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tu-darmstadt-ros-pkg / hector_gazebo

hector_gazebo provides packages related to the simulation of robots using gazebo (gazebo plugins, world files etc.).
http://www.ros.org/wiki/hector_gazebo
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hector gps plugin showing constant latittude and longitude values. #62

Open ghost opened 5 years ago

ghost commented 5 years ago

Hi,

I am using the gazebo_ros_gps sensor from the hector_gazebo plugins. I am getting the lattitude, longitude and altitude values from this. However the latitude and longitude values seem to be constant at approx 49 and 8 respectively even if i translate the robot in the X and Y direction. When i translate the robot to a height and make it free fall the altitude value keep changing which means my altitude is working fine. Can someone explain to me how this readings are working and if i am taking these values in the sense it should be taken? Also are these values showing the real world coordinates? As in is it showing the coordinates of for where i am working with gazebo or is it doing some kind of mapping of gazebo coordinates to geocoordinates? How is it mapping?

StefanFabian commented 5 years ago

Disclaimer: I did not work on this software and cannot give any support regarding it.

Is the latitude and longitude not changing at all or are the changes just very small? If it follows the earth model, 1 degree of latitude is 60 arc minutes with one arc minute being up to 1.82 kilometers. Hence, a movement of a few meters will be only a very tiny fraction of a degree latitude or longitude.
You may want to do some reading regarding the Global Positioning System and earth models.