Middle East Augmentation System - Research Paper Example

Middle East Augmentation System Executive Summary Augmentation system is a system that develops the accuracy of the GPS satellitenavigation system and provides improvements in aircraft performance or pilot handling characteristics over that of the basic un-augmented aircraft. America uses the wide area augmentation system (WAAS) as an air navigation aid developed by the Federal Aviation Administration (FAA). The main purpose of using it is to augment the Global Positioning System (GPS), with the goal of improving its three main dimensions, which are accuracy, integrity, and availability. Augmentation system is used to enable aircraft to rely on GPS for all phases of flight, including precision approaches to any airport within its coverage area. On the other hand, Europe has the European GNSS overlay system (EGNOS). India is launching its GPS-aided Geo-augmented navigation (GAGAN) system; however, Japan has the multifunction satellite augmentation system (MSAS). They are all satellite-based augmentation systems (SBAS) and are already delivering improved accuracy and integrity for GPS users over much of the northern hemisphere. Since we do not have augmentation system in the Middle East, we came with new idea of creating Middle East wide augmentation system (MEWAS). The system of satellites and ground stations, which will give GPS signal corrections for errors, caused by ionosphere disturbances, timing, and satellite orbit errors. In this report, we will present our new idea Middle East wide augmentation system Space and Ground Segments as an integration part of Global Satellite Augmentation System (GSAS) for enhanced Traffic Control and Management (TCM) globally at sea, on the ground (road and railway vehicles) and in the air. We will discuss how it works. Beside of that, we will look for some benefits, limitations and the future of Middle East wide augmentation system (MEWAS). The purpose of this document is introducing in details (MEWAS) system, which will make flying more efficient and safe for users. Contents Executive Summary 2 Contents 3 Introduction 4 Overview of the project 7 ASAS 9 ASAS benefits 11 How it Works 13 Coverage of the geostationary satellites 15 The benefits of Middle East Wide Augmentation System (MEWAS) 16 Conclusion 17 References 19 Introduction GPS is a global positioning, navigation, and timing network consisting of space, ground control, and user equipment segments that support the broadcasts of military and civil GPS signals. These signals each include positioning and timing information, which enables users with GPS receivers to determine their position and time, 24 hours a day, worldwide. All branches of the military to guide troops’ movements, integrated logistics support and battle space situational awareness, and communications network synchronization use GPS. In addition, bombs and missiles are guided to their targets by GPS signals and GPS is used to locate military personnel in distress. Early in the development of GPS, the scope was expanded to include complementary civil capabilities. In demanding environments where accuracy and integrity are required, GPS and global navigation satellite system (GNSS) can be greatly enhanced by the use of augmentation information derived from various sources. Augmentation system and GPS work together to meet normal consumers’ navigational requirements by making flying more efficient and safe for users. They use a network of ground-based reference stations to measure small variations in the GPS satellites signals. Measurements from the reference stations are routed to master stations, which queue the received Deviation Correction (DC) and send the correction messages to geostationary satellites every 5 seconds. Those satellites broadcast the correction messages back to Earth, where WAAS-enabled GPS receivers use the corrections while computing their positions to improve accuracy. a. Background It is no surprise that WAAS, EGNOS and MSAS have not been developed to increase the accuracy of GPS for hikers and geocaches. The Wide Area Augmentation System (WAAS) is being developed by the Federal Aviation Administration (FAA) to augment the Global Positioning System (GPS). WAAS, a satellite-based augmentation system operated by the Federal Aviation Administration (FAA), supports aircraft navigation across North America. The earliest generations of the GNSS (global satellite system) are depicted by old primary solutions for PVT. PVT represents position, velocity, and time of navigation by satellite and systems, which are used for determination such as GLONASS and GPS for the Russian and US military requirement. The GLONASS and GPS are the infrastructures, which give positions of about thirty meters. They are the first generation of GNSS-1. They suffer from various weaknesses because they use simple GPS receivers, which are onboard aircraft or ships. This defect makes them unreliable