====== Coordinate System ======

===== Global Frame =====
The global frame is such that the x,y origin is at the pinger, and z=0 is at the surface. Positive z is up. Yaw is relative to magnetic north. Pitch and Roll are relative to the gravity vector.


===== Axes =====

  * X+ - front of the sub
  * Y+ - left of the sub
  * Z+ - above the sub

===== Rotations =====

  * Yaw+ - Counterclockwise around Z+ axis (this is opposite of magnetic) (Yaw **Left** positive)
  * Roll+ - Counterclockwise around X+ axis (Roll **Right** is positive)
  * Pitch+ - Counterclockwise around Y+ axis (Pitch **Down** is positive)


===== TF Frames =====

  * ''world'' - Global frame defined above
  * ''cobalt'' - The frame defining the sub's orientation relative to the ''world'' frame based upon the localization node output.
  * ''cobalt_sim'' - The frame defining the sub's orientation relative to the ''world'' frame based upon Gazebo's output.

==== TF Graph ====

A visual representation of the TF tree will be placed here in future.