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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Converting u and v from WGS84 to NZTM2000 - Do I need to do vector conversion?

I have u and v wind component values in latitude and longitude in WGS84. I want to convert this to NZTM2000. I've converted the lat/lon in ArcView - (and will try in R) - but do I need to also do some ...
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1answer
51 views

Changing coordinate system says that geotransformation is invalid?

I am planning on using the MODIS burned area products which were produced by Maryland University. These come as either polygons or rasters. In the user guide it says A shapefile version of the ...
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0answers
61 views

Does Leaflet handle TopoJson in OSGB EPSG:27700 projection?

I already have a Leaflet map showing custom base map tiles in British OSGB projection, EPSG:27700 (using the Proj4Leaflet plugin). I would like to overlay some nationwide admin boundary data in the ...
2
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0answers
24 views

OpenLayers measurment path in 31700 projection

I have this code who works great for distance measurment on 900913 projection with 4326 display projection (bing maps + layer WMS): measureDistanceControl = new OpenLayers.Control.Measure( ...
1
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0answers
53 views

Determining printed map projection?

A friend of mine is working on a small project to map receding North Pole summer sea ice minimums by decadal averages on a wall-paper map. Unfortunately, it seems as though the map projection for ...
4
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4answers
174 views

Get a coordinate system from raster file

I am writing a code to loop through all the files in a folder and reproject them, using a raster as the spatial reference. I have a suspicion that there is a different way to get the coordinate system ...
2
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1answer
17 views

WFS Filter performed before or after reprojection?

I'm trying to perform a WFS filter with a polygon in EPSG:3031, (the native projection is EPSG:4326 I think). And I'm aware that WFS/GeoServer supports reprojection on the fly. But will the features ...
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0answers
68 views

Geographic vs. projected raster cell size area

I am wondering the best way of knowing how to define the area of each raster cell in global data. Specifically, I downloaded all ~400 tiles of MODIS land cover data, mosaiced them into one, and now am ...
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2answers
94 views

Coordinates not displaying in UTM

Mac OS 10.9.5; QGIS 2.8.4-Wien; offending data here I want to calculate the centroid of a polygon in meters. However, I cannot get QGIS to display in UTM and I cannot transform/project the data to ...
4
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0answers
60 views

How to choose the EPSG projection?

Up until now for reprojection of my WGS84 vector (.shp) and raster files (.tif), I have been using EPSG projections based on vector/raster central point's UTM zone. But what happens if the ...
1
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1answer
694 views

Layers are of same area but they do not overlap in ArcMap like they should? [duplicate]

For my GIS project for my class, I have downloaded several vector layers from different websites (polyline of the continental divide, a boundary polygon of New Mexico, a rivers and water bodies layer ...
1
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1answer
90 views

Getting inaccurate results converting from New York State projection to NAD83 with Python's pyproj

I've been trying to do a standard coordinate translation between New York State Long Island (ESRI:102718) and latitude/longitude (EPSG:4269)...but I keep getting the wrong lat/lng results. I don't ...
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24 views

Does sinusoidal projection have constant scale factors in all directions?

I know that no map projections preserves all distances. However, looking at the definition of the sinusoidal projection: y = R * phi x = R * lambda * cos (phi) , where R is the radius of earth. ...
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6answers
15k views

Why is the 'straight line' path across continent so curved?

This is the result of mapping the straight line path from a point in US to Poland using Distance Measurement Tool. Also, planes from Asia to US would travel almost over North Pole. Why is the path ...
4
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1answer
185 views

Map projection classification - Tissot's indicatrices are perfect circles, but the projection is not conformal

Recently, led by the perfectly circular shape of the Tissot's indicatrices all over the projection plane, I have concluded that a particular projection is conformal. However, after calculating angular ...
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0answers
39 views

Correcting for offset

I have a shape file with RTK measurements as a line feature, which more or less corresponds with visible features in a raster layer (shaped as lines). These measurements however are not accurate ...
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1answer
774 views

What is/are the coordinate systems used in South Africa?