for aviation and land applications. Recent development of augmented GNSS-1 solutions were meant to correct the aforementioned disadvantages of present military systems in addition to meeting the necessary civilian transportation requirements for high operating ICAA( integrity, continuity, accuracy, and availability). These solutions include WAAS for North America. The solutions for the Middle East are Japanese MTSAT’s MSAS, Indian GPS/GLONASS and GEOS augmented navigation (GAGAN), the Chinese SNAS, Russian SDCM, and ASAS. The multi-functional satellite augmentation system (MSAS) is an augmentation system relying on satellites. It is a system, which backs the differential GPS which is made to act as a supplement to the GPS system. It does this by improving and reporting on the accuracy and reliability of the signals. This system improves accuracy from twenty meters to two meters. GAGAN is an Indian program. India plans to construct its satellite based GPS augmentation system, which will be regional. The primary objective of the program is to close the gap between the European geo stationary navigation overlay system and the Japanese MTSAT space augmentation system (Lechner, 2000). This would aid in the seamless navigation of planes from the east to the west and vice versa. The EGNOS, WAAS, SNAS, MSAS GPS augmentation systems link up the gap between the needs of the civil aviation industry and the GPS military applications. These Europe, Asia, and USA systems comprise of or are composed of a group of differential GPS ground stations. They utilize the Inmarsat 3 geo synchronous satellite. This constellation acts as a way of conveying the differential corrections to its users. GPS time is recorded throught the Inmarsat 3 downlink/uplink networks in the act of conveying accurate navigation signals. This functionality supports the robust retrieval for frequency synchronization and time needs of the telecommunication industry. The SNAS, SDCM, MSAS, ASAS, and GAGAN are satellite based augmentation systems (SBAS) which cover all or part of the Middle East. All the mentioned Middle East satellite based augmentation systems use corrective signals or additional satellites to make the GPS signal correct. Lack of the corrective signals will make the GPS less accurate. b. The objectives of Middle East Wide Augmentation System (MEWAS) In our project, we aim to create a special and efficient mechanism for the augmentation system that will support various places in the Middle East. Particularly, it should help in achieving the following: Increased accuracy, integrity, reliability, and availability of information for aviation and navigation system.  Make MEWAS available on the Web in real time over the Internet to provide uninterrupted availability of positioning, navigation, and timing services. Continue to provide civil services that exceed or are competitive with foreign civil space-based positioning, navigation and timing services and augmentation systems. Overview of the project The GNSS-1 characteristics and elements which are standardized by the board (ICAO) that aid in complimenting the GLONASS or GPS augmented system are two. Regional RSAS project is the first element. The RSAS (regional satellite augmentation system) will replace the SBAS (satellite based augmentation system) for better convenient nomenclature. GEO Satellite diffuses the complimentary RSAS information through the use of a pseudo GLONASS or GPS signals and it covers a large area geographically of GSAS systems, for example, the ASAS project for the Middle East region and the whole African continent. Second is the Local LSAS project. The LSAS (local satellite augmentation system) nomenclature is better than GBAS (ground based augmentation system) of ICAO. The supporting information is basically valid over a small area, for example, at the airport and seaport. They can utilize satellite diffusion to enable connection between TCC and mobiles. The local scene can also use LVAS in similar circumstances and diffused using VHF radio system. This system is the same as the US DGPS. Using this basis, the TAB group or team will launch the design n creation of the regional ASAS. The primary objective of this program is to provide one navigation system that will cover the whole of the Middle East. The program (ASAS) will or is a combination of both space and ground facilities to augment the GLONASS or GPS standard positioning service. The ASAS is designed as the next generation aviation, land and civil maritime CNS services. However, the primary objective of ASAS is to provide a fundamental way of better land, maritime and aeronautical application navigation. The RSAS mission will provide the following functions; integrity monitoring which will ensure that errors indicated will range in between the allowed limits coupled with a high probability hence ensuring safety. Secondly, the DGPS corrections will lead to improvement of accuracy. Lastly, ranging