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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.

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Is azimuth preserved in EPSG:3857?

I am trying to draw the outlines of drone images using OpenLayers. The drone has recorded a "yaw degree", which should be the azimuth. However, when I place the rectangles on the map, their ...
Džuris's user avatar
  • 111
2 votes
1 answer
69 views

ST_OrientedEvelope returning parallelogram instead of rectangle

I have a GIS application with multiple polygons where I'd like to get the bounding box of the polygons. The ST_Envelope function works as expected. Because the map is rotated the polygons always ...
Ricardo Mayerhofer's user avatar
2 votes
2 answers
110 views

Converting Mercator tile coordinate to an OL TileGrid coordinate in OpenLayers?

Is there a method to convert the normal {z}/{x}/{y} endpoints you would get from a tile service into an OpenLayers TileGrid tile? Here is a mercator tile with coords: However in OpenLayers the ...
Malcolm's user avatar
  • 489
2 votes
0 answers
62 views

The true size of something when 'on the fly' moving around in EPSG:3857

I know this should be a trivial question, but I still will ask it as I have a knot it my head... The Web Mercator is distorting shapes and areas further from the equator. This is why Greenland is so ...
Lenn's user avatar
  • 1,297
1 vote
1 answer
206 views

If a scale bar measures incorrectly in the web mercator projection, how can it be correct in Google Maps?

I've started to read a bit more into coordinate systems, projections and the problems around them and so far I understand that in the WGS 1984 Web Mercator (auxilliary sphere) coordinate system a ...
danielaandrea's user avatar
1 vote
0 answers
463 views

GeoServer doesnt generate tiles for EPSG:3857 grid

I failing to generate .geojson tiles with GeoServer for grid with EPSG:3857 projection. Note that it successfully generate .png tiles with the same config, and also .geojson generation works for other ...
Philip St's user avatar
3 votes
1 answer
934 views

Convert a point on a flat 2D web-mercator map image to a Coordinate

I have an image of a map and a point marked onto it. I have those coordinates (as a percentage) inside the image of the point. Now I'd like to know the coordinate (latitude/longitude) that this point ...
Georg's user avatar
  • 1,001
2 votes
1 answer
616 views

Convert image from EPSG:4326 to EPSG:3857

I'm new to GDAL and map projections, I need to convert equirectangular (EPSG:4326?) projection to "pseudo Mercator" (EPSG:3857?) projection used by 90% web-based maps (which is simple this 0/...
Martin's user avatar
  • 141
0 votes
0 answers
56 views

Size of area in Web Mercator

I downloaded a satellite image from Sentinel Hub. I requested a 10,000 x 10,000m image in Web Mercator (EPSG:3857). Here is a piece of code that I use: bbox = BBox(bbox=[x, y, x + 10000, y + 10000], ...
Alexey's user avatar
  • 111
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0 answers
151 views

Error in WGS84 to Mercator coordinate transformation

I'm trying to convert the (lat,lon) of WGS84 into Mercator (x,y). Below I've listed all the relevant information given in the file. Datum="WGS84" Ellipsoid="WGS84" ...
Pixel_Bear's user avatar
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63 views

Negative latitude after calculating position from tile name

I am using Geoserver to generate tiles and I want to get Lat/Lon from tile file name. I use the following functions from (https://wiki.openstreetmap.org/wiki/Slippy_map_tilenames#ECMAScript_(...
super_mario981's user avatar
0 votes
0 answers
80 views

Cache feature lengths are in Web Mercator, what is the conversion factor to miles?

I have a cache polyline feature with a Shape_Length field calculated in Web Mercator. I need to convert that feature length to feet or miles. I am using the Value Conversion tool in Dashboards !!...
SaltyPatriot's user avatar
1 vote
2 answers
71 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 ...
filimonic's user avatar
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1 answer
842 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 ...
baggiponte's user avatar
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0 answers
71 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 ...
rks's user avatar
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0 answers
885 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 ...
Optimus_2016's user avatar
5 votes
1 answer
371 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 ...
Basile's user avatar
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1 vote
1 answer
614 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 ...
reducing activity's user avatar
4 votes
1 answer
613 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 ...
Attila O.'s user avatar
  • 223
0 votes
1 answer
208 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 ...
user81371's user avatar
2 votes
0 answers
86 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 ...
Jon Seymour's user avatar
2 votes
1 answer
144 views

Fixing misshaped GeoJSON polygons [closed]

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 ...
3rgo's user avatar
  • 129
1 vote
1 answer
499 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 ...
VeryNewUser's user avatar
0 votes
2 answers
1k views

Using 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 than WGS 84 (SRID 4326) or Web Mercator (SRID 3857)?
Maxinef23's user avatar
2 votes
0 answers
163 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, ...
zakjan's user avatar
  • 214
0 votes
1 answer
1k 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 ...
Lieutenant Dan's user avatar
0 votes
0 answers
103 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, ...
philipp's user avatar
  • 101
0 votes
1 answer
745 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. ...
Moritz's user avatar
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1 vote
0 answers
220 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: ...
Frank Conry's user avatar
1 vote
1 answer
198 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 ...
vinni's user avatar
  • 175
2 votes
2 answers
3k 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 ...
ericg's user avatar
  • 121
0 votes
2 answers
435 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 ...
Justas Brazauskas's user avatar
2 votes
1 answer
369 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 ...
Mike Jackson's user avatar
5 votes
1 answer
7k 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, ...
nickponline's user avatar
3 votes
1 answer
687 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 ...
Broccoli's user avatar
  • 168
1 vote
0 answers
258 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 ...
Lowip's user avatar
  • 111
0 votes
0 answers
167 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 ...
Alešinar's user avatar
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1 vote
0 answers
334 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 ...
pgager's user avatar
  • 447
0 votes
2 answers
2k 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 ...
Matti Wens's user avatar
1 vote
1 answer
1k 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 ...
ePascoal's user avatar
  • 951
1 vote
1 answer
312 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((...
Srinivas's user avatar
  • 135
1 vote
1 answer
1k 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....
dr_times's user avatar
  • 938
9 votes
3 answers
28k 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/...
TPPZ's user avatar
  • 427
1 vote
0 answers
143 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
2 votes
2 answers
411 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-...
Karim's user avatar
  • 21
4 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, ...
Steve Kuo's user avatar
  • 171
5 votes
4 answers
3k 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 ...
Juhele's user avatar
  • 1,738
4 votes
0 answers
5k 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 ...
Kevin Krumwiede's user avatar
2 votes
1 answer
6k 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 ...
Aaron Kreider's user avatar
0 votes
1 answer
3k 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
a1234's user avatar
  • 901