Post-concussion syndrome. Post-concussion syndrome, also known as postconcussive syndrome or PCS, is a set of symptoms that may continue for weeks, months, or a year or more after a concussion â a mild form of traumatic brain injury (TBI).
The Equatorial (Celestial) Coordinate System. Equatorial coordinates, also called simply celestial coordinates, are the standard coordinate system for the sky. It is meant for the fixed sphere of the stars within which the Earth and Sun move.
Azimuth is measured from the north point (sometimes from the south point) of the horizon around to the east; altitude is the angle above the horizon. The horizontal coordinate system is a celestial coordinate system that uses the observer's local horizon as the fundamental plane.It is expressed in terms of altitude (or elevation) angle and azimuth.he horizontal coordinate system is a celestial coordinate system that uses the observer's local horizon as the fundamental plane.