JP2013044576A - Agps server having sbas support information for receiver of artificial satellite base - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable navigation receivers provided with information of a satellite-based augmentation system (SBAS) visible from a specific ground surface position to intelligently search, capture and track pseudo random number (PRN) signals of SBAS satellites visible from them.SOLUTION: An artificial satellite navigation system support server is configured to respond to a request of a client including display of a client position. When an accurate position is included in a server request, an artificial satellite navigation system support server computes which specific SBAS system can be observed from the requesting client. In this case, the artificial satellite navigation system support server limits the response to related information for a more compact response message.

Description

  The present invention relates to satellite navigation systems, and more particularly to worldwide observation reference points for compiling a list of geostationary satellite augmentation systems (SBAS) visible from a particular surface location, resulting in network A navigation receiver provided with this information from the server can intelligently search, capture, and track SBAS satellite pseudo-random number (PRN) signals visible from them.

  The Wide Area Augmentation System (WAAS) is an air navigation assistance developed by the Federal Aviation Administration to supplement the Global Positioning System (GPS). Its goal is to improve the accuracy, completeness, and availability of GPS. WAAS is planned to make the aircraft dependent on GPS for precision approach and other flight stages. WAAS uses a network of ground observation reference points that have been accurately surveyed in North America and Hawaii to detect GPS surface transmission errors in various regions. The measured value is transferred to the main station for each region. Deviation correction (DC) is sent in a correction message to the geostationary WAAS satellite at least every 5 seconds. The geostationary WAAS satellites then broadcast correction messages back to North America and Hawaii so that WAAS-enabled GPS receivers can include the corrections in their navigation position calculations. WAAS does not provide services to Europe or Asia. This is because geostationary WAAS satellites are not visible from there, and the measurements obtained are not applicable there.

  The International Civil Aviation Organization (ICAO) refers to WAAS as a geostationary satellite augmentation system (SBAS). Europe and Asia have corresponding SBAS deployments (ie, satellite navigation augmentation service (EGNOS) with geostationary satellites in Europe, geostationary satellites for air traffic control around India (GAGAN)), and satellite navigation augmentation systems for Japanese multipurpose satellites (MSAS)). Commercial SBAS operations include StarFire and OmniSTAR. These have geostationary satellites that stay on their service area. Therefore, no place on the earth can see WAAS, EGNOS, GAGAN, MSAS, and other satellites simultaneously.

  The position accuracy of WAAS should be better than 7.6 m (25 feet) for horizontal and vertical measurements (at least 95% of WAAS usage time). Tests have shown that most regions in North America typically provide good solution accuracy of over 1 meter (3 feet 3 inches) in the horizontal direction and 1.5 meters (4 feet 11 inches) in the vertical direction. Yes. Therefore, WAAS satisfies Category I, which requires a precision approach accuracy of 16 m (52 ft) in the horizontal direction and 4 m (13.1 ft) in the vertical direction.

Maintaining the integrity of the navigation system requires timely warnings when data is provided that can be dangerous and misleading. The WAAS specification requires that the system monitor and detect errors in GPS and WAAS networks and notify the user within 6.2 seconds. Proving that WAAS is safe for instrument flight (IFR) requires proof that any error that exceeds the accuracy requirement will be found. Specifically, the probability is described as 1 × 10 ⁻⁷ and is equal to defective data of less than 3 seconds per year. This provides integrity information that is equivalent to or better than Receiver Autonomous Integrity Monitoring (RAIM).

  The WAAS ground segment contains several Wide Area Reference Stations (WRS) with precisely surveyed locations that monitor and collect information about GPS signals and Send to 3 wide area main stations (WMS) using the base communication network. The observation reference point also monitors signals from WAAS geostationary satellites and provides completeness information about them as well. As of October 2007, there were 38 WRS. 20 of these are in the US mainland (CONUS), 7 in Alaska, 1 in Hawaii, 1 in Puerto Rico, 5 in Mexico, and 4 in Canada.

  Data from the WRS site is used by each WMS to generate a fast correction set and a slow correction set. Fast correction is for rapidly changing errors and is primarily related to the instantaneous position and clock error of GPS satellites. These corrections are independent of the user location and can be applied immediately by the receiver in the WAAS broadcast area. Slow correction relates to long-term ephemeris and clock error estimates, as well as delay information in the ionosphere. Delay correction is provided for points organized in a grid pattern across the WAAS service area. Each WMS sends a correction message to the geostationary satellite in the space segment through an extra ground uplink station (GUS) and rebroadcasts to the user segment.

