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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Raster Layer doesn't display, TileMill

I'm attempting to add a raster layer to TileMill, but for some reason the raster doesn't seem to be reading in correctly. I used gdalwarp to reproject the raster file to EPSG:3857 and then import it, ...
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2answers
4k views

How is EPSG:4326 data 'projected' in a 2D map?

I like to think I'm relatively well-versed in datums, projections, and coordinate reference systems, so if this is a stupid question I will suffer eternal shame. OpenStreetMap data is stored in WGS84 ...
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1answer
38 views

Plot a world heat map with mollweide projection in R

I have a data set with global observations with lat/lon information. There are 288 longitudes from -179.375 to 179.375 with spacing 1.25, 180 latitudes from -89.5 to 89.5 with spacing 1. There is one ...
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1answer
648 views

OpenLayers and custom Proj4 Projection

I am trying to map some planetary data on my webMap server using OpenLayers. I defined a proj4 projection as follow: Proj4js.defs["MYDATUM"] = "+proj=longlat +a=1740000 +b=1740000 +units=m +no_defs"; ...
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1answer
33 views

Restore previous versions of Qgis file

I´m trying to recover a previous version of a Qgis file, because I started playing around with CRS, and saved the file and closed it, thinking next time it woud be easy to get everything back into ...
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13 views

Two layers of the same region with the same coordinate system does not lay in the same place! [duplicate]

I know that my problem seems to be frequent but I couldn't find any good till answer. I have two layers for the same place (area and roads) in my ArcGIS, both of them has the same coordinate system ...
9
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1answer
659 views

Georeferencing LAS files in geographic coordinates (lat/lon) or in cartesian (projected) ones?

First of all, I am a newbie in GIS. I have a lidar point cloud with GPS and telemetry data associated. Then, I transform coordinates of every point to an ECEF coordinate system and finally I ...
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2answers
699 views

Getting the projection of a LAS file using liblas?

I am using the python api of liblas to read/write las files. I would like to get the spatial reference information of the las file using liblas, but have been unable to figure it out. Can anyone ...
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1answer
432 views

Get Radius in epsg 4326 with Openlayers 3

What is the best method for getting the radius of a circle in Openlayers 3 in epsg 4326 (geodesic)? I'm using this example for a base and trying to draw a circle while getting the radius, but using ...
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31 views

R Levelplot overlaying two SpatialPolygonsDataFrame on a RasterLayer

I'm having some trouble plotting a RasterLayer and a SpatialPolygonsDataFrame in a level plot in R. Something is wrong with the projection, but I don't manage to understand what. Here you can find my ...
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Importance of CRS in Getis-Ord Gi* hotspot analysis

I have a question about the importance of the chosen CRS in a Getis-Ord Gi* hotspot analysis - I am running a hotspot analysis (using Zone of Indifference spatial relationship) on a quite restricted ...
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0answers
28 views

Which SQL Server spatial data type to use for UK data in SQL Server?

Which spatial data type should be used for UK data in SQL Server?, i.e. GEOMETRY or GEOGRAPHY? I'm aware of OS National Grid and my understanding is it's an X/Y coordinate system, covering from ...
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0answers
65 views

Problem aligning historic map of Poland [closed]

I have downloaded a historic map of Poland. I am having a problem aligning it to a modern map. I have tried various methods and coordinate system using over 50 points, but nothing works. It gets close,...
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1answer
162 views

What is my coordinate system preserving?

I'm trying to get a better grasp of coordinate systems, datums, projections etc. I understand that certain systems preserve different things; distance, shape, angles, area. I'm wondering how you can ...
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1answer
90 views

Put points on a projected world map

With the help from this post Lines on reprojected sp objects with Mollweide projection, I draw a world map using Mollweide projection. I also have some points with latitudes and longitudes, and I ...
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1answer
38 views

Assigning CRS using las2las from libLAS?

