Questions tagged [web-mercator]

Web Mercator a.k.a WGS 84 / Pseudo-Mercator -- Spherical Mercator, is a projected coordinate system used for rendering web maps in applications like Google Maps and OpenStreetMap. The area of use is limited to World maps between 85.06°S and 85.06°N.

Filter by
Sorted by
Tagged with
1 vote
2 answers
26 views

Dynamically build quadtiles compatible with spherical Mercator (mathematics)

I have a spherical Mercator map in degrees coordinates (-180, -85, 180, 85) programmed. I add points to it one-by-one, and on some condition (ex, there are more than 25 points on map), I split this ...
user avatar
  • 133
0 votes
1 answer
142 views

Is OpenStreetMaps's Nominatim "Centre Point" the centroid and what EPSG is it?

I looked up a couple of places on OpenStreetMap's Nominatim, like Bruck an der Mur, and I could not confirm whether the reported coordinates are indeed the same thing as the centroid, and which EPSG ...
user avatar
0 votes
0 answers
45 views

Does setting appropriate SRID make diffrence to rendering peformance?

I understand that PostGIS allows us to set SRID on geometry or geography. But I am just wondering if it would actually impact the rendering performance on the client side. For instance, let's say I ...
user avatar
  • 1
0 votes
0 answers
43 views

Adding metre distances to Web Mercator projection

I'm new to using GPS and using map projections. I've read quite a bit but I'm struggling to understand how to use Web Mercator projection. I have lat/long coordinates from the nuScenes dataset. The ...
user avatar
5 votes
0 answers
105 views

TMS tilenames for Elliptical Mercator projection - EPSG:3395

My goal is to derive TMS tile names from given lat/lon and vice versa for Elliptical Mercator projection (EPSG:3395) using Python. OSM wiki explains the logic for Spherical Mercator (EPSG:3857), but ...
user avatar
  • 3,343
1 vote
1 answer
263 views

Generate polygon shaped as a circle if projected using Web Mercator, in Python?

I need to solve problem very similar to Generating polygon representing rough 100km circle around latitude/longitude point using Python? but subtly different. I need a shape that will be a circle once ...
user avatar
4 votes
1 answer
192 views

Reproject EPSG:3857 to Gnomonic projection using GDAL

I'm trying to reproject Mapbox maps from whatever projection they come in (which I believe is EPSG:3857) to what I believe should be a Gnomonic projection. Let me try to be more clear actually. I'd ...
user avatar
  • 223
0 votes
1 answer
42 views

Get UTM regions overlapping with a geojson polygon

how can I get the list of UTM grids overlapping with a geojson polygon in web mercator? I am trying to download data off of Sentinel, and I am seeing if I can go directly from an input polygon to ...
user avatar
2 votes
0 answers
34 views

Meaning of statement in GRASS r.horizon manual

I have a question about this statement in the r.horizon manual: "If your projection is based on distance (easting and northing), these too must be in meters. The buffer parameters must be in the ...
user avatar
2 votes
0 answers
76 views

Fixing misshaped GeoJSON polygons

In 2018 Ghana changed its administrative divisions (from 11 to 16 regions, and from 216 to 260 districts). Unfortunately, I have not been able to find the GeoJSON (or equivalent) data for the new ...
user avatar
  • 129
1 vote
1 answer
89 views

How to transform Google/OpenStreetMap Co-ordinates to ESPG:3857 Co-ordinates?

I have an old map successfully layered on OpenStreetMap on QGIS and have been able to add delineated text points from a CSV file using WGS 84 / Pseudo-Mercator ESPG:3857 co-ordinates. I have tried ...
user avatar
0 votes
2 answers
99 views

Is there any reason to use or know anything other than WGS 84 (SRID 4326) or Web Mercator (SRID 3857)? [closed]

I'm new to GIS and learning about SRIDs. Are there still other relevant or commonly used SRIDs?
user avatar
2 votes
0 answers
70 views

How to project an image with gdalwarp to cover a Mapbox map?

I'm trying to re-project a geographical raster source covering entire world (temperature data from GFS) to Web Mercator with this command: gdalwarp -t_srs EPSG:3857 input.grib output.tif However, ...
user avatar
  • 204
0 votes
1 answer
514 views

Convert pixel x,y position on map to latitude and longitude

My map takes up 100% width and height of the browser screen.. I have a draggable div that is super imposed over the map, I am am capturing this divs position using offset(); to get the pixel top and ...
user avatar
0 votes
0 answers
44 views

proj.4 — problems to understanding the projection result

I am using pro4js for a webproject to project data obtained from the Openstreetmap database. Basically I have this code (javascript/ES 6): const //some coordinates we = { lon: 50.9802813, ...
user avatar
  • 101
0 votes
1 answer
322 views

Reproject Geoserver layer in Web Mercator Mapbox frontend

I am looking to visualise live satellite imagery in a Mapbox GL JS Fronend. There exists a Geoserver instance which has exactly the resource I want to use. However, the layer is in the wrong EPSG. ...
user avatar
  • 21
1 vote
0 answers
134 views

