloading and opening natural earth data in QGIS, the result shows like this I have tried uncheck simplify geometry but it doesn’t work. I think the problem is related with globe ...
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25 views

Raster statistics change after re-projection — which one is correct

I'm looking into some global DEMs (like ETOPO1 - http://www.ngdc.noaa.gov/mgg/global/global.html), and noticed that the statistics for the elevation values can change quite a bit after reprojecting ...
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15 views

Geoserver import does not recognize projection

Using GeoServer 2.8 and the Data importer plugin I can import shapefiles generated in ArcMap with WGS84 geographic coordinates (EPSG:4326) and UTM+WGS84 projection (epsg:32724). As a reminder, ArcMAP ...
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35 views

How to test polar stereographic projection for a specific longitude intersection?

I'm writing a library that tests grids defined by map projections for intersections, and am running into an issue implementing the test for polar stereographic and rectangular projections - ...
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20 views

Should I set the projection if the data has already been projected?

I need to plot some data which was produced on a native grid with a lambert conformal conic projection. I need to create a geotiff (using python and gdal) and was wondering how to go about and do ...
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76 views

how to set the geotransform using GDAL in python

I am trying to create an image from a numpy array and georefenrece it so that I can import it into qgis. I have the latitude and longitude in degrees for the top left corner of the array as well as ...
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41 views

problem with area calculation in QGIS

I encountered a problem in QGIS 2.10.1 when I tried to calculate the areas of polygons in a polygon layer. I followed the instructions here ...
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23 views

Projected Coordinate System issue using GDAL and qgis when defining x and y

I have a numpy array which I would like to save as GeoTiff using GDAL in python. The array was created using the following PCS in mind: +proj=lcc +lat_1=48 +lat_2=48 +lat_0=48 +lon_0=0 +x_0=0 ...
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27 views

How can I change the projection used by the QGIS Browser preview?

QGIS Browser has no settings in the UI. Is there any file or so where I can define this?
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58 views

Disparity between QGIS and ArcGIS for Desktop georeference results?

I am georeferencing a static map in JPEG format. I would prefer to use QGIS for a variety of reasons. I've never georeferenced with QGIS before, so I may not have the process quite right. I ...
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24 views

Loading AHN files correctly into MicroDEM?

In the netherlands we have the ahn elevation data files(to be found on: http://geodata.nationaalgeoregister.nl/ahn2/atom/ahn2_05m_ruw.xml) (based on rd projection). If i imort these files into ...
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22 views

Sinusoidal Projection and ArcInfo Sphere Datum Woes

I am using published forest loss data (found here: http://glad.geog.umd.edu/indonesia/data2014/index.html) that uses the ArcInfo Sphere datum with a sinusoidal projection. I am seeking to transform a ...
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32 views

Data not showing in QGIS when connecting to Oracle

I have an Oracle XE 11g spatial database that is connected to a web map. All the layers of the web map are stored in the database and they work just fine. I sometime need to edit some of the layers in ...
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32 views

GPS point elevation vs Contours layer elevation

I have some survey grade GPS points whose elevation is approx 55 feet lower than my contours layer elevations. I am using 1 ft contours and comparing point elevations with contours in the same ...
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63 views

Matching d3.js geo projection with pyproj Proj4

I am having trouble figuring out the correct notation for Proj4 projections with pyproj. I got the following projection in d3.js and I want to match it with pyproj on my backend to send a background ...
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48 views

Projections way off on data imported into QGIS?