The WAAS space segment has a number of geostationary communication satellites that broadcast correction messages from wide area main stations for reception by the user segment. Each of them also broadcasts distance information like GPS satellites, effectively increasing the number of satellites available for position fix. Originally, the space segment had two commercial satellites: the Pacific region (POR) and the Atlantic region (AOR-W). These are actually universes leased by Inmarsat III satellites, which stopped the WAAS transmission on July 31, 2007. Two new satellites (Galaxy 15 and Anik F1R) were launched at the end of 2005. Galaxy 15 is PanAmSat and Anik F1R is Telesat. These are leasing services under the FAA (Federal Aviation Administration) geostationary satellite communications control segment that signed with Lockheed Martin for WAAS geostationary satellite leasing services. Lockheed Martin has contracted to provide up to three satellites by 2016. Distance data from Galaxy 15 and Anik F1R is flagged as “Precision Approach”.

  The first challenge of the SBAS receiver is to collect the PRN mask. The receiver needs this before the SBAS message is available. Collecting PRN masks can take up to 1 minute. After receiving the PRN mask, the SBAS receiver must determine the proper satellite health and differential GPS correction to use. The ephemeris is necessary to get the distance and include the SBAS satellite in the fix. However, obtaining ephemeris has a lower priority than obtaining satellite health and differential GPS correction. Thus, autonomous SBAS receivers generally do not have SBAS data available before the first fix is possible. The initial fix may not be very accurate and does not extend to at least the usual SBAS-assisted navigation receivers.

  Galileo is a global satellite navigation system (GNSS) that is under construction by the European Union (EU) and its European Space Agency (ESA). It overlaps with the United States Global Positioning System (GPS) and the comparable Russian system (ie GLONASS). Galileo is expected to be available by 2014 at two ground operations centers, one near Munich, Germany and the other, just east of Rome, Italy. Galileo is planned to make more accurate measurements available (especially at high latitudes) rather than being widely accessible with GPS or GLONASS. Since Russia and the United States both have military options to switch on signal encryption, their political goal is to provide an independent positioning system that European nations can rely on. The basic Galileo service is to be open to everyone for free, but its high-precision capabilities are limited to EU military users and commercial subscribers.

  Briefly, the satellite navigation system support server embodiment of the present invention is configured to respond to client requests. The request includes an indication of the client location, and if the exact location is included in the server request, the satellite navigation system support server can observe which particular SBAS system the requesting client is In this case, the satellite navigation system support server limits the response to related information for a more compact response message. The quality of the SBAS assistance that can be returned depends on how accurately the client estimated their position in the request message. A very accurate estimate is in return for a very detailed SBAS support. A rough estimate can only be larger or result in worldwide SBAS support.

DETAILED DESCRIPTION OF THE INVENTION Other objects and advantages will no doubt become apparent to those skilled in the art after reading the following detailed description of the preferred embodiment illustrated in the various drawings.
It is a functional block diagram of the configuration of the SBAS of the present invention and an embodiment of the system. It is a functional block diagram of a satellite navigation system support server in an embodiment of the present invention.

  FIG. 1 shows an SBAS configuration 100 in an embodiment of the present invention. A number of clients 101-104 comprise satellite navigation receivers that provide their users with location, velocity, and time information (PVT) based on microwave signals, which are client receivers (e.g., WAAS 111, EGNOS 112, MSAS 113, GAGAN 114, StarFire 115, OmniSTAR 116) corresponding to the positions of GPS satellites 106, GLONASS satellites 108 and local SBAS systems in the orbit. The SBAS systems 111-116 all track and analyze satellite transmissions from the US Nabster GPS and the Russian GLONASS navigation system. The European Galileo navigation system will also be included when it becomes available.

  The individual satellite vehicles (SV) are matched or made different from each other by the microwave receiver depending on the specific code division multiple access (CDMA) pseudo-random number (PRN) code that they modulate their signals. The PRN mask message contains a mapping of corrections provided by SBAS to a list of 210 possible pseudorandom signal (PRN) sequences, including all of GPS, GLONASS, future GNSS, and SBAS satellites themselves. Yes. For example, if GPS PRN1 is not launched and PRN2 is launched, the PRN mask for that situation is 0 for the enable bit in bit position-1 and for the enable bit in bit position-2. 1

  And the very first correction message corresponds to GPS PRN2. The PRN mask is a table of launched satellites that can be quickly examined to determine which PRNs are allowed and which are excluded from the search for receiver signals. Notifying the initializing navigation receiver about which SV is in the air at any moment means that no time is wasted on obtaining the SV. Only the corresponding PRN should be searched. This, of course, requires that the receiver should have a fairly good starting point in terms of where and when. And almanacs are useful as a reference to indicate which SVs, and their PRNs will be empty at various times and places. However, the main purpose of the PRN mask is to map individual corrections in the SBAS data stream to a specific PRN of a specific GNSS.

  Corresponding SBAS receivers 121-126 are strategically located throughout the world to receive regional transmissions from each of the SBAS systems 111-116 (eg, North America, Asia, and Europe). Each SBAS system has at least one geostationary satellite. Each SBAS receiver 121-126 reports both SBAS data and navigation system satellite data (GPS and GLONASS) to the Internet server 130. The PRN adjustment processor 132 reconciles the data because it is very likely that a navigation satellite in a particular orbit will be visible to multiple SBAS systems 111-116 simultaneously. All results for all satellites, including SBAS geostationary satellites, are stored in the satellite PRN database 134.

