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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Creating spatially projected polygon grid with ArcMap

i need to create a grid with 1x1 square kilometres cells in ArcMap. The operation located in Data Management Tools -> Feature Class -> Create Net is almost what i need but in the parameters, i can't ...
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1answer
393 views

Using customized Coordinate System for Archaeological site data

I don't know so much about coordinate systems... In my office we use to deal with spatial data coming from archaeological sites. Each site has its own x-y-z coordinate system (GCS). Three simple ...
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5answers
5k views

How can I measure area from geographic coordinates?

If I have polygons in geographic coordinates (WGS84), how do I measure the total area each takes on the surface of the earth, taking into account the curvature of the earth?
2
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1answer
80 views

How to transform this PostGIS type of projection to EPSG:900913 in OpenLayers?

I have transferred this kind of projection from this type(which I don't what type it is): 010100000054E077E6F8F33640FD87F4DBD7AD4340 to EPSG:900913. I have the points which are in the above format ...
2
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3answers
250 views

Geodesic measurements for short distances throughout US?

My ArcGIS experience has been limited to working on large-scale maps with planar projections. I'm moving to a project in which I want to calculate the distance between pro sports facilities throughout ...
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2answers
92 views

Mercator vs. Web Mercator for Large Scale Topographic Maps

I have 8 terabytes of imagery that is in either lon/lat or UTM projection that I will be using for the basis of large scale topographic maps. I have been studying the differences between Mercator and ...
3
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1answer
259 views

1944 Cyprus Grid coordinate data projection problem in MapInfo

I have coordinate data from the 1944 British Army General Staff, Geographical Section (GSGS) Cyprus map which was cast on the Cassini projection, but was referenced to the Clarke 1880 ellipsoid where ...
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2answers
138 views

How to store lat/long in PostGIS database? [duplicate]

I have a bunch of points in a text file that are represented using lat long (116.3158516 39.9748016). I import them into my GIS enabled database and create trajectories using st_makeline() as ...
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3answers
284 views

How to manually change from GPS (WGS84) to web based maps projection systems?

I have collected location point data and wish to display this on a web based map. It was collected using a Garmin Etrex GPS using the WGS84 datum. I wish to display the points using Ushahidi and have ...
9
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0answers
157 views

How do ESRI and QGIS calculate scale values of geographic projections? [closed]

Does anyone know how (from which location) scale values are calculated in ESRI products and QGIS for geographic projections? The only thing I've noticed is that QGIS is changing scales when you pan ...
3
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2answers
233 views

Reprojecting a base map in ArcGIS

I am new to ArcGIS. I have the EDN license (Desktop and Server); have setup ArcGIS for Server in our offline environment; have published several base maps (with caches that ESRI provided me on a DVD) ...
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0answers
39 views

QGIS CRS correct, but layers appear warped

I am trying to overlay a raster Landsat 8 scene and vector scene boundary. Both are using WGS 84 + UTM48N. However, the vector (orange line) appears offset when overlaid on the raster. I have checked ...
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0answers
42 views

reprojecting (unprojecting) in MrSID decode (SDK)

I am using the C++ SDK (version MrSID_DSDK-9.1.0.4045-win32-vc9). I'm trying to read in arbitrary .sid files and extract rectangular sections of them that can be displayed on top of a "web mercator" ...
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1answer
10 views

Why my map just grayscale mode after use MRT?

i just follow the step to change .hdf file to geotiff file from this site http://duncanjg.wordpress.com/2012/12/11/loading-modis-ndvi-time-series-into-postgis-raster/#comment-1214 and i use data from ...
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0answers
27 views

Can I get Geoserver to return a WMS in gnomonic projection?