will help in improving availability. As a result, corrections, which are separate and differential, will be broadcasted by the RSAS to rectify the GLONASS or GPS satellite ionospheric, ephemeris and clock errors. The ionospheric corrections will broadcast select IGP (ionospheric grid points) at this point. These are lattice points of a grid of lines representing a never changing longitude and latitude at the ionosphers’s height. The ASAS network, or leased Artemis GNSS and Inmarsat 3 satellite payloads will integrate the space segment developed by the government of South Africa. This is in addition to the ground segment. It includes primary and secondary GCS, GMS, GES, and TCC (traffic control center) to achieve improved integrity, accuracy, and availability past the standard GLONASS or GPS constellations. The IS Marine radio, TAB team with partnerships from Ukraine, Leica, Russia and research institutions like NSI (national space institute) coupled with DST( south African department of science and technology) will do the research and feasibility studies for the design and development of the regional ASAS prototype. Additionally, they will participate in the experimental tests of the ASAS. The TAB team analyzes the experimental system’s accuracy when it will be utilized in guiding ships in the Middle East. Feasibility studies include performance tests of other integrity algorithms and ionospheric correction (error bounding). Moreover, TAB helps in establishing ASAS’s performance demands and give data to teams that will aid in evaluating the responses of the contractors designing the ASAS project. This will be in safety and performance areas. All the parties involved in the project are used in the sensitivity analysis to aid in unraveling the location of land resources like GES and GMS and optimal mix. Furthermore, they will determine design change impacts that will affect the location and performance of the equipment. Moreover, it will highlight the behavior of a space navigation system to air traffic planners, for example, the orbiting sensors. Lastly, it will aid in the determination of operational strategies in handling areas experiencing low performance. ASAS The ASAS system is designed and developed to be the primary way of satellite CNS for the aviation routes in the Middle East region and the African continent. It will be used to regulate planes approaching the airports in the region in addition to regulating the movement of vehicles and planes on the surface of airports. This way, the ASAS will be used in the maritime operations like navigation at close and open seas, ocean crossings, passages, and channels, coastal navigation, approaching to ports and anchorages, land (railway and road) applications and inside of ports. The TAB team initiated a three phase developmental approach in completing the network (ASAS) as following : Phase 1 was between 2011 and 2012. The phase commenced with ASAS commissioned 5GCS uplinks, three leased GEO satellites, 5GES and 44 GMS. The GMS infrastructure was upgraded to 55 and given its own satellites. This system will boost category 1PA but within a small coverage area. The ground network (ASAS) will boost coastal navigation and civilian maritime deep-sea navigation. This includes ships approaching seaports and anchorages. The land application will make accurate navigation facilities for rail and road vehicles possible. The aeronautical application will enable NPA, mobile terminal navigation and en route navigation. Phase 2 of the project commenced in 2012 and will end in 2015. This phase initiated with full ASAS facilities. The GMS were added up to 55. The initial redundant ASAS operational coverage restrictions will be removed. ALAS ground facilities will be deployed in the Middle East’s major airports and seaports. Accurately surveyed stations on the ground containing multiple processors and GPS receivers are established at all airport runaway ends. A lighting system will be provided as an additional infrastructure. The reduction of NAV AIDS which are ground based facilities, for example, NDB (non-directional beacons) and VOR are initiated during this phase. ICAA and GPS strength will be bolstered by the addition of the second and third civil radio frequencies. Phase three of the project will commence in 2015 and cease in 2018. This phase will enhance the reduction of NAV AIDS, which are ground based. The DME and VOR will prop operations only at fundamental air routes. It will also support NPA at many airports. The ILS will prop PA at airports, which are very busy for management and ATC. This stage will see the modification of full constellations of GLONASS and GPS with second and third civil frequency band, which is available for ALAS /ASAS. They will be modified to dual frequency avionics to avoid unintentional jamming. All airport NAVAIDS (NDB, VOR) will be completely phased out during this period. ASAS benefits The ASAS program provides the following