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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Does a projection's WKT reflect the computer's locale?

This should be quick - we're trying to determine if there are problems parsing some WKT text because the system locale considers the decimal separator to be a comma instead of a period. Anyone know? ...
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2answers
10k views

Arcmap 10 feature with undefined coordinate system projects incorrectly when projecton is defined

I'm fairly new to GIS, and am slowly feeling my way through ArcMap 10. I have run across a problem defining the Geographic Coordinate System and projection for a feature (the feature currently has an ...
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1answer
635 views

How to convert WGS84 to UTM when the study area covers 4 UTM Zones: 43- 46?

I'm working in ARCGIS 10.2, my area of interest falls in 4 UTM zones 43,44,45,46 equally distributed so i can't use the option of majority of area's UTM zone. Since i need to carryout varies analysis ...
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2answers
6k 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 ...
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251 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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588 views

Is there any Google Maps-like zoomable world map, but with an equal-area projection?

Whenever I look at Google Maps at a global or polar area, the projection hurts. Is there any web service with a zoomable world map, that uses an equal-area projection — preferably pseudorectangular ...
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2answers
153 views

Why is it not advisable to perform spatial analysis on layers with source datasets having same datum but different projections?

I have read that it is not advisable to perform spatial analysis on two layers with source datasets having the same datum but different projections loaded in ArcMap. Since the second layer should ...
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4answers
719 views

Determine Projection

I was given a shapefile at work with the information that it is in Lambert Azimuth Equal Area (LAEA) projection (EPSG 9820). After some research on the web, I found out that EPSG 9820 is a generic ...
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1answer
1k views

Matching ArcGIS and QGIS coordinate systems

I have the following info for a feature class in ArcGIS that is supposed to be in WGS 1984/UTM 16N projected coordinate system: Projection: Transverse_Mercator False_Easting: 500000.000000 ...
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4answers
152 views

Get a coordinate system from raster file

I am writing a code to loop through all the files in a folder and reproject them, using a raster as the spatial reference. I have a suspicion that there is a different way to get the coordinate system ...
4
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1answer
264 views

Equal area projections with different area results in ArcGIS for Desktop?

Using ArcGIS, I have to calculate areas of huge polygons all over the Pacific Oceans betwwen 20N and 30S. I have been trying different Equal-areas projections (Cylindrical and sinusoidal for example) ...
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3answers
383 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 ...
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2k views

Problem with Geometry SRID in PostGIS

I ceated my table (borne) in PostGIS id_borne serial NOT NULL, num_borne character varying, shape_borne geometry I successfully changed the SRID of my table using select ...
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4answers
130 views

How do I create a map that is not to scale in QGIS?

I want to make a map that isn't to scale and I'm so used to being pedantic about CRS and scale that I don't know where to start. The map that I need to make is a simple guide for people to get to a ...
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1answer
470 views

D3 to match this QGIS projection?

I have a map of Finland in QGIS, which says CRS = ETRS89 / ETRS-TM35 (Authority ID = EPSG:3047). I'm trying to show the map with D3, and can't quite match the borders/projection. The black one is ...
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2answers
3k views

German coordinate system from Lat/Long

I have WGS latitude and longitude for data points near Munich and I'd like to use a grid-type coordinate system, like the Ordnance Survey grids in Ireland or the UK. What coordinate system do you ...
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1answer
4k views

Change vector projection in Openlayers

I have added vector layer to map: vactorTest = new OpenLayers.Layer.Vector("Editable Features", { strategies: [new OpenLayers.Strategy.BBOX(), saveStrategy], projection: new ...
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4answers
14k views

Getting shapefile in right projection using ArcGIS Desktop? [duplicate]

I have an older map that I didn't create. I'm just trying to get everything to line up on it, and having a hard time. The data frame is in NAD_1927_UTM_Zone_12N, as are the point shapefiles (derived ...
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2answers
305 views

Map projection process for three-dimensional point cloud

I have some points given in ECEF coordinates (or LatLongAltitude based on WGS84, which is interchangable in my understanding). Currently I am working on a mapping software which allows to visualize ...
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2answers
560 views

Projected coordinate system for South America

Does anybody have any suggestions for a projected coordinate system for the Northern part of South America? I have a data set that reaches from Venezuela to Southern Peru and I'd like to do some ...
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4answers
9k 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 ...
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2answers
168 views

How to translate WIGeoEU projection from ArcGIS to Qgis?

