Questions tagged [mercator]

The Mercator projection is a cylindrical map projection presented by the Flemish geographer and cartographer Gerardus Mercator in 1569.

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Generate EPSG:4326 Vector Tiles

My goal is to create EPSG:4326 vector tiles (using Plate Caree) that can be served in Leaflet. I currently have a .shp file, which I converted to a geojson file using ogr2ogr. The main obstacle to ...
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73 views

Regular grid for whole planet

I`m trying to generate rectangular grid for whole world with fixed cell size in 350 meters (width and height are equals). What i tried to do: 1) in main loop iterate trough longitude in range [-180; ...
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GPS coord to SVG coords

I am trying to make an interrative map using SVG and I need to implement a coordinates system. So I look at http://jsfiddle.net/an3BZ/145/ but I do not know how did he calculated those nortLat ,...
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Reprojecting xy tiles from mercator to Gauß-Krueger in ubuntu terminal?

I have exported a map from tilemill as mbtiles and converted them to xyz tiles with help of mbutil. The tiles should be used (for learning purpose) with mod_tile or GeoServer and displayed in ...
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1answer
2k views

Converting mercator meters without UTM zone?

I've been attempting to extract track information from Humminbird (Side Imaging Sonar) binary files and have hit a stumbling block with the coordinates it provides. The values are apparently in ...
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586 views

Improving accuracy of mercator meters conversion to lat/lon?

My question is an extention to Converting mercator meters without UTM zone? While the answer in the previous Q&A got me so far, I've now come to an impass. While the conversion I do from Mercator ...
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1answer
106 views

Converting X and Y coordinates from Mercator world map (square) image to Latitude and Longitude

I'm using the following JS to transform Latitude and Longitude to X and Y coordinates but now I need the contrary, transforming Latitude and Longitude to X and Y. export const latLon2xy = (lat, lon, ...
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18 views

proj: Oblique Mercator specifying two points on central line

I'm trying to use Oblique Mercator in QGIS 3.4, which uses proj to calculate coordinates conversion. I specify two points in the central line, rather than specifying the center and alpha. Oblique ...
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1k views

Transforming lat and long to Mercator x and y

I've been trying to plot a set of lat and long coordinates to a Mercator map using the following set of equations: x = long - long0 y = ln(tan(pi/4 + lat/2)) These equations are from a page on ...
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4k views

Calculating Mercator coordinates from lat/lon

I am new to GIS but I am working on a project mapping a building using floor plans and JOSM. Using the PicLayer plugin I added the .png floor plan as a layer. I wrote a .cal file to set the scale, ...
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Calculating planar distance based on point coordinate and geodetic distance?

Using ThinkGeo, I have a Lat/Lon coordinate, and a distance of .1 miles. The .1 miles represents the radius of a circle and I'm trying to draw this radius around the lat/lon coordinate. The map units ...
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79 views

Converting between coordinate systems but retain visual shape? [closed]

We have some data that is stored in GeoJSON format (using EPSG:4326), but now we want to display the data in the mapbox-gl-js, which only supports EPSG:3857 for display (support for other projections ...
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Adding additional geometry column in PostGIS?

I'm importing many sets of geodata into PostGIS, and they have different SRID's. (Some have EPSG:3857, some EPSG:4326, some something else). I'd like to create an additional geometry column, eg. ...
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398 views

Using project / layer CRS in QGIS?

I'm using QGIS 3.4.1, and I'm trying to print 61km x 61km area map of somewhere South Korea. Then I need to send this map with west / east latitude and north / south longitude info to other person, ...
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926 views

Mercator map coordinates transformation formula

I have a third-party application with a city map of size 131072x131072. There are data on this map which contains x and y coordinates. I want to transform these coordinates to latitude and ...
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221 views

Calculate Latitude based on a mouse position on Mercator map

I have a similar question to the one found here, Mercator projection: formula for latitude based on pixels? The answer was very helpful but my question is just different enough that it doesn't quite ...
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1answer
279 views

Angular rotation using Proj4, for local coordinate system

I have a polygon feature on map to which I need to transform the coordinates to local coordinate system with respect to new origin while keeping the same datum. So far using the Proj4 library and by ...
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1answer
3k views

Re-projecting from Polar projection to EPSG:4326?