I need to be able to pass in the center lat and long. I have tried using the AUTO Namespace for SRS (which works) but this only supports a few projections, the closest being orthographic. I have ...
2
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1answer
83 views

Definitive list of Proj4 supported coordinate systems

I need to determine the minimum set of coordinate systems supported by all tiers of my project's stack. I have a list of EPSG codes supported by Oracle and GeoServer but I'm having trouble finding a ...
2
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3answers
96 views

matching coordinate systems by transforming and projecting

matching coordinate systems of all my data (transforming, projecting) My data uses the GCS_Bessel_1841 coordinate system. Would there be any inaccuracies if i would transform it to DHDN 3-Degree ...
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0answers
40 views

Appropriate reference system for small-scale mapping of the Middle East

I want to create a thematic map of the Middle East that displays certain historic places and regions on a small-scale map (between 1:6.000.0000 and 1:12.000.000). The map has to center the boundary ...
2
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2answers
59 views

Overlaying misaligned DGN file in ArcGIS for Desktop?

I received a DGN file, I believe created in Bentley 8, and there is a bit of a misalignment problem. The dgn, when overlain on a Bing Maps aerial or NAIP image, shows up about 20 m or so off. I'm set ...
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1answer
176 views

OpenLayers 3 drag and drop interaction with custom projection problem

I am trying to add layers by using drag and drop interaction. Here is jsfiddle.http://jsfiddle.net/anuket/umdwzn10/ It almost works, I mean new layer is added, but for Geometry it gives "NaN". Geojson ...
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1answer
35 views

Mapnik tiles have latitude distortion, projection issue?

I'm trying to work out a kink in setting up mapnik-node. My geos are in postgis, and I allllmost have them rendering properly, but my GIS experience is lacking so I can't seem to determine why this ...
2
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0answers
51 views

Mine Grid to UTM

I have been given spatial data (lidar) that was collected in mine grid feet in ASCII format. I am using arc to process but need to define a projection does anyone know how to do this or any other ...
2
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2answers
43 views

Formula for charting a course around the globe, given a location and degree heading?

I'm looking for a formula that takes a long/lat coordinate and a degree heading, (e.g. "I'm standing in San Francisco and I'm facing 45º from north"), and which can draw a line across a map projecting ...
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1answer
125 views

Regional Large Scale Map Projection Choice

I am currently designing a geospatial product that will be primarily used for large and intermediate scales that cover an entire state of the US or more. The UTM projection would be ideal because of ...
4
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3answers
117 views

Geometric Operations in GIS Systems

I have worked with 2D geometry for CAD - My questions are general and relate to understanding operations on geometric entities (lines). Should geometric operations such as line-line intersection be ...
3
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0answers
124 views

Formula for maximum coverage of a geostationary satellite based on earth station elevation

I am trying to create a javascript function to represent the maximum coverage of a geo satellite for different antenna elevations (0 degrees, 5 and 10 degrees) with 3 leaflet polylines. The result is ...
2
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1answer
52 views

Proj4js: Is this correct implementation of Azimuthal Equidistant relative to an arbitrary center?

If I wanted to interpolate points along a Great Circle Arc, it makes sense that either endpoint of the Great Circle is a satisfactory starting place. Next, I suppose I'll need a projection to preserve ...
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1answer
34 views

Transforming Robinson to Equirectangular

I need convert this http://bioval.jrc.ec.europa.eu/products/gam/images/large/access-map.png (is it robinson?) to Equirectangular (ESPG:32662) How can i get this using gdalwarp?
3
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2answers
541 views

Overlaying layers with different projections on Android

Hello, I'm trying to show a map on Android. I'm using two map providers and am having trouble when converting geo point(lat/lon) to point in my viewport(x/y in pixels). 1) the first map provider used ...
4
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2answers
101 views

Is there a command line tool for converting projection in .prj and GeoTiff to EPSG codes?

Is there a command line tool to convert a shapefile projection in the .prj file into corresponding EPSG code? I know that there is website http://prj2epsg.org/search for doing this online, but I ...
0
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1answer
364 views

Equivalence of EPSG:3857 for MapInfo 9.5

I have a raster projected on EPSG:3857 with QGIS. I have image registration in Mapinfo but there is no projection for EPSG:3857. Do you know the projection that I need to use?
0
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1answer
72 views

How to create an interrupted Mollweide map in R?