I have elevation data as a .shp from the USDA ARS and Hi-Res Orthoimages (Mystery Projection (UTM 15N?)) from the USGS website as geoTIFFs (plain NAD 83). I am trying to project all of the images ...
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155 views

How to project WRF data (lat/lon) onto ArcGIS maps

I have climate data generated using the WRF model, in lat/lon format (lambert conformal projection), in an Excel file. I'm looking to project / overlay this data onto a map of the UK using ArcGIS, ...
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89 views

Rectangular bounding box curved in D3.js

I am trying to project polygons to a map with a static background image using D3.js. The polygons looked slightly off in relation to the background so I drew the bounding box of the image, and sure ...
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51 views

Converting coordinate system of feature layers and datasets programmatically

I am trying to convert coordinate system of featurelayer and datasets using ESRI.ArcGIS.DataManagementTools.Project . The tool works fine in ArcCatalog . I have doubts about the parameters i am ...
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59 views

project hdf file with geospatial_lat and lon in batch process

Is there any way that I can do a batch process in projecting hdf files wherein I could get and include only the geospatial_lat and lon in the batch script since every hdf file have different ...
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57 views

Spherical Mercator - World bounds

What are the correct world bounds in the Spherical Mercator projection (EPSG:3857 and EPSG:900913) In some source I got those bounds see this link in the maxExtent parameter: minx: -20037508.3427892 ...
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208 views

How does OpenLayers 3 handle coordinates?

Ol3 always uses the flatCoordinates because obviously it needs 2d-coordinates as the screen is only 2-dimensional. But how does OL3 calculate the flat representation? For example if my view’s ...
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48 views

Zonal geometry output in ArcGIS

Is there a way to specify the coordinate type in Zonal geometry output in ArcGIS? I am trying to perform zonal geometry on a raster and in the resulting output, the XCENTROID and YCENTROID are in ...
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73 views

ESRI/Mapinfo MGA56 prj vs QGIS MGA56 prj

I am trying to understand why the degree unit is different between ESRI/Mapinfo and QGIS: ESRI/Mapinfo ...
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90 views

Raster overlay with different projection in Google Maps

I have a map created with Google Maps. I want to overlay over some data I am downloading dynamically, covering the whole world. That data is a matrix as follows: 1024 values for the longitude ...
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60 views

Which projection should be chosen to model transmission lines across the USA?

I am looking at different options for high voltage power lines in the US. These power lines cross several states. Since in the end the distance is of importance, is the USA Contiguous Equidistant ...
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22 views

Changing Area Output - PUMAS

I currently have shapefile of US PUMAS and another feature shape file (call it feature X). I am using arcpy to project both of these files to the following projection coordinate system (using ...
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24 views

QGIS - Label polygon with different projections

I have a polygon layer projected in an UTM. In properties I checked 'show all labels for this layer'. Does anyone know why the label does not show until zoom 15:1 in QGIS with CRS-4326, while in ...
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84 views

Unknown coordinates in Shapefile, projecting doesn't give expected results

I'm reading a Shape file (four files actually, .dbf, .prj, .shp and .shx) containing polygons representing certain areas in my neighborhood. For this I use C# and a library called DotSpatial. I can ...
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296 views

Length difference between Google Earth and ArcGIS for Desktop?

I have drawn a complex path with multiple vertices in Google Earth (GE) Pro and its measurement property is shown as being 2,460 nm. It is located East of Australia. If i import this KML into ArcGIS ...
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35 views

Resampling methodology when projecting a raster

When projecting an SRTM raster with "Project Raster" tool in ArcGIS10.2, what is the best resampling methodology, bilinear ot cubic convolution?
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46 views

QGIS (2.0.1): Field calculator for length not working - values way too high

Same problem as another thread: Field Calculator returning incorrect length and area values Trying to calculate length of a line shapefile, and field calculator is returning values that are way too ...
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197 views

Show a kml (which uses longitude and latitude EPSG:4326) in “google/OSM” projection (EPSG:3857) in open street map

I am showing a kml layer, over OSM. The points in the kml are latitude/longitude (EPSG:4326). I don't have to convert any points or anything, it all just works. Great! Now, the client also wants to ...
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191 views

Projection problems when importing .kml from Google Earth to QGIS

I want to open several points that I exported from Google Earth as a .kml in QGIS for further use. I can import the data and the points are displayed but something must be wrong with the projection as ...