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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Defining the azimuthal equidistant projection of an Environment Canada weather radar map

Environment Canada helpfully provides recent captures of all national weather radar stations at http://dd.meteo.gc.ca/radar/PRECIPET/GIF/ at ten minute intervals. These are the same GIF images as ...
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1answer
38 views

After how much distance does the x,y coordinate system become noticeably distorted?

I'm working with maritime sensors that give information of moving objects it detects, in azimuth, range and elevation, and we convert it to x,y coordinates for our application to be able to process ...
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2answers
48 views

Projection issues whilst opening shapefile in ArcMap created in QGIS

I created a polygon shapefile in QGIS. Projection was saved as EPSG: 3857, WGS 84 / Pseudo Mercator. When I open this shapefile in ArcMap the projection sets itself as WGS_84_World_Mercator which I ...
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108 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 ...
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3answers
89 views

How to project a layer from WGS84 lat/long (automatic projection) to WGS 84 UTM Zone 23S in QGIS?

So I have a vector layer of polygons in WGS 84 lat/long (i.e. using the automatic projection for lat/long and WGS84 datum). I want to change that to WGS84 UTM 23S in QGIS. I tried doing like online ...
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32 views

Impossible to define the shapefile projection properly [duplicate]

I downloaded some dataset from Hot Export. By default they don't have any projection or coordinate system defined. The only thing I can see is the Feature Extent with values such as: Max Y ...
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1answer
495 views

OpenLayers and custom Proj4 Projection

ok so I'm a newbee in using OpenLayers. I try to map some planetary data on my webMap server using OpenLayers. I defined a proj4 projection as follow: Proj4js.defs["MYDATUM"] = "+proj=longlat ...
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2answers
254 views

projection conversion from mercator to google maps format

Is this spTransform(Finland3, CRS("+proj=longlat +ellps=WGS84 +no_defs+ellps=WGS84 +towgs84=0,0,0 ")) the right way to project a shapefile with this projection coord. ref. : +proj=merc +lon_0=0 ...
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1answer
31 views

Projection For Measuring Distances

Is it the case that when I use Arc GIS to compute nearest distance from a point to a poly-line/polygon, I need to project them both in an equidistant projection? Note: I am using the near tool. What ...
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1answer
961 views

How to define Winkel Tripel in proj 4.8.0?

I have QGIS with proj 4.8.0 installed. I'd like to add Winkel Tripel projection which seems to be defined as +proj=wintri But that definition string does not work. Is this a bug in my proj version, ...
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1answer
559 views

Determining Natural Origin for a GeoTIFF file (Lambert Conic)

I am trying to display an existing GeoTIFF file (from the FAA WAC set) in an application that requires the GeoTIFF NaturalOriginLongitude tag (FalconView 5.1.1). There are some older files in that set ...
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1answer
511 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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1answer
25 views

Polyconic Projection for China?

I have a set of locations/points and I am trying to compute the nearest distance of these points from a Polyline. The points and the polyline lie in China and the Geographic Coordinate System is WGS ...
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1answer
432 views

help with TMS (gdal2tiles) Openlayers 3 and custom projection

I work with a local italian projection (EPSG:3003 Monte Mario Italy zone 1) and I had loaded this projection in my project for evitate to reproject all of my data. I had created the tile pyramid with ...
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7 views

Problem with the DSID Data Set Identification

In my s57 file, I need to set the extent of the mapcanvas, for that i use : mpMapCanvas->setExtent(mpS57->mMapplay.value(DSID)->extent()); but if I display the value of the extents xmin, ...
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1answer
36 views

How to get correct lengths when switching from GCS to PCS?

