I am using realistic street networks imported from OpenStreetMap for simulations with Veins, for example the Luxembourg scenario from Lara Codeca. Now, to prepare a visualisation (using Google Earth), I want to export the vehicle positions in the simulation from SUMO or OmNET coordinates to GPS coordinates.
As material I have the OSM file used for generating the scenario, including the GPS positions of all nodes there. I was hoping to find a simple mapping from the simulation coordinates to GPS coordinates, for example, by knowing the GPS coordinates of the corners of the bounding box and the simulation playground.
Is there a simple way to make this conversion, and how can I find the actual corners that were used by the OSM conversion when generating the playground?
The conversion works as follows:
1. Accessing the Location Information from OmNET
// Adapt your path to the mobility module here
Veins::TraCIMobility* mobility =
check_and_cast<Veins::TraCIMobility*>(
getParentModule()->getSubmodule("veinsmobility"));
Veins::TraCICommandInterface* traci = mobility->getCommandInterface();
Coord currPos = mobility->getCurrentPosition();
std::pair<double, double> currLonLat = traci->getLonLat(currPos);
getLonLat()
returned absolute 2D coordinates for me, so there is a conversion step required.
2. Finding the Transformation
The .net.xml file from SUMO contains the required transformation. The <location>
tag contains the attributes netOffset
and projParameters
that are needed.
For the Luxembourg scenario, these are
netOffset="-285448.66,-5492398.13"
projParameter="+proj=utm +zone=32 +ellps=WGS84 +datum=WGS84 +units=m +no_defs"
3. Inversing the Transformation
The library PROJ.4 can be used to do the inversion. A Python interface is also available (pyproj).
import pyproj
projection = pyproj.Proj(
"+proj=utm +zone=32 +ellps=WGS84 +datum=WGS84 +units=m +no_defs")
# x, y obtained from OmNET
lon, lat = projection(x, y, inverse=True)
In case only the relative location information is available, the x, y values must be adjusted first by adding the netOffset values to them.
Edit
Only the first step is necessary when you build SUMO --with-proj-gdal
support, the result of getLonLat()
will be in the desired format immediately.