I have a Layer with this projection in ArcGIS: ...
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2k views

Cartesian world sized projection WKT/EPSG code?

I am after the EPSG code or Well Known Text (WKT) of a projection that puts the centre of the earth a 0,0,0 and each point is a cartesian XYZ distance from that. My existing data is in WGS84 ...
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3answers
2k views

Is NAD 83 the same as EPSG:4326?

I'm getting mixed messages about these projections. For example -Is this projection below, NAD 83, 4326? GEOGCS["GCS_North_American_1983",DATUM["D_North_American_1983", ...
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3answers
7k 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
2k views

How to “calculate” distance-to-ground of all 18 OSM zoom levels?

Assuming I'm building a 3D solution with the "world" being mapped to global geo-data supplied by OSM / Cloudmade... think http://www.webglearth.com but with completely different goals and use-cases. ...
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1answer
495 views

No difference between distances measured in projected and non-projected data

I'm performing measurements of distances in Km between a lot of localities by using the "Point Distance" in ArcGis 9.3. I realized that the results obtained after using projected coordinate system are ...
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1answer
306 views

Is a WMS map always a constant scale?

If I get a map back from a WMS server is the scale always constant over them map regardless of the reference system? So if I have a map which is 100 pixels wide, will the point at 50 pixels always ...
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3answers
4k views

Parameters for ED50 -> ETRS89/WGS84 seven-parameter transformation which are good for Denmark?

I am looking for parameters for a seven-parameter transformation (Rx, Ry, Rz, Tx, Ty, Tz, s) from ED50 UTM (zone 32U) to ETRS89 and/or WGS84. The best match I could find is here: ...
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5answers
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How to re-project coordinates in a gml on-the-fly in Geoserver?

I am using Geoserver to get featureinfo, but sometimes I want to re-project the native SRS in the output gml. The request is a (WMS) "GetFeatureInfo" with INFO_FORMAT: application/vnd.ogc.gml. I am ...
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1answer
60 views

Why can't QGIS handle the Kavrayskiy7 projection although it is supported in proj4?

I'd like to make a world map using the Kravayskiy7, however QGIS seems to be unable to handle the projection, even though it is supported by proj4. 704900 (as is the EPSG for kav7) is not listed in ...
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71 views

What projection should I georeference this historical map to?

I'm using ArcGIS. I have a historical map from 1884. It has bathymetry information which I would like to compare to modern bathymetry models with as much accuracy as possible. I don't know what ...
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287 views

Proper ground-to-grid correction and projection from old survey maps

I asked this question over on the ESRI geonet site, but haven't had any luck there, sorry for the duplication... I'm working on digitizing a group of maps from the 1950's that show locations of ...
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2answers
246 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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2answers
3k views

QPJ files on ESRI software

We have some GIS data, which was converted from AutoCAD dwg to TAB using mapinfo, then converted to shapefiles as that's what we are required to create. Editing the data fields was done in the shape ...
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2answers
627 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 ...
4
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2answers
6k 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 --> ...
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2answers
799 views

Looking for formula for the Robinson projection

I'm looking for a source that describes how the Robinson projection is calculated. I'm going to use this for converting long/lat into Robinson coordinates in both R and in javascript.
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1answer
208 views

Choosing Projection for Gulf coast region of USA?

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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2answers
447 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. ...
4
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2answers
548 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
38 views

Importing ESRI:102091 Monte Mario reference system

I am trying to import a dataset generated by my local council (Turin, Italy). The data appears on the map but it's slightly shifted and it doesn't match the Open Street map layer that CartoDB uses ...
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1answer
78 views

How to center a user-defined CRS on an area of interest?

My study extent in central Iran straddles two UTM zones (39 and 40): I would like to create a user-defined CRS in Transverse Mercator projection with central meridian inside this area. Through ...
4
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2answers
146 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 ...
4
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1answer
187 views

How to bulk import ESRI projections into Postgis

Where can I get a file that would allow me to bulk upload all of the ESRI projections into the spatial_ref_sys table of postgis. I know that you can get insert statements on spatialreference.org; ...
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1answer
320 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
186 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 ...
4
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2answers
543 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
160 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
1k views

What is wrong with this Proj4 transformation?

I'm implementing support for WMS maps in my company's software. Servers return a list of projections their maps are available in, but our software only displays data in WGS84 (lat/lon or UTM), and ...