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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2answers
567 views

Adding a custom projection to the epsg.properties

I have created an entry at www.spatialreference.org of a customized .prj file. http://www.spatialreference.org/ref/sr-org/7973/ I'm trying to add the generated geoserver entry to the EPSG.Properties ...
0
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0answers
262 views

gdal read whole geotif band into vector

i have another c++ GDAL question. I try to read alle elevation data out of an GeoTiff file into a c++ vector so that i can get elevation at x,y like this: vector[x][y]. I also like to use this data to ...
0
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0answers
99 views

cs2cs works one way but not the other

I am trying to build a short program using cs2cs that will work on any windows pc I copied cs2cs.exe and proj.dll to a seperate folder When i run this to convert israel tranverse mercator to decimal ...
3
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2answers
765 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 ...
2
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3answers
705 views

C++ coordinate class that automates projection?

Can anyone point me to a C++ class for representing coordinates that automatically handles projection transforms? What I'm thinking of is something that would allow me to create vars that incorporate ...
1
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1answer
754 views

Projecting Imported NetCDF file correctly?

I have 360 NetCDF files (.nc) that I need to import into ArcGIS. They hold monthly historical climate data in the U.S. When I tried to import one, using the Make NETCDF Raster Layer tool, the ...
0
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0answers
58 views

50m x 50m grid around the world

I'd like to subdivide the earth into a grid of approx. 50 x 50 m cells (big database, I know). To make it more complicated (and fun), I also need to be able to determine to which cell a given set of ...
0
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3answers
155 views

Defining custom projection using baseline survey coordinates

I have CAD data that I need to incorporate into a GIS analysis. The CAD data does not have a defined projection, but the drawings include a table of survey baseline points. I need to know if I can ...
2
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2answers
531 views

which map projection should be used for global map with geography and human demographics

I am working on a project to try to identify the most threatened populations (on a global scale) of having a limited access to freshwater. I want to compare those most at risk currently and then add ...
3
votes
1answer
57 views

Why are Google Mercator and UTM rotated towards each other?

Being a self-taught GIS user, I struggled a while before getting the grips on map projections. But now this: because I like to use OpenStreetMap as a background layer for orientation, I have saved my ...
10
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3answers
7k views

How does ArcGIS compute the distance between two points with a non-equidistant projection?

This is a follow-up question to my previous one, Can you suggest some well-written introductory texts about coordinate system projections? Let's assume I'm working with the CH1903 map projection, ...
0
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1answer
2k views

How to use Google Maps projection with GeoDjango/PostGIS

I am building a web service with GeoDjango which involves user submitted events including a location. I created a model field for my location using django.contrib.gis.db: location = models....
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1answer
277 views

OpenLayers Plugin with on-thy-fly-transformation causes wrong coordinates

I am using the OpenLayers Plugin with the maps from Google Satellite. In Qgis I have chosen on-the-fly-transformation into WGS 84. But the WGS 84 coordinates in Qgis are now 0.15 degrees further E ...
25
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4answers
5k views

How does one calculate distortion on Equirectangular Projection?

I am trying to calculate distortion so I can distort overlaying text and forms to precisely match an image of an equirectangular projection. So, how does one calculate the distortion at a given ...
0
votes
1answer
258 views

Copy .prj file into QGIS projection folder

I want a custom projection used in ArcGIS be available in QGIS. I have the .prj file copied out of a ArcGIS folder (containing different projections). Now, I want this file to be added into QGIS. Is ...
1
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0answers
41 views

Get XY in different projection without changing data frame using python addin [duplicate]

I been searching for a way to use this http://forums.arcgis.com/threads/49273-getting-xy-from-mouse-click-using-python tool but print the XY in different coordinate system like WGS 1984 (decimal ...
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0answers
38 views

Problem with projection in meters with ArcGIS 10.1 [duplicate]

I hope you can help with the following problem. I have a shapefile and want to project it using a projected coordinate system with meters as unit. What I did was to change the projection from ...
0
votes
1answer
1k views

Using Fiona to write a new shapefile from scratch

I am new to Fiona, and trying to wrap my head around reading a csv file and writing out an ESRI shapefile. I have most of it down, but am missing two things; (1) defining the projection/spatial ...
0
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1answer
112 views

Political world map texture?