Changing Map Coordinate System Changes in ArcGIS Pro Changes Azimuth

I am trying to create a label that will overlay a line in ArcGIS Pro, the layer is coming from a PostGIS database. The underlying materialized view for the label/symbol overlay is something like this: ...
user avatar
1 vote
1 answer
133 views

Normalize OSM geometry to 1x1 coordinate system

I'm extracting a couple of geometries with overpass turbo and need to "normalize" their shape from lat-lon to [[0-1][0-1]] coordinates. The first thing I've tried is probably pretty wrong: get ...
user avatar
  • 175
2 votes
2 answers
1k views

Computing distance between two spherical Mercator points

I am computing the Mercator points according to the top answer at Convert latitude/longitude point to a pixels (x,y) on Mercator projection. Now that I have two Mercator points on a spherical ...
user avatar
  • 121
0 votes
2 answers
253 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 ...
user avatar
2 votes
1 answer
248 views

GDALWARP cuts off right edge of image?

I'm reprojecting GFS GRIB files to EPSG:3857 using gdalwarp. Resulting file get little bit shorter to the right so when I zoom in from zoom level 5 and higher, I can see vertical line with missing ...
user avatar
4 votes
1 answer
5k views

Converting a pixel coordinate in GeoTIFF to a latitude and longitude?

I have a GeoTIFF with the following meta information: PROJCS["WGS 84 / Pseudo-Mercator", GEOGCS["WGS 84", DATUM["WGS_1984", SPHEROID["WGS 84",6378137,298.257223563, ...
user avatar
3 votes
1 answer
409 views

Differences in angle measurements in Web Mercator

I am trying to measure different angles on 2D map using lat/lon coordinates taken from Google Maps, and Java library JTS. I have noticed a weird thing: my measurements are always distorted, except ...
user avatar
  • 168
1 vote
0 answers
214 views

Converting latitude/longitude to full range referential

I have a list of latitudes and longitudes expressed as follow: -1 <= latitude <= 0 0 <= longitude <= 1 Those coordinates represent POIs on a fantasy map displayed using the Leaflet ...
user avatar
  • 111
0 votes
0 answers
102 views

Projecting EUMETSAT precipitation data

I downloaded the H05 – PR-OBS-5 Accumulated precipitation at ground data from H-SAF. The Product User Manual states the dataset is in rectangular stereographic projection centred on 42°N, 10°E. I need ...
user avatar
  • 720
1 vote
0 answers
209 views

Why don't public organizations support Web Mercator EPSG 3857 for WMS? [closed]

Given that Web Mercator is the defacto standard for web mapping and all basemaps (Google, ESRI, Mapbox) are based on this coordinate system.. Why do many organizations e.g. NOAA not publish their WMS ...
user avatar
  • 449
0 votes
2 answers
1k views

MapBox or Google Maps Static API: Extent or bounding box of image?

I'm using the MapBox or Google Maps Static API to get map images. I understand that the centre of the image is specified in terms of latitude and longitude, but is there any way to either specify or ...
user avatar
1 vote
1 answer
741 views

Open Basemap in different Projection (Transverse Mercator) - QGIS

I have data in a transverse Mercator projection which is a different projection from my base map (Spherical Mercator / Web Mercator / pseudo-Mercator). I really would like to create a map in a TM ...
user avatar
  • 901
1 vote
1 answer
219 views

Difference in Spherical Mercator(google/mapbox/supercluster code) calculation and Postgis 3857

As per source code of supercluster, google map utils and mapbox formula to convert (lng, lat) to spherical mercator is as x = lng/360 + 0.5; siny = Math.sin(Math.toRadians(lat)); y = 0.5 * Math.log((...
user avatar
  • 135
1 vote
1 answer
828 views

Reprojecting from MODIS Sinusoidal to Web Mercator: how to calculate output raster dimensions?

I have a MODIS image from AWS in sinusoidal projection and I want to calculate output raster size after reprojecting it into Web Mercator (EPSG:3857). $ gdalinfo MCD43A4.A2017185.h11v03.006....
user avatar
  • 908
6 votes
3 answers
19k views

Convert GPS coordinates to Web Mercator EPSG:3857 using python/pyproj

I've created a couple of functions using the math package from python 3.5 to transform GPS coordinates to x/y web mercator (pseudo mercator) as explained here: http://wiki.openstreetmap.org/wiki/...
user avatar
  • 335
1 vote
0 answers
123 views

satellite imagery basemap for webmapping application

I am currently trying to develop a small webmapping application to show some point data which covers the whole planet. I do want to use projections different from webmercator, like Robinson ...
user avatar
  • 191
2 votes
2 answers
307 views

Problem aligning points near North Pole using Web Mercator with QGIS and Google Street View

This is my first time using QGIS 2.18. I created a project with EPSG:3857. Added OpenLayers Plug-in to use Google Street View as a map for the points and data I want to work on. I love self-...
user avatar
  • 21
3 votes
2 answers
2k views

Convert UTM to Web Mercator

I'm looking to programmatically convert UTM to Web Mercator (a.k.a. Spherical Mercator, EPSG:3857, EPSG:3785, OpenLayers:900913). I'm looking for the algorithm, or something that runs on iOS (Swift, ...
user avatar
  • 161
5 votes
4 answers
2k views

Understanding strange measure distance results from QGIS?