I simply want to project a polar stereographic raster (EPSG:3411) to Mercator (EPSG:3857) or WGS84 (EPSG:4326). The data I is from NOAA. $gdalwarp -s_srs EPSG:3411 -t_srs EPSG:3857 northpsg.20141027 ...
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Map camera image onto sphere

How would I determine what the red point (phi', theta') is for a camera oriented at a known (phi, theta) is from a given image? The point of this is to determine what (dphi, dtheta) is so that I can ...
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41 views

Straight lines plotting as curves

I'm trying to do something really simple, plot a rectangle using psxy on a .cdf grid file. Something like: grdimage grid.cdf -JM20c -R-70/0/20/60 -Bf20g10 -K > image.ps psxy rectangle.dat -JM -R -B -...
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1answer
2k views

Convert lat/lon to Mercator x/y, then measure distance

I'm attempting to convert latitude/longitude coordinates to X/Y coordinates on a 52,000 sq. ft. grid according to a simple Mercator projection. I used the following Python code to accomplish this, ...
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264 views

Flat Map that can go thru North Pole

Is there any map SDK or tool that can show the navigation that passes through the north pole in a flat way? Basically If I use a Mercator projection map it is only flat and cannot show the north part ...
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15k views

Calculating distance scale factor by latitude for Mercator

This was really inconvenient topic to google out - so I'm asking for clarification, did I understood things correctly. I'm talking about measuring short distances in Mercator projection (3857). You ...
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2answers
114 views

Why maps package adding straight lines in North America using mercator projection in r?

Why is this code creating a bunch of lines crossing the map? map(database = "world", proj="mercator", fill=FALSE, bg="white", resolution=0) How can I remove it without changing the ...
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880 views

C# - convert lat long coordinates to WKT format

How can I convert coordinates to WKT format like 39.8251136,-8.3824103 with 900913 system (spherical Mercator)? My client is askying me something like this: SRID=900913;POINT(-939520.0088637 4744291....
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119 views

Mercator - create uniformly distributed dots over map

I have a map in Mercator projection. I know coordinates of corners. I want to render uniformly distributed dots to map. for (float latDeg = startLatDeg; latDeg <= endLatDeg; latDeg += stepLatDeg){ ...
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Problem with parseWKT : projection mercator-2SP

1 -CoordinateReferenceSystem crss = CRS.parseWKT("PROJCS[\"Mercator\",GEOGCS[\"WGS 84\",DATUM[\"WGS_1984\"," + "SPHEROID[\"WGS 84\",6378137,298.257223563,AUTHORITY[\"EPSG\",\"7030\"]]," ...
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2answers
2k views

Using pyproj and Mercator: x_0=0 and y_0=0?

I'm having a hard time figuring out how to project correctly from a Mercator projection to LAT/Lon. Basically, I have a netCDF file with the following variables: LON0 = 42.0 => reference longitude ...
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1answer
1k views

How a draw a circle (on the surface of earth) on a mercator projection?

I would like to use R and leaflet to draw a circle (a real circle on the surface of the earth) on a mercator projection. In the following code, I have the center of the circle (with lng=0 and lat=60),...
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55 views

problem converting OTF from Mercator to equal area

QGIS 1.8.0 on OSX 10.10.5: I've got continent outlines from Natural Earth that are in EPSG:4326 (degrees) plus USGS tree range data in EPSG:2030 (also degrees). When I set the project CRS to EPSG:4326 ...
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325 views

Generating perfect tile set from Mapbox for given zoom level?

I'm using Mapbox API to generate bitmap tiles. First of all I have generated whole world tile with zoom 1 (seems it doesn't matter 0 or 1) and resolution 1280x1280. This tile perfectly positioned from ...
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1answer
747 views

Converting EPSG to D3.js

Given an EPSG projection (say, this Alabama one: http://spatialreference.org/ref/epsg/26729/) How can you take the given WGS84 projection bounds in such a way that you can use them in a D3.js ...
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2answers
11k views

Making geotiff and reprojecting to EPSG:4326 using GDAL?

