GPS track angle (Course over ground)
I have question about track angle. I use gpss_client(for CTurtle) and in topic fix (gps_common/GPSFix) which besides latitude, longitude, altitude, speed, DOP factors give track angle which definition in fix topic in short is Direction in degrees from north. So i use google and find that angle is relative direction of travel to a ground position(same as Course Over Ground). In gorund robots we can asumme that track is equal heading which in marine vessels must be corrected for wind and sea current ( http://en.wikipedia.org/wiki/Course_%... ). One definition of track angle is at: http://www.ehow.com/about_5584477_gps... So my question is how is track angle measured. If we use compas convention that this angle is measured from true north in clock wise direction so North is 0° and East is 90°. But i think here in ROS is opposite 0° is North and 90° is West(counter-clock wise direction.) I read that all coordinate systems in ROS are right-handed(and that counter-clockwise direction is positive directon. Well if someone uses track and know in which direction form North track angle is measured(CCW(left) or CW(right)), can that knowdlege share with me,and other ROS users in forum.
What i think is that track angle is measured form North(0°) to West(90°)in counter clockwise direction.(my GPs reciever is LS20030 from Locosys.)
