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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501 views

ArcGIS / ArcMap problem with tiff file and projection

I have a raster in ArcMap . The projection is WGS 1984 UTM 22. When I look the details of the projection I can see that the "scale factor" is 0.9996 When I save this raster in a in tif file and the ...
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2answers
284 views

will ogr get coordinates in geographic coordinate system or projected coordinate system when using getPoint(int,OGRPoint*)

Consider the code that I have written in the stackoverflow question How to extract vertexes of geometries in ESRI shapefiles using ogr library with c++, I have used the code to show shapefiles on an ...
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37 views

Differences between points and lines as poles in an equal area projection

I am planning on using an equal area projection in a current project. I used this website to determine which projection I should be using. I hadn't previously considered it, and was wondering if ...
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0answers
95 views

Recommendations on universal projection API or algorithm for ArcObjects?

As asked on the esri forum here, we are trying to convert a geometry from any spatial reference to any other spatial reference. We have tried the default IGeometry.Project(target_spatial_reference) ...
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2answers
626 views

How to add new projection using ArcObjects of ArcGIS for Desktop?

I want to use "Mars MOLA" { 86 3396000.0 3396000.0 "Mars MOLA" 0 0 0 0 0 0 0 } with my shapefiles.
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1answer
593 views

What's the correct transformation for Lambert Conformal Conic for Mexico?

I have a shp archive without the .prj file. I don´t know the proyection of this shp, but I think it is in lambert conformal conic. Can anybody helpme to proyect this shp? i´ve tried to proyect it in ...
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0answers
177 views

Am I correctly projecting a geometry using a WKID in ArcObjects?

I would like to take in any valid WKID for a spatial reference and then project a single geometry to it. The following code seems to be working, but (1.) can someone verify that this is the correct ...
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1answer
353 views

QGIS Georeferencer, unexpected transformation, and GCP placement

Im trying to get the sample map which i believe to be EPSG:3112 into QGIS and geo referenced. In my screenshot, on the right is the raster in georeferencer with the points i have added. On the left is ...
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1answer
176 views

Mapguide and OpenLayers SRS WKT

I am trying to create OpenLayers vector features based on WKT strings that I retrieve from a MapGuide server. I have successfully gotten the proper geometry to be rendered, but I do not know how to ...
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2answers
799 views

Projections appropriate for global analysis that preserve area and that preserve distance (but not necessarily in the same projection)

I am looking for a projection (or a set of projections) that decently preserve distances so that I can buffer every country in the world and have a similar level of minimal distortion for each. I ...
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0answers
528 views

Help me convert this US Lambert Conformal Conic Google Maps Projection to Australia

Following on from this question: Identify what projection this Australian map uses? <- this is the sort of map i want to load in I need help changing the bits necessary in this example of Lambert ...
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0answers
2k views

How do I change from lat/long to a metric coordinate system in GRASS?

Yes, it's yet another transformation question. I am working with ASTER DEM data, which is LatLong WGS84. I want to process the DEM map into an STL file for use in a CFD simulation. The script I am ...
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2answers
858 views

Identify what projection this Australian map uses?

Im looking to put this map into google maps as custom tiles, but i now learn what projection is and that this map does not use the same format as google's default. You can create custom projections i ...
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0answers
168 views

Sort a collection of points based on proximity using pythagorean (2D) distance

I would like to present a user with a list of points, sorted by proximity to the user's location. Is there any problem with using the pythagorean formula to calculate the two dimensional distance ...
3
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1answer
677 views

How to get spatial reference of a shapefile using python?

I always use arcpy.GetParameterAsText to get the spatial reference from the user. There should be a way to decide what is the spatial reference of a shapefile but I can't find it. Something like ...
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1answer
998 views

How do I project a Azimuthal Equidistant global map into a circle in QGIS?

I'm fairly new to QGIS/GIS stuff in general, so I apologize if this is too simple of a question, and I'm just bad at finding my answer. I have a shapefile of all the countries in the globe I ...
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2answers
2k views

What is the standard Mercator projection?

