These symbols represent how ERAM is tracking a target. They are always used in conjunction with FDBs, LDBs, and E-LDBs which are described in detail in the next section.
Free Track - A target is tracked by ERAM, but is not flying along the entered route.
Flight Plan Aided Track (Flat Track) - A target is tracked by ERAM and is flying along the entered route within a default tolerance of +/- 5 nm.
Coast Track - No target is being tracked. The target is below radar coverage or has logged offline. ERAM will continue the track movement in the last known direction and speed before the target disappeared. This will occur for 5 minutes and then the system will automatically delete the coasting track.