History: Coordinate Systems

+ There are three coordinate systems used:

+ __Lab Coordinates__ - Hall coordinate system where y goes against gravity, z is in the direction of the beam, and x is to the left when looking down the beam
+
+ __Target Coordinates__ - Origin at the center of the target. x goes with gravity, z is parallel to the ground in the direction towards the center of the BigBite ((BigBite Drift Chambers|drift chambers)) or ((neutron arm)). y is to the left looking down z
+
+ __Detector Coordinates__ - Origin specified by center of the first
+ plane of the ((BigBite Drift Chambers|drift chambers)) or ((neutron arm)). x is "down" in the dispersion direction, z is in the nominal direction of particles such that z = 0 is defined by the first plane of the drift chamber for BB and the front of the shielding for thee neutron arm's N1. y is defined so we have a right handed coordinate system.