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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154 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
577 views

Why is tiff different in epsg 3857 and epsg 900913 in gdal

When I transform tiff from 4326 to 3857 and from 4326 to 900913 in gdal, I get different result(when display in Qgis) eventhough these two projections(3857 and 900913) should be the same. What is ...
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2answers
531 views

Setting coordinate systems in gvSIG: Is the workflow similar to QGIS?

I am still learning how to use coordinate systems and projections, but I hope this basic question will be easy to answer. My goal is to be able to use either QGIS or gvSIG to create a simple county ...
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2answers
4k views

Error 000735: Input Dataset or Feature Class: Value is required

I am a true novice when it comes to ArcGIS and computer programs like this one. Am taking a class and cannot get the Project function to work under the tool box. The path I used was ArcTool box --> ...
4
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2answers
365 views

Reproject TM65 to OSGB in ArcGIS

I have a TIFF file in the TM65 (Transverse Mercator) projection, and want to convert it to the OSGB (British National Grid) projection. I'm trying to do this in ArcGIS using the Project Raster tool. ...
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3answers
6k views

How do I include proj4js in openlayers?

in my Openlayers app, since the base map projection is not epsg900913 or 4326, I need to include proj4js in order to use geolocation feature. but i got such a error notice: GET ...
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2answers
429 views

what are the main advantages of using a Double Stereo projection?

I'm not per say a GIS guru, I'm more of a user of the technology. On a recent project we were asked to analyze, provide, and submit all our analysis using a Double Stereo projection. What are the main ...
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1answer
55 views

Is there a difference in results between Simplifying a geometry by different projections?

We have geometries in a PostGIS database projected in srid 4326. We need to have these geometries simplified with ST_SimplifyPreserveTopology. My question is whether this geometry needs to be ...
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2answers
300 views

Why is the Google Maps circle shape not matching to the distance calculated with PostgreSQL?

I am running a PostgreSQL 9.1 Database with PostGIS 1.5 extension. Several coordinates are stored in there with type GEOMETRY (SRID 4326). I'm building a web-application with Google Maps Javascript ...
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2answers
108 views

towgs Definition for European Datum 1950

I am new to all things GIS so apologies for a basic questions. I am trying to specify the CRS of a climatic raster layer in R. It is an equal area projection based on Europe Equidistant Conic and the ...
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1answer
248 views

Error in Min. Bounding Geometry results

I'm getting consistent, weird results from using Minimum Bounding Geometry to make circle polygons. I'm not sure if a datum issue, but I'm leaning more towards something wrong with Minimum Bounding ...
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1answer
157 views

Global projection with zero scale distortion at non-zero latitude

I am looking for a global projection with zero scale distortion at non-zero latitude. I have tried using an Oblique Mercator projection centred at a specific latitude and longitude of centre (with ...
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2answers
419 views

How do I Capture GDAL projection and create matching output (OGR or GDAL) shape files?

Working in C++, using GDAL and OGR: Depending on what the user has supplied for image input, I need to output point (or other) shape files in the same projection as the input raster images. The ...
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2answers
154 views

GIS projection for non-geographic data

I am working on two different types of data. One is related to mapping of Genome structure and another is creating a layout of the inventories inside Internet Data Center. What I am confused about is ...
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1answer
158 views

What is the most appropriate Projection for the Gulf coast region?

What are the most appropriate datum and projection I could use for the Gulf coast region - spanning Louisiana, Mississippi, Alabama, and Florida? I have to analyze block group data along the coast. ...
4
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1answer
705 views

Openlayers and Geoserver fail to reproject while editing Vector with WFS-T

I can't get the Openlayers and Geoserver work with WFS-T editing a vector layer. I have a layer of points where the Native SRS is EPSG:32639. After trying a lot of combinations, I ended up with two ...
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2answers
1k views

TileCache and Openlayers Problem - Projections?

I have a very known problem, but I can't solve it. I have set the same maxExtents in the config as in the Openlayers init JS. I have done the same thing with the projection (EPSG:900913) and done all ...
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1answer
241 views

Access is Denied error on ProjectEx call

I need to be able to convert a lat/long coordinate into a point coordinate and am having trouble getting my code to work. I created a test app isloating the code that is giving me problems. I'm ...
4
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2answers
1k views

Projected maps don't overlap

I am very new to arcGIS and so apologise if this is a really simple question, but it has had me (and what I can find on the internet beat for 2 days now. I am trying to build a series of layers of ...
4
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2answers
65 views

Qgis - Projection Problem with EPSG:2272

I work in both Qgis and ArcGIS. Most of my data has been created using ArcGIS and all of my data should be in the EPSG:2272. When I add my data to Qgis, it does not recognize my projection and gives ...
4
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1answer
250 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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1answer
248 views

How to rotate sphere when using Vertical Near Side Perspective projection?

Situation Data is currently displayed on a globe using the Vertical Near Side Perspective projection with a blue circle as a backdrop. Problem I would like to 'rotate' the globe by altering the ...
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1answer
444 views

PostGIS spatial reference ID (SRID) for regular cartesian coordinate system?

I would like to store a polygon as a set of 2D points represented as x, y coordinates of a Cartesian coordinate system. Which spatial reference can I use? Looking at my spatial_ref_sys table, all the ...
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1answer
324 views

What's the difference between Geographic coordinate system 4019 and 4121?

I have a DEM with cell size 100,100 with geographic coordinate system GRS_1980_Transverse_Mercator, Datum: D_GRS_1980. I created some extra shapefiles with projected coordinate system: Greek_grid, ...
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2answers
1k views

Create custom projection using either QGIS (or ArcGIS Desktop)?