What are the principal datums and projections used in South Africa including the names of geodetic datums and their projections?
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1answer
30 views

How to read info from the CRS? [duplicate]

I'm struggling to understand how the geo projections work in practice. The info a the CRS is as follows: {'ellps': 'WGS84', 'no_defs': True, 'proj': 'longlat'} Does it mean that the coordinates are ...
0
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0answers
23 views

How to work with a shapefile that has no projection information? [duplicate]

In a shapefile I'm working with there is no information on the projection used. That is, no .prj file. Is there a hack/alternative way of determining what coordinate system the data is in?
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0answers
23 views

Geodesic replacement of coordinates [duplicate]

With a updatecursor I can move vertex to a new location and modify polygons. For a simpele example I tried to move the world, see image. The black lines are the 'edges' of world (180,90 -180,-90 ...
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1answer
75 views

Difference in EPSG:28992 (RD/Amersfoort) definitions

I need to do some projections between WGS84 (EPSG:4326) and the Dutch RD system (EPSG:28992) in JavaScript. I use Proj4js for this. When adding the definition from spatialreference.org I noticed a ...
3
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1answer
58 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 ...
33
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3answers
40k views

Layers with same coordinate system should align/overlap but do not?

I put 4 different layers into my ArcMap document, but only one of them will show up on the map! I should be seeing the other 3 layers as well. When I do a Zoom to layer, I can see one layer, but I ...
0
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1answer
40 views

Reproject non-earth to ITM/ICS

I'm trying to convert MapInfo, non-earth projection, layers with data in ITM or ICS (Israel coordinates in meters). When I do so through Universal Translator with converting to SHP and back again, ...
0
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0answers
24 views

EPSG:4978 or others for Distance

Usually when I have been calculating distances I project to the system which has the tightest crop around my points e.g. for the UK #http://epsg.io/27700-5339 (accuracy: 1.0m) uk = '+proj=tmerc ...
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1answer
480 views

Openlayer plugin in QGIS, error in projection 3857 Pseudomercator

I'm using QGIS plugin Openlayer to set the background of Google satellite under my vector layer. However, even if I project my layers as EPSG 3857 (the default and only possible projection for ...
4
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1answer
61 views

Why can't QGIS handle the Kavrayskiy7 projection although it is supported in proj4?

I'd like to make a world map using the Kravayskiy7, however QGIS seems to be unable to handle the projection, even though it is supported by proj4. 704900 (as is the EPSG for kav7) is not listed in ...
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0answers
19 views

In ArcMap, how much is a Zoom Out click [duplicate]

In ArcMap, when I zoom out (or in) a single mouse-click (not dragging a rectangle, just a click), what is the change to the ratio? If it is different between coordinate systems please explain it on ...
4
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1answer
54 views

Wrong shape display with North_Pole_Azimuthal_Equidistant projection

I need to create a map that displays the breeding and wintering ground of a bird species that has a circular arctic breeding distribution and winters in Africa. The map should lool pretty much like ...
0
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1answer
90 views

Project NetCDF file using GDAL or QGis

Can I project a NetCDF file with the help of GDAL or QGis? The file info is: gdalinfo c:\tomcat-6.0.36\webapps\ncWMS\layers\RAIN_MM_1hour_ac.nc Driver: netCDF/Network Common Data Format Files: ...
3
votes
3answers
77 views

Projection issues with Leaflet - polygon appears off

Using Leafletjs to upload coords from a json file as a polygon. The original coordinates are Vicgrid94(3111). I used QGIS to change the projection to LatLng (4326). When I load the points onto my ...
0
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0answers
29 views

Trouble with Calculate Geometry in ArcMap 10.2? [duplicate]

I got a "Federal Lands" shapefile from nationalmap.gov. I clipped it down to the geography I am focusing on (a few counties in eastern California). I am trying to use the "calculate geometry" tool to ...
0
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0answers
49 views

Why is the project tool in ArcGIS (ArcMap) for desktop throwing the “invalid geographic transformation” error?

