Place GPS coordinates on a map image without external API

Question

I'm currently working on a "trip tracker". The goal is to place some GPS coordinates (logged by a GPS device) on a static image map downloaded from MapQuest (or OpenStreetMap). In order to achieve this goal, I followed to follwing procedure:

Find my GPS coordinates set's center ((maxLat-minLat)/2, (maxLon-minLon)/2)
Download a 3840x3840 map (fixed zoom 15 for now) centered on my "coordinates set's center" from MapQuest
Using mercator projection (I tries both spherical & eliptical with EPSG:4326 or EPSG:3857), get the (X,Y) of the center in meters
For each point of my set
Get the point's (X,Y) using mercator projection
Substract the point(X,Y) to center(X,y)
Convert meters to pixel according to Zoom level and map (tile?) width (I tried both tile width (256) and map width (3840)

Unfortunatly, in one week of research & tries, I didn't succeed in placing those point.

Does anybody have a complete solution for this kind of problems ?

Thank you

Edit #1

(Removed: inconsistent)

Edit #2

Here is a clean project sample

https://dl.dropboxusercontent.com/u/429726/MapSample.zip

The path is rotate of 90° (tricked @MainWindow.xaml.cs:L130)
The path is flattened

Img: https://dl.dropboxusercontent.com/u/429726/MapSample.jpg

Edit #3

Added multiple formulas

GeographicCoordinates > ToMercator() modification

public System.Windows.Point ToMercator(int test = 0)
{
    System.Windows.Point mercator;
    double x = this.Longitude.ToMercator(test);
    double y = this.Latitude.ToMercator(test);
    mercator = new System.Windows.Point(x, y);
    return mercator;
}

GeographicCoordinate > ToMercator() modification

public double ToMercator(int test = 0)
{
    double result = 0;
    switch (this.Type)
    {
        case(GeographicCoordinateType.Longitude):
            switch (test) { 
                case 0:
                    return this.DecimalDegrees.ToRadians() * Maps.EarthGreatRadius;
                case 1:
                    //http://jackofalltradesdeveloper.blogspot.be/2012/03/how-to-project-point-from-geography-to.html
                    return this.DecimalDegrees * 0.017453292519943 * 6378137;
                case 2:
                    //http://alastaira.wordpress.com/2011/01/23/the-google-maps-bing-maps-spherical-mercator-projection/
                    return this.DecimalDegrees * 20037508.34 / 180;
            }
            break;
        case(GeographicCoordinateType.Latitude):
            switch (test)
            {
                case 0:
                    double latitude = this.DecimalDegrees;
                    if (latitude > 89.5)
                    {
                        latitude = 89.5;
                    }
                    if (latitude < -89.5)
                    {
                        latitude = -89.5;
                    }
                    double temp = Maps.EarthGreatRadius / Maps.EarthGreatRadius;
                    double es = 1.0 - (temp * temp);
                    double eccent = Math.Sqrt(es);
                    double phi = latitude.ToRadians();
                    double sinphi = Math.Sin(phi);
                    double con = eccent * sinphi;
                    double com = 0.5 * eccent;
                    con = Math.Pow((1.0 - con) / (1.0 + con), com);
                    double ts = Math.Tan(0.5 * ((Math.PI * 0.5) - phi)) / con;
                    double y = 0 - Maps.EarthGreatRadius * Math.Log(ts);
                    return y;
                case 1:
                    double FSin = Math.Sin(this.DecimalDegrees.ToRadians());
                    return 6378137 / 2.0 * Math.Log((1.0 + FSin) / (1.0 - FSin));
                case 2:
                    y  = Math.Log(Math.Tan((90 + this.DecimalDegrees) * Math.PI / 360)) / (Math.PI / 180);
                    return y * 20037508.34 / 180;
            }
            break;
        default:
            throw new Exception();
    }
    return result;
}

Edit #4

I've tried multiples formulas & Proj.Net library, I always end up with the same shape (-90° && "flatened")

If you're looking for a complete solution, you are on the wrong site. You need to show what you've tried, preferably with some code. — djv, Oct 13 '14 at 18:28
Did you read [slippy map tilenames](https://wiki.openstreetmap.org/wiki/Slippy_map_tilenames) in the OSM wiki? — scai, Oct 13 '14 at 19:23
I did read the slippy map tiles name doc & the zoom level related one. I'll provide some pieces of code in order to to show you some methods I tried. — Booster2ooo, Oct 14 '14 at 08:58

score 0 · Answer 1 · edited May 23 '17 at 11:43

0

The map coordinates need also translate to mercator. You need delta x and delta y of the map and the image properties:Convert lat/lon to pixel coordinate?.

edited May 23 '17 at 11:43

Community

1
1

answered Oct 15 '14 at 15:08

Micromega

12,486
7
35
72

score 0 · Answer 2 · answered Oct 15 '14 at 15:16

0

I've used this in the past to build information on a map on a Windows Form client:

http://greatmaps.codeplex.com/

answered Oct 15 '14 at 15:16

Martin Milan

6,346
2
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Booster2ooo · Answer 3 · 2014-10-17T13:32:55.327

Here is the answer

GeographicCoordinates > ToMercator()

public System.Windows.Point ToMercator(int test = 0)
{
    System.Windows.Point mercator;
    double x = this.Longitude.ToMercator(test);
    double y = this.Latitude.ToMercator(test);
    mercator = new System.Windows.Point(x, y);
    return mercator;
}

Should be

public System.Windows.Point ToMercator(int test = 0)
{
    System.Windows.Point mercator;
    double x = this.Latitude.ToMercator(test);
    double y = this.Longitude.ToMercator(test);
    mercator = new System.Windows.Point(x, y);
    return mercator;
}

And GeographicCoordinate > ToMercator() should swap GeographicCoordinateType.Latitude/Longitude cases.

I also had to fix Y according to the hemisphere

& the job was done.

Place GPS coordinates on a map image without external API

Edit #1

Edit #2

Edit #3

Edit #4

3 Answers3