I am wondering if it is possible to create an interrupted Mollweide map in R. This question is similar to Discontinuous or Interrupted map projections? which does not really have a satisfactory ...
2
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1answer
131 views

Calculating Grid Convergence for Lambert Conformal Conic

What is the formula to calculate Grid Convergence angle (angle between true north and grid north) for Lambert Conformal Conic projection for a given location. Searching online, I have been able to ...
2
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1answer
150 views

Georeferencing a raster using GDAL and Python

I want to georeference a raster using python and GDAL. My current approach is to call gdal_translate and gdalwarp using os.system and an ugly list of ground control points. I'd really like a way to do ...
9
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0answers
234 views

Geotransformation for polar stereographic?

I'm currently working to import CANGRID climate data (provided as Surfer Grid ascii, ".grd" files) into ArcGIS. The grid is 95 rows by 125 columns in size.Metadata provides lat/lon of origin (lower ...
2
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2answers
90 views

Choosing country projections

Anyone know of a good reference (either pay or open-web) that details recommended country projections?
3
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0answers
29 views

Distortion in projected raster

I am having a frustrating problem with something that I think should be very simple. I have a number of DEMs from the National Elevation Dataset (NED), that come standard in the NAD83 coordinate ...
4
votes
2answers
546 views

Is it possible to automatically set CRS of Rasters from PRJ file?

I am trying to learn my colleagues to display measured data (ASCII) in maps relatively easily. I can prepare project, color and symbology style for the point layer and background map. I also found ...
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1answer
62 views

Set default projection of geometry objects in arcpy

I have a script that creates a polyline geometry from scratch using some math to generate coordinate pairs. At the same time, there is a user-defined polygon shapefile that is used to "erase" the ...
2
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0answers
32 views

Project lines onto surface in QGIS

This question may already be answered so please point me in the right direction. I am designing a water distribution system for a rural village in Guatemala. I have created contours for the area. I ...
1
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2answers
546 views

Project WGS84 to Google using MapGuide and WKT

I'm having trouble projecting a simple WGS84 formatted layer over google maps. I can't find a good WKT "API" that not only shows parameters, but explains what each parameter is. The coordinate system ...
1
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2answers
41 views

Correction spatial reference

Please assist me on how to use ArcCatalog to confirm the spatial reference is correct and adjust if necessary.
3
votes
1answer
76 views

How to plot a full hemispheric orthographic projection in R

I want to make a plot like that using R: All I want is the country borders as seen from outer space, no fancy colors needed. It seems I need to use the spTransform function, but it gives me a "non ...
0
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1answer
90 views

calculate distance between points crossing the antimeridian

How can I calculate the distance between two points (lon/lat) if any of the points exceeds the antimeridian (+-180 longitude)? Im using the distVincentyEllipsoid {geosphere} to calculate the shortest ...
1
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0answers
61 views

Clustering the WGS84 point features (projection transformation aspects)

My question is quite trivial and was discussed many times before (like here) but in our case it has the confounding extra requirements... The list of sparsely distributed 2d point features is stored ...
6
votes
2answers
114 views

Why has an orthographic projection been used in this NatGeo map?

I'm wondering why this maps uses an orthographic projection, resulting in 3 maps to view the whole world. What were the requirements or the reasons to choose this projection (why not Mercator ) ? ...
3
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1answer
99 views

Trouble calculating areas in QGIS using field calculator

I am testing various projections to calculate areas using ICES statistical shapefiles and the QGIS field calculator. I am using ICES areas downloadable from the following link: ...
1
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1answer
126 views

Difference between ETRS89 / ETRS-TM32 and ETRS89 / UTM zone 32N

In QGIS I can choose among other things between "ETRS89 / ETRS-TM32" and "ETRS89 / UTM zone 32N". In my test project both projections displayed the layers at the very same place. So, where is the ...
2
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1answer
66 views

QGIS crashing when using 'save as' to save a new projection

Every time I try to save a layer with a new projection using 'save as' my QGIS crashes. The new files are there but they seem false. Please see two screenshots attached, one before and one after I ...
2
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3answers
571 views

Is GeoServer getting coordinate output in GeoJSON WFS wrong?

When I do a WFS request to GeoServer and specify the SRS like this: http://myserver.com/geoserver/wfs? service=wfs& version=2.0.0& request=GetFeature& ...