I'm trying to reproject a point shapefile from ITRF92 to WGS84 UTM ZONE 14 NORTH. On the geographic transformation input field, I copied and pasted the following geographic transformations from the ...
1
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1answer
40 views

Error distance for coordinate transformation (to WGS84)

I have a dataset with mostly EPSG:31255 and wanted to convert it to WGS84. I now had to realize that the results are up to 100m off when I plot them on a map or just enter the resulting lat lon in ...
3
votes
2answers
59 views

How to calculate area in sq m - troubleshooting projection issues in a global dataset in QGIS

I am using QGIS version 2.12.3. I have 3 polygon shapefiles: A, B and the intersect of A and B, which we can call C. All I want is to add a field to the attributes table of each shapefile giving ...
3
votes
1answer
71 views

Plotting netCDF4 data with the right projection

I guess this will sound simple to you but I just cannot get the right plot within R. I have a netcdf4 file and would like to visualize it within R just like I would do in QGIS and ArcGIS. sample data ...
2
votes
1answer
37 views

Encode an azimuthal equidistant projection in NetCDF conversion

I'm trying to do Azimuthal Equidistant in CF-compliant NetCDF, but I didn't get the correct projection. If you compare the first two information (gdalinfo) you see there is no AUTHORITY and also ...
0
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1answer
216 views

How to create buffer around point having projection 4326

I am trying to create buffer (in meters) around point(long lat alt) which is in projection 4326 with below code. But it is not giving expected output. SELECT ...
2
votes
1answer
45 views

Arcobjects Assign projection transformation to layer file in VB.net

I want to be able to transform a layer from WGS1984 to OSGB1936. I created a tool that extracts layers from several folders on our company network folders, using check boxes that user clicks. One of ...
0
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0answers
18 views

Projecting the Coordinate Systems of layers but one layer doesn't show up with the rest of the layers

I have data from two folders I am working with. Each folder contains shapefiles. The shapefiles in each folder need to have their coordinate systems projected to NAD_1983_UTM_18N. There are 6 ...
3
votes
1answer
55 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 ...
11
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3answers
2k views

Ortho Projection produces artifacts

I`m trying to create a sphere-like view using qgis and the "world from space"-projection http://spatialreference.org/ref/sr-org/6980/ (essentialy an ortho-projection). ArcGIS wraps the shapes ...
3
votes
0answers
76 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 ...
1
vote
1answer
130 views

Convert to lat-lon coordinates GDAL

I have a netCDF file and would like to convert it to LAT-LON coordinates. 1) I do not know the projection in the file but from the website of the data provider, the data is on a polar-stereographic ...
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0answers
32 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 ...
0
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1answer
18 views

calculating ratio of areas on a sphere

I have 2 shapefiles and after identifying their intersections I'd like to know the ratio of intersecting areas, e.g. a given shape S in file1 intersects with shapes (x1,...,xn) in file2 with ...
15
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1answer
1k views

Can Mars be mapped in ArcGIS

Can I use ArcGIS to map planets in particular Mars? Where would I start in terms of basemapping and projection?
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2answers
146 views

Displaying X, Y coordinates on ArcGIS not working

I am trying to geocode some coordinates I have from my Excel sheet onto ArcGIS but everytime I do so, it doesn't show up on the screen. When I right click on the sheet layer to see where it went, it ...
1
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1answer
49 views

Correct Projection for calculating centroids of a group of points?

I have a long list of points covering all of North America for which I would like to calculate the centroid (by grouping points based on the "Name" column). My approach is to take the WGS84 ...
4
votes
1answer
98 views

convert lat/lng to pixel and vice versa

This had been asked previously on Stack Overflow. I've tried different methods/formulas but results are not correct. 40.764296,-73.97302 should result into 930,3590 pixel on map image. I've Manhattan ...