My colleague just told me about incorrect measure distance tool results in QGIS. For reference we used this pond. While our local map provider Mapy.cz and Google Maps: both show about 970 meters ...
user avatar
  • 1,708
4 votes
0 answers
4k views

Converting lat/long to EPSG:3857 coordinates

The map widget I'm using gives me click locations in lat/long. I need to convert those coordinates to EPSG:3857 to query a database. Most of the solutions I've found use the formula described in ...
user avatar
2 votes
1 answer
5k views

How do I convert tile pixels to longitude and latitude for web mercator?

I need a function to convert from tile pixels (x, y) from the Web Mercator projection (aka EPSG::3857 or SRID 900913), to longitude and latitude. I'd like the function to be written in pseudo-code or ...
user avatar
0 votes
1 answer
2k views

Project from GCS_WGS_1984 to WGS_1984_Web_Mercator_Auxiliary_Sphere

What is the default transformation method to project data from from GCS_WGS_1984(WIKI 4326) to WGS_1984_Web_Mercator_Auxiliary_Sphere(WIKI 3857)? ArcMap 10.3.1
user avatar
  • 901
0 votes
1 answer
1k views

Command line tool for reading .shp, .prj and converting to Google Maps lat lngs

I have a data file exported from an ARCGIS system (parcel data from local government). Its a zip file containing 7 files: f.dbf, f.prj, f.sbn, f.sbx, f.shp, f.shp.xml, f.shx. I have a simple ruby ...
user avatar
1 vote
0 answers
745 views

Transform projection with SharpMap

I have SharpMap loading a shapefile and displaying the rendered image to a PictureBox. If I open the shapefile in QGis I can see the SRC: +proj=merc +lon_0=100 +lat_ts=-41 +x_0=0 +y_0=0 +datum=...
user avatar
1 vote
1 answer
316 views

Where to get world-map images for use in webglearth

I am using webglearth for a 3D earth globe. I already bought MapTiler, from the same makers. Now I am struggling with finding different world-map-images with the right projection. I need either WGS ...
user avatar
3 votes
1 answer
723 views

Web Mercator to 3d globe projection problems

I've been trying to use map tile images from services like OpenStreetMap to create a globe, and I've mostly succeeded. The problem is that when I compare my globe to one using the same image source ...
user avatar
  • 51
9 votes
1 answer
13k views

Leaflet GeoJSON with projected coordinates (3857)

I am trying to get a GeoJSON with projected coordinates to show in Leaflet. I have no problems loading GeoJSON with lat/lng (EPSG:4326). Here is a fiddle where I load the GeoJSON with unprojected lat/...
user avatar
3 votes
4 answers
5k views

How to georeference a tile downloaded from Google Maps

I'm trying to georeference a set of image tiles downloaded from a Google Maps site. Based only on each image's Google Maps grid reference and zoom level, how can I calculate the real-world coordinates?...
user avatar
  • 20.5k
0 votes
1 answer
376 views

Are with WebMercator the X and Y extents identical?

I am calculating the tile coordinates in a WebMercator projection at different zoom levels and have the following problem: Cartopy suggests that the projection extent in meters is slightly different ...
user avatar
  • 1
9 votes
2 answers
6k 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 ...
user avatar
  • 425
1 vote
1 answer
232 views

Alternative to Web Mercator projection that does not look too small on phone?

My issue with Web Mercator as a projection to use online is that I think it gives people an unrealistic perception of space. Greenland looking massive is a good example. One benefit of Web Mercator, ...
user avatar
2 votes
1 answer
2k views

Reprojecting from Lambert Conformal Conic into EPSG:3857?

I'm trying to reproject a plain png image file into EPSG:3857 for use in an OpenLayers application. I'm pulling the image from the NWS site at: http://rapidrefresh.noaa.gov/HRRR/for_web/hrrr_ncep_jet/...
user avatar
  • 21
1 vote
2 answers
1k views

Scalebar gives error in measurement in Qgis: Different measurements of distance on OSM tiles and GoogleEarth

I've created a map of Bordeaux using the QGIS map compositor by following this procedure: Used the OSM plugin to display an OSM map and zoomed to Bordeaux Used the print composer to create a map of ...
user avatar
0 votes
1 answer
1k views

Issue on Exporting Shapefile Points to Google Map Longitude & Latitude?

Using ArcGIS 10.2 and Some points in Shapefile with BC Albers Coordinate System I am having problem on Getting Points Longitude & Latitude in Google Map Coordinate System. What I have is a CSV ...
user avatar
  • 534