Pilot License and training resource | Flight Schools and Clubs | Aircrafts | Airports.
Sign Up
PilotOutlook is the largest online community of Pilots, Aviation Industry
      Professionals and Aviation Enthusiasts. It is also an authoritative resource on
      pilot training, licenses, aircrafts, airports and flight schools.
Log in to PilotOutlook

Not a member?
Signing up is easy.
Sign Up
Search PilotOutlook
Help us spread the word
Link to this page:
Tag this page:
AddThis Social Bookmark Button
More options...

GPS Components


Instrument Flying Handbook Menu >Navigation Systems >Area Navigation (RNAV)>GPS Components

GPS consists of three distinct functional elements: space, control, and user.

The space element consists of 24 Navstar satellites. This group of satellites is called a constellation. The satellites are in six orbital planes (with four in each plane) at about 11,000 miles above the Earth. At least five satellites are in view at all times. The GPS constellation broadcasts a pseudo-random code timing signal and data message that the aircraft equipment processes to obtain satellite position and status data. By knowing the precise location of each satellite and precisely matching timing with the atomic clocks on the satellites, the aircraft receiver/processor can accurately measure the time each signal takes to arrive at the receiver and, therefore, determine aircraft position.

The control element consists of a network of ground-based GPS monitoring and control stations that ensure the accuracy of satellite positions and their clocks. In its present form, it has five monitoring stations, three ground antennas, and a master control station.

The user element consists of antennas and receiver/processors on board the aircraft that provide positioning, velocity, and precise timing to the user. GPS equipment used while operating under IFR must meet the standards set forth in Technical Standard Order (TSO) C-129 (or equivalent); meet the airworthiness installation requirements; be “approved” for that type of IFR operation; and be operated in accordance with the applicable POH/AFM or flight manual supplement.

An updatable GPS database that supports the appropriate operations (e.g., en route, terminal, and instrument approaches), is required when operating under IFR. The aircraft GPS navigation database contains waypoints from the geographic areas where GPS navigation has been approved for IFR operations. The pilot selects the desired waypoints from the database and may add user-defined waypoints for the flight.

Equipment approved in accordance with TSO C-115a, visual flight rules (VFR), and hand-held GPS systems do not meet the requirements of TSO C-129 and are not authorized for IFR navigation, instrument approaches, or as a principal instrument flight reference. During IFR operations, these units (TSO C-115a) may only be considered as an aid to situational awareness.

Global Positioning System (GPS)
Function of GPS
Partner sites: Mobile A/B Testing | Shimply.com

Social Media Monitoring by SocialAppsHQ