My goal is to download a gif file from this webpage: http://aviationweather.gov/data/iffdp/2104.gif Then crop it to the known latlon bounds of 75N,45S,35W,70E, convert to geotif, and then project to ...
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227 views

a localised 2D coordinate system from GPS coordinates

I spend a few days reading about coordinate systems, map projections, datums, etc. Since I am new to gis, I am not confident I am doing this right. Problem at hand: I have a GPS device that gives ...
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1answer
303 views

gdal2tiles pixel shift in output tiles

I would like to re-calculate large geotiff files (10,000 x 10,000px) with the help of gdal2tiles into little (256 x 256px) tiles. The process works fine. However, the result is not perfect. There is ...
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1answer
800 views

Formula of mapnik bounding box (spherical mercator)

I want to implement a tile server and I'm following the code in the repo node-mapnik-sample-code. When a request is sent with the parameters x, y, z (longitude, latitude, zoom), those parameters are ...
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1answer
565 views

Convert from WGS84 to 2D projection

I have a map in the form of .bil & .hdr using WGS84. I'd like to convert this into another map using a 2D projection while keeping the lat/long information. What I'd really like with this new map ...
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3k views

What's the accuracy of Web Mercator EPSG:3857?

Are there any references on the accuracy or (min/max/avg) error of Web Mercator when it comes to e.g. distance calculations? For the sake of completeness, I haven't found any reference to the ...
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3answers
7k views

Mercator: scale factor is changed along the meridians as a function of latitude?

"In Mercator projection the scale factor is changed along the meridians as a function of latitude" How to calculate the Mercator scale factor as a function of the latitude in decimal degrees ? I ...
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2k views

How does what3words build a grid of squares on the surface of the Earth?

What3words built a grid of squares of 3m2 on the earth. Does anyone know what is the algorithm ? I started with this method: the range of longitude is [-180, 180] and the range of latitude is [-90,90]...
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QGIS Qtiles from EPSG 3395

I am having issues while converting my layer from 4326 to 3395. My Qtiles does not make tiles. I have a source mapinfo in 4326 with long, lat pairs. My goal is to show this on a maps.yandex (3395 ...
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1answer
283 views

projecting onto Cartographic coordinates using Gauss Conformal Mercator in python

The shapefiles and boundaries I work with are on WGS 84 referenced to SA: GEOGCS["WGS 84", DATUM["World Geodetic System 1984", SPHEROID["WGS 84", 6378137.0, 298.257223563, AUTHORITY["EPSG","7030"]], ...
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1answer
550 views

Fixing mercator coordinates that are outside the world bounding box?

I'm using mercator-projected overlays from a crowdsourced website where volunteers georectify images of maps by hand. Unfortunately, the slippy map that serves as the site's interface wraps and allows ...
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1answer
1k views

How to quickly change EPSG in QGIS (Openlayers; 4326 vs. 3857)

I'm using Qgis 2.12.2-Lyon on Ubuntu 14.04 LTS. With the OpenLayers plugin I added some OpenLayers to my Canvas. I usually use the WGS 84 (EPSG:4326) projection for my project, but I have to switch ...
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780 views

Map scale factor when converting from Mercator to Equirectangular

Lets say I have a map in Mercator projection, and I know top and bottom latitudes: topLatitude = 80; bottomLatitude = -55; I also know width and height of a map: width = 800; height = 500; I want ...
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1answer
3k views

Converting x,y on mercator to WGS84 latitude and longitude

How do I convert a particular point on a Mercator map (points in a Mercator map svg) to WGS84 coordinates? Is it simply a direct translation of the x,y values, using a multiplier which matches the map ...
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595 views

Geoserver Mercator to EPSG:4326

I have external WMS server, which have a layer pusblished in Mercator projection (EPSG:3395). I have this layer set up in Geoserver (2.8.1, GeoTools 14.1). I need to expose this layer via WMTS in ...
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1answer
6k views

How to make a point from real latitude and longitude values

My program has a center point and one moving object . At this moment this point is somewhere in Europe.But Now i have to change that point from the latitude and longitude values(of Australia) . Please ...
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385 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 ...
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4k views

Proj4js Problem in converting coordinates from google mercator

I am a really beginner into web-cartography, so sorry if this subject is rudimentary or basic but I truly search for a long time and I am still stick in it. So the problem is: I don't understand why ...