I am trying to understand the difference between the two coordinates system. By so far I grasp that EPSG:3857 is used for a web-based map like Google Maps, OpenStreetMap.
I am getting a position (in lat,lon or EPSG:4326). Now my task is to figure out where it is next through its velocity(heading and speed) and time duration of the measurement.
new_pos = old_pos + velocity * time
Realise that the equation needs to be in meter calculation.
I then proceed to
- Converted lat,lon into EPSG:3857
- Perform calculation
- Converted them back into lat,lon
- Plotted the points onto a map based on EPSG:4326
and the points were far off the next measured point
Then I repeated the calculation except using UTM coordinates. The results were much better (as shown above by blue point)
I reckon the distance measurement should be roughly similar(1unit to 1 m...am I right?
I am working near the equator).
So I am wondering what is wrong down here and which measurement should I take?