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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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 ...
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Mercator projection: formula for latitude based on pixels?

I am basing this question on knowledge from a previous one: Mercator projection: problem with latitude formula In that question/answer, the formula is given for working out how many pixels above/...
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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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Gdal: How to reproject from equirectangular to mercator?

I work with raster ETOPO1, made a crop of my area of interest. curl -L -C - 'http://www.ngdc.noaa.gov/mgg/global/relief/ETOPO1/data/ice_surface/grid_registered/georeferenced_tiff/ETOPO1_Ice_g_geotiff....
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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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321 views

image rectification with Mercator projection

I have written an image rectification function which allows a user to select 2 points on an image and 2 points on a map. The function will then rectify the image so it is translated, scaled and ...
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105 views

Drawn figure looks stretched

I have written some code which offset a certain latitude and longitude with a distance in centimeters. What I am trying to do is based on a coordinate and a vector create two new points along the line ...
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1answer
256 views

osm2pgsql missing coordinates

I am quite new to GIS and OSM and am trying to get my head around exporting custom OSM region and uploading them into PostgreSQL. I have started with a very small map area to export with only two ...
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Converting GPS Positions to Google Maps

I have a set of GPS-coordinates in a database, which I want to compare to a coordinate supplied by the html5 location API. My coordinates look like this: <WGS84Coordinates> ...
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911 views

Compute the latitude of a center of mercator projection

Say I'm looking at a portion of a map that's displayed using Mercator projection with the view bounded at 40°N and 20°N. How do I compute the latitude of the point that's in the centre of that view? ...
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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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Re-project raster image from Mercator to Equirectangular

I have a raster image of the world map in Mercator projection, square 1:1 format. I want transform the image into an Equirectangular projection accurately. I assumed from my research that GDAL would ...
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Historical maps as cylindrical projections

Objective: I want to overlay old, historical maps on top of Google Maps. According to Wikipedia, Google Maps uses a variant of the Mercator projection, a close relative of cylindrical projections. ...
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973 views

Why does Transverse Mercator projection have scale factor?

Why does the Transverse Mercator projection have a scale factor in ArcGIS and the standard Mercator projection not? In other words what is the difference between these two projections beside being a ...
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Mercator bias plot in Leaflet

I was inspired by this wikipedia image from the mercator projections page to hack around with leaflet. The idea was to interactively have your cursor move a continent and that it would be corrected ...
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1answer
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how to compute tile row from latitude in mercator projection

I work on google tile images. I want to compute a tile row from its latitude. How can I do that. I know that tile system cover all of the earth from -85 latitude to 85 latitude. 4 tiles exists at the ...
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Pseudo-Mercator projection with Decimal Degrees?

Hope this isn't a duplicate, did some searching but none seemed quite the same. Projection I want: WGS84/Pseudo-mercator. Selected. Looks Great. Canvas units I want: Decimal Degress. Selected. ...
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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 ...