I'm working on ArcMap 10 and need to get the lenghts (in meters) of the segments composing my line feature class. GCS of the line is WGS_1984. Extent of this data should be: Left 11.236520 dd, Right ...
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1answer
51 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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1answer
62 views

Strange effect in gdalwarp output

I am using gdalwarp in python to extract and re-project reflectance bands from MODIS level 1B (MOD021km). An example of the command that I am using is the following: gdalwarp -of GTIFF -tps -t_srs ...
4
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2answers
427 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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6answers
11k views

Why is the 'straight line' path across continent so curved?

This is the result of mapping the straight line path from a point in US to Poland using Distance Measurement Tool. Also, planes from Asia to US would travel almost over North Pole. Why is the path ...
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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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1answer
166 views

Displaying a map in EPSG:26915 projection in open layers 3

My GIS experience is limited to having worked on several Geospatial Humanities projects. That is to say that I still struggle significantly with the technology (and terminology) in getting to my goal. ...
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1answer
43 views

Using CAD data that is not to be projected in ArcMap?

I need to incorporate CAD data into my geodatabase but the usual steps seem to require defining a projection or projecting the data in some way. All of my geodatabase's feature classes are in ...
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1answer
52 views

Extracting *.tif agricultural area from shapefile?

I am attempting to extract from an image using Esri shapefile that is in the zip file RR_KZKD2012 In ArcGis the spatial reference is Projected Coordinate System: WGS_1984_UTM_Zone_43N. Then am using ...
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2answers
640 views

OpenLayers WMS - TypeError: this.resolutions is undefined

I'm trying to setup a map with WMS and WFS Layers by using Geoserver. However, when I'm combining WFS and WMS (with some Google basemaps) together in one map I got following error in Firebug: ...
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7answers
669 views

Where can I find GIS data to test GIS coordinate operations?

I am trying to find some data that can be used to test GIS coordinate operations from one CRS to another CRS. So far all I have found is the Gold Data set and also various example points in the EPSG ...
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1answer
229 views

GDAL - projection from pixels to geo coordinates

I am using GDAL library in C++. On my dataset, I have obtained geo transform with GetGeoTransform to GT array (GCP is NULL). Than I use this values for this equation (Source): Xgeo = GT(0) + ...
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50 views

Feature Points Shapefile missing Spatial Reference Information

I'm working with ArcMap 10 and I have a feature points shapefile from the Florence (Italy) municipality open data (http://opendata.comune.fi.it/statistica_territorio/dataset_0040.html). Each point is ...
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1answer
62 views

What projection to use for many parts of the world

I'm creating a poster which has many separate maps (rivers of the world). I'd like to use a similar projection for each of them, so they're comparable in terms of shape and size. I guess I want some ...
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1answer
40 views

Postgis geometry column with different srid

I have a table that has geometry column named the_geom. I set SRID value to 29903. And I used Openlayers api to view data on map. I set map srid as 29903 and works well. But if I need to show my data ...
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27 views

How to access Leaflet EPSG:3857 coordinates?

I read everywhere that Leaflet is internally using a spherical web mercator (EPSG:3857), but whatever I try I get either Lat/Lon (EPSG:4326) or strange coordinates I dont understand: ...
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1answer
504 views

WFS request with CQL_Filter projection

I have a layer in Geoserver called bln_blocks. The layer is in EPSG:3857. I am doing the follwoing WFS request with a CQL Filter: var geoserverURL = geoserverURL + '/ows?'; var service = ...
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1answer
52 views

Working with lidar points (LAS To Multipoint) in ArcGIS for Desktop?

Currently I'm working with the LAS format and want to transform from WGS84 to RSO Kertau Malaysia. I'm using ArcGIS-Las to Multipoint and Data Management Tool-Project and succeeded in the ...
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18 views

NetCDF4 Files: Missing Projection & Varying Dimensions (Multiple Files)

All, I hope you can shed some light on issues I've been having regarding NCEP Reanalysis-I netCDF-4 file format: First issue, Projection information is not stored on the downloads I obtained from ...
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1answer
59 views

Layers with the same CRS in QGIS do not line up

I am busy with a project where I have to layer a .dxf and a .kml file but the layers are not lining up. The .dxf file's coordinates are completely wrong and the scale also does not appear to math up ...
2
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0answers
31 views

Aligning Points in Decimal Degrees

Running ArcMap 10.3 I am displaying a layer of manholes from a table coming from SQL. The XYs are in decimal degrees however they are displaying no where near my other layers (NYC PLUTO). I have ...
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1answer
195 views

How to reproject from Clarke_1880_RGS_Lambert_Conformal_Conic to ETRS_1989_LAEA?