I'm using QGIS in order to re-project a shapefile I have into "Mercator" so that something like protoviz understands my co-ordinates. Protoviz tells me "Mercator" ...
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1answer
745 views

How to make SVG Stabius-Werner projection

I'd like to create a SVG file of a Stabius-Werner projection of the Earth. The image in the linked page is nice in that it's very high resolution (2,058 x 2,065 pixels), but I'd like to see if I can ...
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1answer
95 views

Images displaced in UTM

I recently received a collection of satellite images (GeoTiffs) and their indice. Originally, the indice came in a geographic projection (GCS WGS 1984) and the Geotiffs projected to the appropriate ...
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0answers
791 views

How do I redefine the projection of a DEM?

I have a DEM that was exported from AutoCAD civil 3D 2013 but it's in the wrong projection. I'm using an area specific projection that was not provided as an option in CAD DEM export dialog box. I ...
2
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2answers
711 views

Is it possible to reproject KML using ESRI's Javascript API?

Specifically into NAD83. Google tells me that KML only supports WGS84, but I can't seem to find much info on being able to reproject KML using ESRI's Javascript API. Basically, I've got this base ...
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1answer
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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0answers
90 views

Van der Grinten IV projection. Is it possible and how?

I like the look of the Van der Grinten IV projection with it's two hemispheres and would like to use if for a map of the world. I could only find information on how to use the Van der Grinten I ...
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1answer
504 views

GIS - Coordinates / Projections, Google Maps

I'm currently working with OS data and have just tried to import a table of google maps coordinates/point data into ARC. The data frame (& layer) coordinate system is as follows: ...
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2answers
394 views

How to use OpenLayers OSM-Layer with degrees instead of meters?

I have an OSM-Layer as a base layer. When I create a vector I have to define the coordinates in meter. Is there a way to use degrees right a way without reprojecting them beforehand to meters? var p0 ...
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2answers
1k views

How to create an Azimuthal Equidistant map for long-distance radio?

I'm trying to produce world or continent scale maps that use the Azimuthal Equidistant projection. I'm a radio amateur, and to an antenna, the whole world looks like spread out on a flat plane, with ...
6
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2answers
778 views

Is it possible to use the Goode Homolosine projection in QGIS?

Is it possible to use the Goode Homolosine projection in QGIS? Both QGIS and GRASS seem to have trouble with the interruptions, squashing the higher latitudes together. I tried +proj=goode ...
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4answers
752 views

Which UTM system do you recommend for Tamaulipas, Mexico?

I'm working with QGIS 1.8.0. Could anyone tell me which UTM system would be better to project a map of Mexico? There are too many to choose from. I have to convert my maps from WGS84 to UTM to do some ...
3
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1answer
864 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). ...
3
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1answer
774 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) ...
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2answers
178 views

Projection 27700 in the OpenGeo Suite SDK GXP

I have some data stored as UK grid references, they display just slightly off alignment on the map after I followed the OpenGEo EXP tutorial using these settings (below) however when I change the EPSG ...
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1answer
32 views

Network segment gaps, when offset

I'm having an issue when offsetting a line shapefile. For some reason when the lines are offset, ArcGIS isn't drawing some segments although the segments are there confirmed via “identify”. Has ...
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1answer
88 views

Why isn't enabling on the fly projection reflected in raster? QGIS 1.8.0

I have imported a map from the Ordnance Survey Open Data website. It is a 50k Street View raster. I have also created a new shapefile layer in which I have created a polygon overlay for the raster ...
0
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1answer
273 views

What SRID is this projection?

Anyone know what the SRID is for the following projected coordinate reference system: { PROJCS [ "Florida 0901, Eastern Zone [1983, US Survey feet]", GEOGCS [ "NAD 83 ...
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1answer
170 views

Albers Conic versus State Plane Zone in terms of accuracy

I'm trying to determine if an Albers Conic (Alaska Albers) is suitable as a projection for a corridor 800 miles long by 50 miles wide, that goes from the north coast of Alaska to the south coast. ...
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3answers
2k views

What is a good projection for the whole of China (with units in meters)?

