The document (now officially known as IS-GPS-200 ) is the fundamental technical specification for the Global Positioning System (GPS). It defines the interface between the Space Segment (satellites) and the Navigation User Segment (receivers), specifically for the L1 and L2 radio frequency links. Historical Evolution
The revolutionary step occurs when EMS integrates GPS with ICD interrogation. Modern ICDs (managed by programmers like the 200 series) can transmit their location via home monitors. When a patient dials 911, dispatchers using GPS coordinates can identify the nearest responder equipped with a "wand" (antenna) compatible with the 200-series. More critically, if an ICD delivers a shock, the device logs the GPS-tagged time and location. For a patient found unresponsive, EMS can place a 200-series interrogator over the chest, download a 30-second electrogram, and determine if the heart is in a shockable rhythm—all while en route to the hospital.
ICD-GPS-200 provides the mathematical definitions necessary for the user to compute a position:
: Designed with power efficiency in mind, the ICD-GPS200 is suitable for battery-powered devices, extending the operational life of portable and wearable applications.
The document outlines the logic flow for the receiver: