Plain English Meaning

It is the FAA rulebook that a GPS-with-WAAS sensor has to pass to be approved for use in aircraft. A TSO-C145A unit is the position-finding part that feeds another system in the cockpit — it does not have its own controls and display for the pilot to fly the GPS directly.

Full Definition

An FAA Technical Standard Order that sets the minimum performance standards a GPS sensor must meet when it relies on WAAS augmentation to provide position data to other avionics. Equipment built and approved to TSO-C145A is a GPS/WAAS sensor — it produces position information for use by a separate navigation system (such as a or integrated ), rather than functioning as a standalone navigator with its own interface.