What is correct name of texture and/or projection, which is suitable for 3D engines? I want to apply world map to 3D sphere, but a variety of images found by Google makes me thinks that some of them ...
0
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2answers
93 views

Projecting OpenStreetMap raster base in other projections

I know that OSM WMS service works with EPSG:4326 and EPSG:900913 I need to have an OSM base layer projected in another Projection, for example EPSG:32632 Do you know some way to do this? Even ...
26
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1answer
3k views

How to create an accurate Tissot Indicatrix?

A Tissot Indicatrix is useful method for communicating at a glance the kinds of distortion a given projection is prone to (in the figure below, each of the red circles occupies the same area). I've ...
4
votes
4answers
10k views

Correcting a table's projection in MapInfo

Occasionally I have a MapInfo TAB file that doesn't match up with others. Presumably this is because MapInfo is interpreting it as a different projection to the one it was saved as. I am also assuming ...
1
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1answer
96 views

List the projection & datum of all the files in a folder

In QGIS/GRASS, is it possible to list the projection details of all the shp,tab,dxf files in a folder ? We are having 100 - 150 files in too many folders. We would like to create a table of Proj ...
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0answers
28 views

calculation precision during projection transformation

I am using wgs 84 base tiles, and the tile is not rendered as image but with geojson format. I try to draw them in the tile according to the data. And the geometry of the returned feature is lng and ...
2
votes
1answer
672 views

Why doesn't LeafletJS complete the conversion when re-projecting to Spherical Mercator?

When I use the Mapbox Leaflet pre-packaged Projection class SphericalMercator to project a lat/long coordinate into EPSG:3857 I have to multiply the result Leaflet provides by the earth's radius. ...
1
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1answer
336 views

How to project vector data in QGIS 2.2?

I'm running QGIS 2.2 on Ubuntu 14.04. Trying to project data gives me a hard time right now. The last time I did that was in 2.0 and I basically changed the projection by saving the data as a new ...
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4answers
1k views

Which projection should I use to get my WMS service to work?

All of my shapefiles have exactly the same WKT. Using http://prj2epsg.org I have verified that EPSG:3059 has the same parameters as WKT definition of my shapefiles, so I'm using 3059 in my mapfile. I ...
2
votes
1answer
293 views

QGIS Digitizing in Cartesian

I have a client, that needs some geological maps digitized (polygons) in a Cartesian grid. It would be a basic, square grid with North up, and coordinates in x and y. Some of the maps will need to ...
2
votes
1answer
747 views

Add EPSG:3857 geometries to map using Leaflet

Right now Leaflet can only add geometries with latitude and longitude values onto the map. If we have a EPSG:3857 point, whose x=-11819829 and y=4200860, how can I add it onto the map? If this point ...
1
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1answer
448 views

Importing a DEM in ASCII format into Arcmap - Projection issues [closed]

I've been trying for the last couple of days to import an ascii grid file into Arcmap. However, I'm really battling to project the data. Can anyone please assist? It would be very much appreciated. I'...
1
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0answers
233 views

Calculating closest distances in meters/kilometers given lat/long coordinates?

I am using ArcGIS 10.2 for Desktop. I have a shape file containing points worldwide with lat and long, and another world map polygon file whose Geographic Coordinate System is GCS_WGS_1984 and Datum ...
3
votes
2answers
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 ...
2
votes
2answers
4k views

How to locate a point on google maps/earth using cadastral maps in Kenya

I'm an architect, so not too well versed with all this datum/transformation talk. My little problem: i want to be able to enter a position using UTM or deg/sec/min coordinates into google earth and ...
2
votes
1answer
137 views

Valid values of mollweide projection in QGis

i just imported a vectorlayer (without any reference points) to qgis as mollweide projection to save it to longlat. What i am wondering about is a mathematical problem: Not every x,y coordinate on the ...
2
votes
1answer
432 views

Does ModelBuilder need to use variable to define projection and then re-project?