services; First, the relaying of health and integrity data in real time on every GLONASS and GPS satellite. This enables information users to avoid using satellites, which are faulty for navigation, called the GNSS integrity channel (GIC). Secondly, the ASAS program supplements the GPS through continuously transmitting ranging signals combined with the GIC service. This leads to the availability of the GLONASS or GPS signal. RAIM (receiver autonomous integrity monitoring) increases with the increase in the availability of the signal. This is referred to as ranging GIC (RGIC). Thirdly, civil GLONASS and GPS signal accuracy is increased greatly. This feature is often referred to as WADGNSS (wide area differential GNSS). This accuracy is because of relay of GLONASS or GPS wide area differential corrections. The ASAS network is a combination of Artemis spacecraft and Inmarsat overlay services. All users of mobiles get signals from GLONASS satellites or GNSS-1 of GPS. GNSS-2 signals from the compass and Galileo satellites will be used in the near future. All GMS integrity monitoring network terminals receive these signals. These networks are run by the various government agencies in the Middle East and Africa. The data, which has been monitored, is forwarded to the each region’s integrity and processing facility of GCS. Here, the data is processed and converted into WADGNSS correction messages. These are the sent to the primary GNSS GES. The signals are synchronized accurately here to a reference time and the modulated with the WADGNSS corrections and GIC message data. The signals are transferred to a satellite via GNSS payload which is found in Artemis spacecraft and Inmarsat GEO and then on the downlink c band to mobile users. Through the same l band downlink and spacecraft, users are able to forward augmented CNS data. CNSS data, which is received by from the mobile users, is being processed by TCC sites and shown on the surveillance screen. This illustrates their accurate locations and in real time. As such, the ASAS is primarily used as navigation means during every traveling phase of each mobile application in the Middle East and Africa. The ASAS program can basically be said to be made up of 24 GLONASS satellites, 24 operational GPS, one Artemis and two Inmarsat GEO satellites. By utilizing a modulation that is similar to the one used by GPS, the GEO satellites downlink data to users on the GPSL1 RF. Information in the navigational message, when processed by an ASAS Rx, allows the GEO satellites to be used as additional GPS-like satellites, thus increasing the availability of the satellite constellation. At this point, the ASAS signal resembles a GPS signal origination from the Gold Code family of 1023 possible codes (19 signals from PRN 120-138). A ground segment of the ASAS includes a network of specific GMS cities that survey the signals originating from the satellites and sending the information to more or one GCS, which then comes up with the augmentation message of a region in the Middle East. Actually, the signal of ASAS is modulated with a 250 b/s data message, which possesses the ionospheric mapping terms, vector position correction, and health information. This data distinguishes the ASAS program from other normal GLONASS or GPS by increasing satellite health, enhancing the availability, improving health of the system. It therefore, improves accuracy and reduces errors by adding new ranging signals and by reduction of the range measurement error. ASAS limitations ASAS has a few limitations, they include: 1. Automated tasks cannot be performed by ASAS since the technology is unavailable or incompatible. 2. ASAS is easily influenced by environmental conditions in addition to depending on electrical power. How it Works An augmentation system uses earth stations that have been very carefully surveyed, and their exact locations are known with great precision. As they receive signals from the GPS satellites, they are compared with the values they should be receiving, and the differences are used to calculate corrections. The corrections are transmitted either to the GPS receivers via geostationary satellites or terrestrial radio. The WAAS uses 25 ground-based stations across America to monitor satellites. There are two Wide Area Master Stations and 23 Wide Area Reference Stations. WAAS is different from other navigation systems in the world. It covers almost all the National Airspace System (NAS). The WAAS provides Augmentation information to GPS receivers to enhance the accuracy and reliability of position estimates. The signals from GPS satellites are received across the NAS at many widely spaced Wide Area Reference Stations (WRS) sites. The WRS locations are precisely surveyed so that any errors in the received GPS signals can be detected. The GPS information collected by the WRS sites is forwarded to the WAAS Master Station (WMS) by a terrestrial communications network. At the WMS, the WAAS