Sample Aviation Research Paper on RNAV and ADS-B

Area Navigation is a generic name for systems that allow navigation over wide areas (Advanced avionics handbook, 2012). The name was originally coined for a way of electronically moving navaids, to other places enroute, which implies that you must be within the operating range of the navaids concerned (advanced avionics handbook, 2012). RNAV facilitates aircraft navigation along any desired flight path within range of navigation aids. A flight path can also be planned with independent navigation equipment. Optimum area navigation is achieved using a combination of ground navigation aids and independent equipment.

Typical navigation sensor inputs to an RNAV system can be from external ground-based navigation aids such as VHF omni-range (VOR) and distance measuring equipment (DME) (Clausing, 2007). Independent systems include global satellite navigation or inertial reference system (IRS) (Calusing, 2007). Many RNAV systems use a combination of numerous ground-based navigation aids, satellite navigation systems. RNAV is an increasingly popular method of navigation that allows pilots to make more efficient use of the national airspace system. RNAV is not solely dependent on satellite navigation systems. In addition to using self-contained methods such as inertial navigation systems, it may also be accomplished by using ground based navaids such as DME.  RNAV  allows the navigation of aircrafts between any two points. RNAV defines locations in terms of longitude and latitude and then categorized as a waypoint. 

RNAV systems can store many waypoints in a sequence that comprises a complete route. RNAV can allow new variations on the standard precision/non-precision approach theme, using waypoint patterns that eliminate procedure turns because there is no dependence on the location of ground-based aids. Lower minima and increased capacity are also available.

The components of RNAV include the off/on/volume control, Mode, RNAV mode, RNAV/APPR, Data input controls and WP select control. The Off/On/Volume controls are use to select the frequency of the VOR/DME station to be used. Mode is used to select VOR/DME mode with angular course width deviation or linear cross-track deviation as standard. RNAV (Clausing 2007) mode has a direct to WP with linear cross-track deviation of ±5 NM. Some units allow the storage of more than one waypoint and the waypoint select control allows the selection of any waypoint in storage. Data input controls allow the use r to input waypoint number or ident. Every avionics device has a display and a collection of buttons and keys and knobs used to operate the unit. The display allows the device to present information. The controls allow the pilot to enter information and program the avionics to accomplish the desired operations or tasks.

With RNAV, more efficient, flexible and directs routes that account for pressure altitude and wind are generated. Pilots using the RNAV system arrive faster at their destination because the RNAV system has more direct routes especially for shorter flights (Clausing, 2007). The RNAV system bypasses routes to overfly high-density terminal areas and creates alternative or contingency routes. Finally, the RNAV system provides  improved locations for holding patterns. However, the system has its shortcomings which include but not limited to: possible way to obtain wrong waypoints from ground stations and same errors occur as in DME, VORTAC and VOR systems.

            Automatic Dependent Surveillance-Broadcast (ADS-B) is a function enabling aircraft, irrespective of whether they are airborne or on the ground, and other relevant airport surface traffic, to periodically transmit their horizontal and vertical position, and horizontal and vertical velocity (Duan, 2011). ADS-B also transmits other surveillance information for use by other traffic in the vicinity or users on the ground, such as Air Traffic Control or the air line. This surveillance information which is dependent on data obtained from various onboard data sources, such as the air data or navigation system is broadcast automatically and does not require any pilot action or external stimulus. Similarly, the aircraft or vehicle originating the broadcast does not receive any feedback on whether other users within range of this broadcast, either aircraft or ground-based, decode and process the ADS-B surveillance information or not.

            ADS-B was conceived to support improved use of airspace, reduced ceiling and visibility restrictions, improved surface surveillance and enhanced safety.  ADS-B is an emerging air traffic surveillance technology that enables the suitably equipped aircraft and airport ground vehicles to be tracked by air controllers without need for conventional radar and by pilots of other aircraft that are equipped with ADS-B receive equipment. ADS-B traffic surveillance information transmitted by other aircraft and airport ground vehicles is referred to as ADS-B out and is expected to replace radar as the primary source of traffic surveillance used by air traffic controllers to control traffic world wide. ADS-B will enable a broad range of on-aircraft application that is referred to as ADS-B IN to allow pilots safely and efficiently operate their aircraft at reduced distances form other traffic.

            ADS-B is an integral system in plans for upgrading the aviation infrastructure around the world to support enhanced aircraft operations. In the United States, ADS-B plays a vital role in the Federal Aviation administration plan to overhaul the National Airspace air Transportation system which is referred to as NextGen (Duan, 2011). Similarly in Europe, ADS-B is viewed as an integral system to enable the Single European Sky Traffic Management Research initiatives for improving the air transportation system.

            More accurate than radar, ADS-B systems determine their own surveillance information very precisely using global navigation satellite receivers installed on the aircraft or vehicle with a more understanding of the location of aircraft and operationally relevant airport ground vehicles, the air transportation can be designed to make better use of the airspace. ADS-B is a lower-cost technology that radar and it enables both pilot and air traffic controllers to see and control aircraft with more precision over a far larger portion of the Earth than has ever been possible before (Duan 2011).

The ADS-B has four features that support its function. The automatic feature transmits surveillance information automatically without interrogation. The Dependent feature depends on equipped aircraft/vehicles to cooperatively self-report their surveillance information relying on the availability of a suitable onboard position source such as a GNSS receiver (Helfrick, 2009). The surveillance feature provides surveillance information for accurate aircraft tracking to air traffic controllers and other users. Finally, the broadcast feature broadcast aircraft position and other data to all aircraft and ground stations equipped to receive ADS-B simultaneously.

            ADS-B uses two fundamental components to support its operation including GNSS to determine position and velocity, and a broadcast communication link to share the surveillance information with other users. ADS-B creates and listens for periodic surveillance reports from aircraft that are updated every second. As a result, ADS-B surveillance data is better than radar since position is much accurate.

References

Advanced Avionics Handbook: Faa-h-8083-6. New York, NY: Skyhorse Pub, 2012. Print.

Clausing, D. J. (2007). The aviator’s guide to navigation. New York: McGraw-Hill.

Duan, Pengfei. Automatic Dependent Surveillance-Broadcast (ads-B) Space-Oriented Message          Set Design. Ohio: Ohio University, 2011. Internet resource.

Helfrick, A. D. (2009). Principles of avionics. Leesburg, VA: Avionics Communications, Inc.