I am unable to reproject Marseille shapefiles from Clarke 1880 RGS_Lambert_Conformal_Conic to ETRS_1989_LAEA. I know that Clarke is a geographic coordinate system and it has no datum. I have tried ...
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2answers
250 views

Tiled raster image to be placed in an OSM/ Leaflet.js map

I have a mapoverlay in a custom projection which I need to add as a layer to an Openstreet map within a website. Since I was not able to change the projection earlier, I decided to manipulate the ...
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2answers
892 views

GDAL/proj4 equirectangular projection coordinate system units assumed by OGRSpatialReference and GDALDataset::GetGeoTransform()?

How do I configure my OGRSpatialReference object to specify an equirectangular projection system http://en.wikipedia.org/wiki/Equirectangular_projection where the affine geo-transform matrix (provided ...
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0answers
14 views

Vector data getting misaligned in final print in QGIS [duplicate]

My printcomposer view shows the data correctly aligned with background OSM/Google/Bing data but the final print makes it all misaligned. Data is in 3857 What can I do?
3
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0answers
75 views

Which projection can I use to see alignments on great circles?

I want to put on a QGIS map some historical sites to check if they are aligned. If an alignement exists, the points should stay on a great circle (is this correct?). I want to visually verify this ...
2
votes
2answers
384 views

Calculating surface using Lambert correction?

i'm using lambert conformal conic , so we have distortions along any given parallel , i would like to get the area used to solve this distortion. I have calculated the area using Shoelace formula , ...
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0answers
23 views

ArcGIS: Projection of State Plane Data to a Web Service?

This maybe a naive question but I can't help any online help so far. So we have some data in Shape files. The data is in NAD_1983_StatePlane_South_Carolina_FIPS_3900_Feet WKID: 102733 Authority: ...
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1answer
41 views

What is/are the coordinate systems used in South Africa?

What are the principal datums and projections used in South Africa including the names of geodetic datums and their projections?
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1answer
153 views

Trying to set NAD 1983 EPSG 102631 in QGIS

I was able to find the right coordinate system online NAD 1983 Alaska But now I don't know what to do. I can't find the coordinate system on QGIS. When I choose the one I think is correct it warps ...
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1answer
35 views

Projected MODIS data not aligning with ESRI basemap in ArcGIS for Desktop?

I can not get 1km MODIS data aligned with ESRI basemaps in ArcGIS 10.2.2 for Desktop. See the photo below. I reprojected MODIS17A3 data using the MRT (MODIS reprojection tool). I selected WGS84 ...
4
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2answers
80 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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1answer
42 views

GeoJSON and OSM layers with different projection

I have a GeoJSON from NaturalEarth for world state boundaries and I want to display it with only without backgroung. But also, I want to add a OSM layer as another baselayer option. The code I am ...
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0answers
26 views

Projections way off on data imported into QGIS?

I have elevation data as a .shp from the USDA ARS and Hi-Res Orthoimages (Mystery Projection (UTM 15N?)) from the USGS website as geoTIFFs (plain NAD 83). I am trying to project all of the images ...
6
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2answers
658 views

Using Python, Batch Project output won't drop into feature dataset?

When attempting to batch project in ArcGIS 9.3 or 10 (using either arcpy or arcgisscripting), I cannot get my geoprocessing results to drop into the feature dataset that I specify. The results ...