I have searched for an answer to this but don't see anything relating to what I am trying to do. What I have are a series of Geographic Coordinates, Latitude, Longitude, Ellipsoid heights. What I ...
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1answer
401 views

How to convert a png with known bounds from Plate Carree to Mercator with GDAL

I have a png image that shows the region defined by the geo bounds UpperLat, LeftLon, BottomLat, RightLon (in degrees & -ve for West Lon and South Lat) in Plate Carree EPSG:4326. I want to convert ...
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2answers
656 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
269 views

Using projections to obtain perspective views

I understand that a perspective view is essentially a type of projection. Is it possible to create projection definitions for a typical GIS system that will mimic a perspective view from a particular ...
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1answer
92 views

How to use SRTM Global DEM for Aspect calculation?

I need to derive a raster representing aspect for North America (from STRM data, originally in geographic lat/long). In most projections, true north is only map north along eg the central meridian so ...
4
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1answer
254 views

What's the correct way to reproject a population raster?

I'm working with a population raster that is in the WGS84 coordinate system, and I want to get it into a projected coordinate system (Albers Equal Area), using ArcGIS 10.1. According to the metadata, ...
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2answers
3k views

How to convert a NetCDF file to GeoTIFF using GDAL

I have a NetCDF file which contains data for the number of rain days in the UK. I'd like to convert it to a GeoTIFF, but can't get GDAL correctly georeference it. See dumps from gdalinfo below. I ...
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1answer
97 views

How to select projection

I have to compare geometries anywhere in the world; mainly between 65N and 40S but also in the Arctic latitudes. I need "commercial accuracy" - not military or navigational. For example does a line ...
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1answer
2k views

R - Plotting shapefile with geographical (raster) data

Over the last few days I have been trying to plot a shapefile over data loaded into a data.frame within R. It should be a view of radar precipitation with an overlay of the country borders from a ...
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1answer
1k views

OpenLayers Map with custom SRS (without EPSG code) [closed]

Is it possible to show geodata by OpenLayers in custom projection? I want to show my geodata in OpenLayers interface. Source layer(s): shape-file(s), standard epsg:4326 lon/lat projection; ...
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2answers
575 views

Why isn't valid geometry not valid in NetTopologySuite when close to poles?

I have a Polygon which crosses the south pole: Polygon in WKT: POLYGON((5.86826073458095 75.6638564054071,-16.5436836399021 63.2220742891438,-19.3664667294083 59.846221066959,-21.7009816876343 ...
4
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1answer
1k views

How to use DotSpatial to project/reproject shapefiles on the fly

I would like to use DotSpatial to reproject shapefiles on the fly before loading them to GeoServer. I've been looking for tutorials on how to get started with this in vain. Any pointers on where I can ...
4
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1answer
2k views

Distances in {Plate Carrée projection - EPSG:4326 - WGS84}

So, "4326 is just the EPSG identifier of WGS84" [3], indeed http://spatialreference.org/ref/epsg/4326/html/ says it is a GEOGraphic Coordinate System: GEOGCS["WGS 84", DATUM["WGS_1984", ...
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1answer
313 views

Projecting gps data to get length of resulting line shape in ArcMap 10.0

I have gps data in WGS84 geographic coordinates. I will use the gps data to build a line shape in ArcMap 10.0. The data falls in UTM 15N. To get most accurate length of line, should I project the ...
4
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0answers
115 views

Is there a locally consistent projection for anywhere in the world?

Is there any projection that I can use that gives me easting northing values that are locally consistent? By locally consistent I mean: For any pair of objects inside a square with 5km side; if I ...
4
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0answers
32 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 ...
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votes
3answers
6k views

Which CRS to use for Google Maps?

I am trying to map a Shapefile (download) onto a Google Map using the Javascript API. The Shapefile describes the boundaries of NYC School Districts. The file's projection was Lambert Conformal ...
3
votes
2answers
248 views

What projection is this in GDAL classification

I need to re-project a PNG from a given projection to the Google maps projection. I have a grid of the source projection, looks like a Mercator projection. What is the exact name of this projection in ...
3
votes
2answers
4k views

Meridian convergence. True north, magnetic north and grid north

I'm having difficulty wrapping my mind around meridian convergence, the horizontal angular distance between true north and grid north. Say I want to determine if a feature lies to the east or west ...
3
votes
3answers
438 views

Which projection is best for mapping the contiguous United States?

If I wanted to project latitude & longitude data for the contiguous United States (the United States excluding Alaska and Hawaii), which projection would I use? I prefer more accurate distances ...
3
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3answers
268 views

Which equal-area projection to use for UK?

I have a bunch of UK polygons that are saved in my PostGIS database as WGS84 projection. I would like to calculate the area of these polygons using st_area. According to this answer I can save these ...
3
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3answers
2k views

How to transform data points from WGS84 to NAD27?

Preface: I have a set of lat and long data points from Google Maps, which I believe are in WGS84. My project data is in NAD27(BLM14). These points are in West Texas, where NAD27 differs from WGS84 by ...
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1answer
146 views

Problem with projection in layer

I'm having problems with visualizing a layer which is in EPSG:4326 Apparently the geometry looks perfect, but I don't know why, it's not in real coordinates. I have projected it to 4326 with QGIS, ...
3
votes
2answers
5k 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 ...
3
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3answers
350 views

How to reproject to other projections than WGS84 or Webmercator?

I have an OpenLayers map with a vector layer to add points on. I'm using Google Maps as the base layer. After the point is added, I need to store the data in my database as lat/long and x/y. Can I ...
3
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1answer
426 views

How would I go about re-projecting the Blue Marble raster maps into a robinson projection using free tools?

I would like to convert the NASA Blue Marble maps into a robinson projection.