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I am trying to map GPS points (lat, long) onto a 2D (X, Y) plane. The plane is drawn on an Android device using a custom view, and I want each axis to scale to 200 meters in length.

I'm trying to set a GPS location as the origin of this plane, and then map points which are up to 100 meters away from this GPS point onto the map.

I've done some prior research but the threads I'm finding address converting from Lat/Long to (X, Y, Z) spherical coordinates, in which the earth is the origin (see this thread).

Another thread is more along the lines of what I'm looking for, in which each pixel on the screen corresponds to a GPS location -- however, I am trying to map the GPS points onto a much smaller scale (200m X 200m).. not a large geographic map like a city.

What would be the most straightforward way to go about doing this?

Edit: Found a very similar question, but instead of using a coordinate plane, it uses an image of a floor plan to map GPS points to.

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Tarif Haque
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  • Over a small distance, you can convert from fractional degrees to linear distance without substantial error. Geometry will show that a degree of latitude is essential the same fraction of the earth's circumference anywhere, but a degree of longitude varies in distance depending on the latitude. So figure out the local degree-to-distance conversions and apply them. – Chris Stratton Jul 15 '13 at 01:30
  • Okay.. this makes enough sense. How do I figure out the local degree-to-distance conversions? The math is new to me.. So does a 1 degree of latitude = 1/180 of the distance between the north and south pole (so half the circumference of the Earth?) – Tarif Haque Jul 15 '13 at 18:04

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If your area is very small,it seems that you can ignore of z axis.Really for little area on the earth,if (x1,y1,z1) and (x2,y2,z2) be two points on it,you can use z1 as good approximation of z2 or versa.So you can map them to (x1,y1) and (x2,y2) on the 2D cartesian map without great error.

hasanghaforian
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