I get some GPS results which lay in China with WGS84 coordinate system, and I need to choose a projection to reproject for. First I chooses the UTM projection, but I find the results lay in ...
3
votes
1answer
2k views

Setting coordinate system in PostGIS

The geographical information data that INEGI (part of the Mexico's goverment) provides are in the following coordinate system (or is projection?) Lambert Conformal Conic, double standard parallel ...
2
votes
1answer
128 views

Using ogrinfo to list all projection source of a database [closed]

I have to reproject all the layers from a database, but some of them are undefined and some are defined in a wrong projection. I would like to sort all those layers in a text file with their source ...
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1answer
315 views

Working with Interrupted Goode Homolosine data

I'm trying to use Global Land Cover Characterization data from the USGS: http://edc2.usgs.gov/glcc/fao/data_specifications.php It is in the Interrupted Goode Homolosine projection. As I am working ...
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0answers
30 views

How to quantify projection distortion using ArcGIS [duplicate]

I am trying to figure out a workflow to quantify the amount of distortion for different projections throughout a given area of interest. I am thinking in the form that you would do a relative ...
2
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0answers
217 views

Mercator projection that shrinks toward pole

I've noticed that lots of map viewer (especially those nautical chart viewer) will shrink a mercator projected chart while panning towards poles. Is this some compensation for mercator distortion? ...
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1answer
348 views

Openlayers and KML layer projection issue

I'm not a GIS expert at all, but I've been asked to add a KML layer to an Openlayers map which probably needs some tweaks and that's where I get confused. Let say I have an Openlayers map with the ...
3
votes
2answers
6k views

Choosing the correct value for proj4string for shape file reading in R “MapTools”

I am having a shape file of polygons and another CSV file which contains a list of points as (Lat, Lng) pairs.. I want to check for each (lat, lng) pair from the CSV file which polygon does it fall ...
2
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1answer
835 views

EPSG:4326, EPSG:3857, JOSM and unprojections

It is said here that EPSG:4326 is not a projection. In my mind, a projection is a transformation of the surface of the Earth producing a flat image, notably a bitmap. We know that WGS84 (World ...
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1answer
955 views

How to make polygon shapefile containing WGS 84 UTM zones as features?

I need a shapefile with polygon features. Each feature has to be a unique UTM zone (each zone is 6 degrees) in the northern hemisphere. I have no idea how to make it - Create fishnet gives a wrong ...
8
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3answers
2k views

Distance measurements across UTM zones: use geographic or planar approaches?

I have a survey grid spread across 3 UTM zones (36N, 36S, 37S). I want to find the nearest (or shortest) distances of the centroids of these grids to roads and various points between. It seems like ...
3
votes
3answers
2k views

What is the formula for calculating world coordinates for a given LatLng in Google maps?

I want to calculate a given LatLng to the world coordinate . I know I can use the internal projection of Google maps like this: var map=new google.maps.Map(...); ...
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0answers
202 views

Map doesn't show anything in img file (WMS-Mapserver)

Actually in a practical Project we wanted to use OpenLayer and MapServer to display our data using WMS, but We can't find a proper srs or EPSG code. One of the ITC students said, we have to change our ...
0
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2answers
699 views

Calculation for conversion of Lat/Lon to World Geographic Reference System (GEOREF)

Does any one have a reference to, or the actual code, to convert Lat / Lons to Georef code (http://en.wikipedia.org/wiki/Georef)? I am also interested in finding a conversion from lat/lon to MGRS. ...
2
votes
2answers
2k views

How can I use GDAL to batch define a projection?

I have a fodler with 1500 ECW rasters, no spatial reference information defined. Can I use GDAL to batch define a projection for all 1500 in the folder?