My las file had a spatial reference of "None." I tried to assign the CRS (in which data were collected) with the following command line: las2las flightline_002.las --a_srs EPSG:32632 lasinfo --no-...
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1answer
968 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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2answers
1k views

GDAL/proj4 equirectangular projection coordinate system units assumed by OGRSpatialReference and GDALDataset::GetGeoTransform()?

How do I configure my OGRSpatialReference object to specify an equirectangular projection system http://en.wikipedia.org/wiki/Equirectangular_projection where the affine geo-transform matrix (provided ...
2
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0answers
23 views

ArcGIS project raster mosaic bends the raster but not the footprint when projecting

I have mosaic whose rasters are using a custom coordinate system: US_IFR Authority: Custom Projection: Lambert_Conformal_Conic false_easting: 0.0 false_northing: 0.0 central_meridian: -95.0 ...
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0answers
17 views

Reprojecting and Aggregating a 30m resolution raster to a 3 arcsec raster

I am a using a 30m x 30m resolution land use raster that is projected in NAD83 Québec Lambert but would like to convert it to make it compatible with a 3 arcsecond flow accumulation raster that is ...
2
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0answers
47 views

Getting Error 000151 from ArcGIS Projection?

I'm having big problems with arctoolbox of ArcMap 10.3.1 to project almost all my layers from TM65 - Irish Grid to IRENET95 - Irish Tranverse Mercator.I always get the error 000151 and the Help is ...
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1answer
36 views

Area calculations using a layer in a projected data frame versus a projected feature class in ArcGIS

So I've been tasked with automating a formerly manual process in model builder in which I'm trying to calculate land area. In the former manual process the feature class was brought into ArcMap and ...
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0answers
39 views

Gdalwarp UTM reprojection causes image distortions

I'm trying to re-project Sentinel-2 images to a common UTM zone in order to create a mosaic. For this I'm using gdalwarp with the following syntax: C:/OSGeo4W64/OSGeo4W.bat; gdalwarp -t_srs \"+proj=...
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1answer
50 views

Produce Oblique Mercator Map

To avoid the possibility of opinions, let me rephrase the question. Which software packages are able to produce an Oblique Mercator map between any two arbitrary points, similar to what is offered in ...
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2answers
102 views

Reproject raster without projection info

I'm pretty new to gdal and got a presumably easy question for experienced gdal users. My problem: I have a raster ascii file of which I don't know the projection or epsg code. However, I want this ...
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1answer
24 views

Web Mercator to 3d globe projection problems

I've been trying to use map tile images from services like OpenStreetMap to create a globe, and I've mostly succeeded. The problem is that when I compare my globe to one using the same image source ...
2
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1answer
44 views

Problems with matching vector data with raster data

I’m new in Arcgis, and I have some trouble in this task: I downloaded from ICC (www.icc.cat) a raster data map that is a in a specific coordinate system, if I right click to view its properties, it ...
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2answers
224 views

Defining coordinate reference system with rotation in GeoServer?

I am using GeoServer and have a layer in EPSG:900913 ("Google Mercator"). I need to "rotate" the map around certain point (say, 1500000, 7000000) by certain degree (say, 30 degrees clockwise). How ...
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2answers
45 views

D3 can't render GeoJson file (Simple structure in Montreal, Canada) created in QGIS

I am attempting to render SVG and attach it to a div with id="map". I can do this successfully with GeoJson which I acquired from this tutorial: http://maptimeboston.github.io/d3-maptime/#/1 Excerpt: ...
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2answers
83 views

What kind of projection is this?

Can someone tell me what the projection is in this zone map from NOAA? I am trying to replicate it (or get close) in QGIS.
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1answer
20 views

Discrepancy between shape area and data from municipality [closed]

I am attempting to map several parcels just to show very basic dimensions (frontage, etc.) and parcel area. I have the parcel area from the municipal assessor's office in acres. And I have a parcel ...
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1answer
40 views

Can gdalwarp reproject from ESPG:4326 (WGS84) to UTM?

