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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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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45 views

How to store lat/long in PostGIS database?

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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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 ...
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32 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 ...
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20 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 ...
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26 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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18 views

OpenStreetMap with OL3 and EPSG:3301 projection

Trying to add OSM layer to my map, as Tile layer or as WMS layer, but for Tile layer it is appearing in different projection, and for WMS layer there are error Resource interpreted as Image but ...
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3answers
36 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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1answer
24 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 ...
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23 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 ...
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2answers
34 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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2answers
26 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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29 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 ...
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3answers
78 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 ...
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1answer
22 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
21 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?
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2answers
67 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 ...
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1answer
84 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 ...
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1answer
23 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 ...
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2answers
77 views

Choosing country projections

Anyone know of a good reference (either pay or open-web) that details recommended country projections?
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0answers
18 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 ...
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1answer
69 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 ...
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24 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 ...
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1answer
37 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 ...
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31 views

Correction spatial reference

Please assist me on how to use ArcCatalog to confirm the spatial reference is correct and adjust if necessary.
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1answer
32 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 ...
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151 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 ...
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34 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 ...
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1answer
48 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 ...
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1answer
37 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 ...
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1answer
65 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: ...
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1answer
48 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 ...
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Is there a standard for the specification of .prj files?

We use shape files for data exchange. I've looked at the .prj files: different programs produce different prj files. Is there a standard how the parameters must be specified in a prj file? AFAIK the ...
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32 views

Problem with projection of Slovenian Shapefile in QGIS

I hope someone can help me for this: I'm doing my masters thesis in Slovenia (in the field of wildlife management), for this I got a Shapefile of slovenian data by the University. As a main layer, I ...
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1answer
54 views

Proper projected coordinate system for Minnesota for measuring areas

I have seen in ArcGIS many different State Plane systems for Minnesota (location coordinates in WGS84: 44,07 lat/-94,61 long) within the Projected Coordinate system group: NAD 1983 (CORS 96) ...
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23 views

Pros and Cons of a latitude adjustment grid vs other methods of area calculations

When working with high resolution global raster data in WGS 1984 I often need to calculate areas. Now the traditional way for me to achieve this has been to reproject the data to an equal area ...
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18 views

How can one use Google Maps API to mimic QGIS projection/CRS

I used QGIS to find the extents of a list of features. However, the resulting data auto-generates the CRS and changes it from WSG84 to a custom one. Is there a way to use the autogenerated CRS in ...
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1answer
19 views

Difference between source SRS and target SRS in Raster Warp function

Hello I am trying to change a raster layer projections from WGS84 to a custom Lambert layer using 'Raster' --> 'Projections' --> 'Warp' function. I have been asked for source SRS and get SRS. what is ...
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1answer
45 views

How can I reproject a layer in a spatialite database

I'm writing an android mobile application and, for performance reasons, I want to reproject my layers to match the basemap's projection. Is there a command to do that?
2
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2answers
33 views

Custom projection problem with proj.4

I have some vector files that come without projection. So I have to define my own projection in QGIS. The information that comes with the data reads as following: Projection: Lambert Azimuthal Units: ...
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25 views

Precision loss when transforming coordinates systems in GDAL (vector layers)

Anybody knows the order of magnitude of the error introduced when transforming coordinates using GDAL? More specifically, I would like to know if significant error is introduced when the ...
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1answer
26 views

ArcMap Area Calculations vs MultiNet FEATAREA Field Discrepancy

I'm finding a huge discrepancy between the values supplied in the FEATAREA field in my MultiNet data and the area calculation results from ArcMap v10.2.2. In this case, I'm looking at the area of ...
2
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1answer
105 views

openlayers display projection

I'm displaying coordinates in epsg:900913 using ol.control.MousePosition() with OSM. I'd like to convert these on the fly in another epsg:2154. I call in the header : <script ...
3
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1answer
51 views

Is the bilinear resampling technique appropriate for the projection of ASTER data?

I need to project some ASTER data from a geographic coordinate system to a projected one. I have read online that the cubic resampling technique is the most appropriate for this purpose. However, ...
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93 views

Transforming between epsg:3857 and Google Maps Tile coordinates

Hio, I used to use a simple python project (https://github.com/hrldcpr/mercator.py) to convert between wgs84 and google maps tile coordinates. This project doesn't have a license, and looks like it ...
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19 views

Guessing a map projection by its values [duplicate]

This is more a theoretical question and not an actual problem that I have. Is it possible to identify or classify projections by their numerical coordinates? Or alternatively rule out in some sort of ...
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19 views

Projecting Data with Transformations - Alignment Issue

Problem: I am having problems getting data to align properly with basemaps layers. The image below shows the difference between roads. The centerlines shapefile's coordinate system is ...
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20 views

How to get ASTER level 1B data to overlay correctly on google earth/ bing maps/ arcmap imagery basemap

I have recently purchased Two granules of ASTER 1B data from ERSDAC. Upon importing this data into arcmap 10.2, the layers representing each band were specified as being projected in: ...
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1answer
38 views

How to import and project ASTER 1B data into Arcmap?

I recently purchased a granule of ASTER 1B data from ERSDAC, when I import any of the associated rasters into ArcGIS, the image is displayed as being only 1m across, when the actual area represented ...
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1answer
26 views

Short list of .prj options in .pyt

I'm tasked with creating a .pyt to distribute across our office and field computers (state geological survey) for converting .gpx to features but constraining the choice of projections/datums to seven ...