Airports Authority of India (AAI) successfully conducted a light trial using GAGAN (GPS Aided GEO Augmented Navigation) based LPV Approach Procedures. India is the first country in Asia Pacific Region to achieve such a landmark.
Utility: UPSC, JPSC, BPSC Prelims & Mains Section: Science & Technology: SpaceTech/ Navigation Systems |
Key Points
- The successful trial is a great achievement and major milestone in the field of Air Navigation Services (ANS) in the history of the Indian Civil Aviation Sector.
- LPV (Localizer Performance with Vertical Guidance) permits aircraft-guided approaches without the need for ground-based navigational infrastructure.
- The service relies on the availability of GPS and GAGAN Geo Stationary Satellites.
- LPV is a Satellite-Based Procedure that will make it possible to land at airports not equipped with expensive Instrument Landing Systems, such as many small regional and local airports
About LPV
- Localizer Performance with Vertical Guidance (LPV) is a subset of the Area Navigation (RNAV) Approach.
- Approaches to LPV minima have characteristics that are very similar to an Instrument Landing System (ILS) approach.
- The fundamental difference between the two is the source of the guidance signals.
- Whilst an ILS is a ground-based approach, necessitating the associated transmitters and antennae for each individual runway.
- The source for RNAV LPV guidance is the space-based Global Navigation Satellite System (GNSS).
- It can hence be used to simultaneously provide guidance to an unlimited number of aircraft conducting concurrent approaches at multiple locations.
About GAGAN
- GAGAN is an acronym for GPS Aided GEO Augmented Navigation.
- It is a Space Based Augmentation System (SBAS) jointly developed by ISRO and AAI.
- The aim is to provide the best possible navigational services over Indian FIR (Flight Information Region) with the capability of expanding to neighboring FIRs.
- The system is interoperable with other international SBAS systems like US-WAAS, European EGNOS, and Japanese MSAS, etc.
- GAGAN GEO\’s footprint extends from Africa to Australia and has expansion capability for seamless navigation services across the region.
Working of GAGAN?
- GAGAN is a system of satellites and ground stations that provide GPS signal corrections, giving you better position accuracy.
- GAGAN consists of a set of ground reference stations positioned across various locations in India called the Indian Reference Station (INRES), which gathers GPS satellite data.
- A master station, the Indian Master Control Centre (INMCC) collects data from reference stations and creates GPS correction messages.
- The corrected differential messages are uplinked via the Indian Uplink Station (INLUS).
- Then broadcasted on a signal from three geostationary satellites (GSAT-8, GSAT-10, and GSAT-15).
- The information on this signal is compatible with basic GPS signal structure, which means any SBAS-enabled GPS receiver can read this signal.
- The GAGAN system provides a Non-precision approach (NPA) service accurate to within the radius of 1/10th of a nautical mile.