I've a GeoTIFF image in ESPG:4326 (WGS84) and when I try with gdalwarp to reproject to UTM, it has problem gdalwarp -s_srs "EPSG:4326" -t_srs '+proj=utm +zone=33 +datum=WGS84 +units=m +no_defs' -of ...
2
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2answers
65 views

OpenLayers 3 / Cesium polygon projection issue

I am using OpenLayers 3 and Cesium (via ol3-cesium). I have created a few rectangles (using a MultiPolygon) stacked on top of each other. Whereas in OpenLayers the rendering (left) is as expected, ...
2
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2answers
100 views

Is it possible to restore lost PRJ-Files?

Currently I am working on a project with QGIS (2.14.1). Therefore I need to add old (but important) shapes that were drawn by a colleague. Somehow most of the .prj-files are missing - I don't know ...
4
votes
2answers
98 views

Openlayers 3 connecting to a wms feed with a different projection

I am trying to incorporate a wms feed in the British national grid projection (EPSG:27700) into a openlayers 3 project. I initially had used this wms layer in an openlayers 2 application using the ...
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0answers
43 views

Creating Proj4 string for local coordinates

I am fairly new to coordinate system conversion, so am rather lost on the following problem. We have been using Proj4 to convert between various coordinate systems which is fine for known coordinate ...
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1answer
72 views

Check if point is within radius of another point with Shapely

I've successfully used Shapely with python to check if a point is within one of a set of polygons in a .shp file but now would like to check if a point is within a circle of radius x miles from ...
1
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1answer
31 views

R: Krovak projection in R - identical in ArcGIS, different in R?

I have two files: shapefile and raster, both in the same coordinate system in ArcGIS: EPSG 5514. Check information on projection in ArcGIS for raster: S-JTSK_Krovak_East_North WKID: 5514 Authority: ...
2
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2answers
276 views

Mapping Russia - Int'l dateline splitting polygon

I am having the issue where the International Dateline is splitting a polygon I am working with. I have a layer of the "Federal Districts" of Russia, and the eastern most federal district is being "...
4
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2answers
586 views

Project twitter geo data into WGS84 map

I'm currently working on displaying twitter geo data (currently just long/lat -> cartesian without any analysis). This is the world map (source: naturalearthdata): http://dl.dropbox.com/u/14747311/...
5
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1answer
2k views

Projected maps should but do not overlap in ArcMap? [duplicate]

I am very new to ArcGIS and trying to build a series of layers of data in ArcGIS 9.3.1 for a river catchment in Leicestershire, using data from several sources. All data covers at least the area of ...
9
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3answers
5k views

Shapefiles and OpenStreetMap data do not overlap in QGIS?

So I'm pretty new to GIS, and I'm working on a mapping project using data for Vancouver, Canada. I want to combine OpenStreetMap data along with data provided by the City of Vancouver. But the City ...
0
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0answers
6 views

How do I display NAD 1927 Albers with other data?

I have some raster datasets which are in NAD 1927 Albers projection. I cannot seem to display any other type of data with this projection. I get the pop-up projection warning when trying to add a ...
3
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0answers
22 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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0answers
21 views

RD new to WGS 84 conversion

i want to display 2d building shapes and 3d buildings as presentation purpose.i m using Arcglobe for it.i have shape files with projection EPSG:28992.i have converted it into WGS 84 but my shapes does ...
2
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0answers
38 views

Re-projecting shapefile from an unknown projection [duplicate]

I have been given a shapefile which is supposedly in a NAD1927_Zone16 projection. I need to align it with a raster image in a Lambert Conformal Conic (NAD 1927) projection. I've tried to use the ...
3
votes
0answers
74 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 ...
2
votes
0answers
37 views

Calculate Geometry function returns underestimated distances

I'm making a map of the Colorado Trail and obtained a set of waypoints taken down the entire trail. I projected the set of waypoints from WGS84 (unprojected) to NAD 83 UTM13N after adding to the data ...
3
votes
1answer
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 ...