augmentation messages are generated. These messages contain information that allows GPS receivers to remove errors in the GPS signal, allowing for a significant increase in location accuracy and reliability. The augmentation messages are sent from the WMS to uplink stations to be transmitted to navigation payloads on geostationary communications satellites The navigation payloads broadcast the augmentation messages on a GPS-like signal. The GPS/WAAS receiver processes the WAAS augmentation message as part of estimating position. The GPS-like signal from the navigation transponder can also be used by the receiver as an additional source for calculation of the user’s position. WAAS also provides indications to GPS/WAAS receivers of where the GPS system is unusable due to system errors or other effects. Further, the WAAS system was designed to the strictest of safety standards – users are notified within six seconds of any issuance of hazardously misleading information that would cause an error in the GPS position estimate. Coverage of the geostationary satellites The following table lists the WAAS/EGNOS satellites and their identification numbers: Satellite Satellite location GPS PRN No. Garmin Sat ID INMARSAT 3 F2 (AOR-E) (Atlantic Ocean Region East) Western Africa 120 33 INMARSAT 3 F1 (IOR) (Indian Ocean Region) Indian Ocean 131 44 INMARSAT 3 F4 (AOR-W) (Atlantic Ocean Region West) East coast of Brazil 122 35 INMARSAT 3 F3 (POR) (Pacific Ocean Region) Pacific 134 47 INMARSAT IOR-W (III-F5) (Indian Ocean Region West) Africa (Congo) 126 39 Artemis Africa (Congo) 124 37 MTSAT-1R (Multifunction Transportation Satellite) planned 129 42 MTSAT-2 planned 137 50 The benefits of Middle East Wide Augmentation System (MEWAS) The main purpose of creating MEWAS is to increase safety for aviation. This will happen by improving the accuracy, integrity, reliability, and availability of GPS. MEWAS will increases the navigation capability for all classes of aircraft in all phases of flight. Beside of that, the following benefits will be achieved: Reduced separation standards, which allow increased capacity in a given airspace without increased risk. More direct en route flight paths because MEWAS works just as well between airports, which will allow the aircraft to fly directly from one airport to another, as opposed to following routes based on ground-based signals. Reduced and simplified equipment on board aircraft. Significant government cost savings due to the elimination of maintenance costs associated with older, expensive ground-based navigation aids. This ability to self-detect system position errors will allow the flight crew to be notified in a timely fashion of the error, much like a flag on a VHF navigation radio. Conclusion The concept of our project is augmentation system in the Middle East Wide augmentation System call MEWAS. Middle East Wide Augmentation System(MEWAS) will provides services for all classes of aircraft in all phases of flight - including en route navigation, airport departures, and airport arrivals. The ASAS network covers the Middle East and the African continent. The space and ground segments of the ASAS network are part of an ongoing process of integration of GSAS (global satellite augmentation system). This helps in the enhancement of traffic control and management in the air, land, and sea in the Middle East region. This network can be solely used to provide and cover TCM, security and safety for the Middle East region. This is according to GMDSS (global maritime distress and safety system, ICA (international civil aviation organization, and IMO (international maritime organization) requirements. The ASAS has passed all the safety requirements enforced by the various bodies. In the Middle East region, the present traffic control and radios are based on technology from the 1960s. Ocean seas lack radar coverage in the Middle East region. As a result, aircraft pilots and captains have to report their verbally their positions by voice. The new ASAS system of GSAS will improve the accuracy of the GLONASS and GPS signals from a range of about thirty meters to nearly three meters in the Middle East region. The WAAS system in the United States gives two to three meters accuracy vertically and an accuracy of one to two meters horizontally through the United States. Unfortunately, a GLONASS or GPS receiver must be upgraded by software or hardware module to be able to receive and decode the signals emanating from the ASAS network. It will be possible in the future to integrate into the ASAS network new satellite systems like the Inmarsat 4. This will increase the accuracy in the augmentation of the Middle East. References Lechner, W., & Baumann, S. (2000). Global navigation satellite systems. Computers and Electronics in Agriculture, 25(1), 67-85. United Nations (2012). Global Navigation Satellite Systems. Retrieved from http://www.oosa.unvienna.org/pdf/icg/2013/Ed_GNSS_eBook.pdf Read More