I am trying to build a Model in ModelBuilder to create two different process raster datasets: One set is to define a raster dataset to set a WGS 84 projection; and then the second set is to take ...
2
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1answer
64 views

Hölzel projection - prj.file

Is there a prj-file-defintion available for the Hölzel-projection? (http://dl.maptools.org/dl/libproj4/manual.pdf#page=58, page 58)?
1
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2answers
850 views

How to fix shape file projections

I have a project with several shape files. The files overlapping however. I have to go to unusable extents to even see the file on the same screen. I have tried using to project to as suggested here ...
8
votes
2answers
600 views

How to get a “classical” globe projection

I have a shapefile of the world continents in EPSG 4326. To what reference system do I have to reproject my file to get a projecting like this globe below?
1
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0answers
49 views

Problems with projections in QGIS 2.2 on a Windows Vista? [duplicate]

I use QGIS 2.2 on Windows 8, and the same QGIS 2.2 has been installed on a computer with Windows Vista. On the Windows 8 everything works just fine, but something is wrong on the Windows Vista. All ...
1
vote
1answer
111 views

Geoserver Reprojection Results in Northerly Shift Compared to GDAL

I have data in a postgresql data store in EPSG:2163 and am displaying that using OpenLayers in EPSG:3857. This results in a ~25 km northerly shift when displayed either in QGIS or OpenLayers. To ...
2
votes
1answer
66 views

Is there general Earth Projection in ArcGIS for Desktop?

I'm starting a new personal project and I need a little bit of helping on setting it up. First off I'm trying to determine the area of a rectangle that is 1 mile in width and the circumference of ...
1
vote
1answer
383 views

My class using ogr to calculate distance is returning incorrect results away from the equator

In an answer to this question ustroetz kindly provided some sample code for use of ogr to do lat/lon distance and point in polygon calculations. I've created a Python class based on his example to do ...
48
votes
4answers
8k views

Why has Web Mercator (auxiliary sphere) become the web map standard?

I understand what the difference is between the Web Mercator projection and Web Mercator Auxiliary Sphere (WMAS). I also understand that both Google and Esri have adopted this projection as their ...
0
votes
2answers
269 views

How to realign misplaced GeoTiffs?

I have bought a few (30) GeoTiff maps from my country's Geo-department - South Africa. They all have a date in the filename and the newest one was created in 2004, I see one is dated 1977 - that old! ...
2
votes
2answers
878 views

Older British Geological Survey geology maps of Kenya; need complete projection information

I have several geologic maps of Kenya produced by the BGS circa 1993. Noted on each map is the following: Projection:-Transverse Mercator Spheriod:-Clarke 1880 (modified) That's great, but that doesn'...
1
vote
2answers
664 views

Predefined Coordinate Systems missing in QGIS 2

in QGis 1.8 were lots of predefined coordinate systems (national projections). Where have they all gone in qgis 2.0? I specifically need the Gauß-Krüger-Projections Zone 1 to 5. Is there any plugin ...
0
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1answer
99 views

Hand-written coordinates from a Garmin NUVI

I've been asked to map point data that was collected in the field by manually writing down the coordinate from a Garmin NUVI 1490 LMT. They were put into a spreadsheet and sent my way which I was ...
2
votes
1answer
174 views

Why this two datasets don't match?

I have a postGIS database in SRS 4326 (WGS84) with several Europe layers working well, but when I load a shapefile projected to the same SRS with QGIS, the layers don't match. To explain it better I'...
5
votes
1answer
185 views

Azimuthal Equidistant - 40,000 Km range

I've been looking at making an azimuthal equidistant map. There are several web sites that offer to make one, based on my location, but they all have the same problem. They assume my antenna rotates ...
4
votes
0answers
34 views

Projecting polygon when calculating its area? [duplicate]

I have a broad range of polygons (in vector format and in SpatialPolygonsDataFrame class), some going east-west, others going south-north, while even others span polar regions or very large ranges as ...