  Information stored in the satellite database 134 is sent by the clients 101-104 compared to attempting to download the corresponding SBAS transmission directly from the WAAS 111, EGNOS 112, MSAS 113, GAGAN 114, StarFire 115, or OmniSTAR 116. It can usually be obtained more quickly through the Internet at the time of its activation. Server 130 can send the appropriate SBAS data to clients 101-104 in a short message, or all the SBAS data it has in a much longer message. In some situations, clients 101-104 may not have the internet connection bandwidth necessary to receive longer SBAS messages. Thus, if clients 101-104 send their coarse location to server 130, the server will have a PRN mask, independently estimated satellite health, differential GPS, and SBAS limited to the immediate needs of a particular client. Ephemeris and almanac information can be returned. The server must also send the appropriate PRN mask for each SBAS system. Each SBAS system is maintained independently, and any two SBAS systems may not always be the same in this regard. Therefore, the PRN mask for each system must be communicated. Even if changes between launched GNSS satellites are very rare, the SBAS system may treat new and old satellites differently.

  Regardless of actually measuring the phase or frequency of the satellite based on the data it collects, the server 130 can provide global health information for each and every GPS / SBAS satellite. Clients 101-104 do not use signals from unhealthy or high error satellites. The server provides DGPS correction values to all satellites in a message that each client can use before actually starting to track SBAS satellites. These can be used as initial DGPS correction values before receiving data directly from SBAS. Lower accuracy DGPS correction values are used for approximate locations. If the client 101-104 provides an accurate location, a highly accurate DGPS correction value is returned. Server 130 computes the ionospheric delay at the exact location provided by clients 101-104. Visible SBAS satellite ephemeris and / or almanac, as well as their corresponding PRN masks (maps of PRNs to index the provided correction values) are provided depending on the estimated position provided be able to. This is very reliable if the position of the receiver is known, but not so reliable if it is just an approximation. The client can quickly negotiate with the server as soon as it obtains a reliable position fix to get the most accurate and most recent correction value.

  The server 130 sorts and changes its response to each client request according to the quality of client location information that the client provides in their request according to the estimated position error represented by the standard deviation of the position error (position sigma). Let The better the client position estimate, the smaller the position sigma, and the support of the server 130 can be more accurate. If the client receiver has the correct location, the server 130 can vary significantly between observable SBAS systems and responds with just relevant information that constitutes a more compact message format.

  In autonomous mode, the first challenge of the client receiver is to fetch the appropriate PRN mask, so that an available SBAS message can be used subsequently. Collecting a PRN mask can take up to a minute. After receiving the PRN mask, the client receiver must determine the appropriate satellite health and differential GPS corrections to use. The ephemeris is necessary for ranging the SBAS satellite for the calculation of the position fix.

  However, obtaining ephemeris should be a lower priority than obtaining satellite health and differential GPS corrections. This priority is set by the satellite so that the highest priority is providing completeness and correction values, so the ephemeris cycles through the message stream at a less deterministic rate. Autonomous SBAS receivers generally do not make the necessary SBAS data available before the first fix is possible. Using the server 130, the receivers of the clients 101-104 can make use of the SBAS information much faster, and the first fix they each generate is very reliable.

  In an embodiment of the present invention, the initial fix benefits from SBAS integrity checking and correction and is still fast. Its initial fix is faster than a conventional receiver waiting for SBAS information.

  Observation reference points can track all the SBAS satellites they have in view. The difference with respect to SBAS satellites is that they are regional and not well interconnected. In contrast, GPS provides integrity information from a single almanac transmitted by all GPS satellites. The SBAS system is regional or mostly for domestic use only. This is an important issue because PRN masks provided by some SBAS systems are not harmonized. Thus, there may be a long delay from receipt of a correction message that can be used to correct a particular PRN that the client receiver may be tracking.

  Embodiments of the present invention build what becomes the global observation reference point (WWRS) that sorts which PRNs are visible in each area at various times of the day. Each SBAS system sends its own PRN mask that maps an arbitrary index of transmitted DGPS and integrity information to each satellite's specific PRN. Different SBAS systems (eg, WAAS and EGNOS) can send different correction indices for the same PRN.

  As a first step, server 130 includes a method that tells which SBAS PRN to search for at a given location, and provides a PRN mask for the given SBAS PRN (eg, handshake operation). The receiver provides its location and the server responds to that information. This is a significant improvement. This is because without this assistance, the client may have to search as many as 18 SBAS PRNs. Alternatively, since each SBAS satellite is a geostationary satellite, a longitude table can be used to indicate which SBAS PRNs are visible and to which system they belong. For example, for every small angle of longitude, the table shows which SBAS PRN is above the horizon.

  The DGPS correction values and integrity collected from the SBAS receiver are transferred to the GPS receiver. SBAS has a high-speed, low-speed, even spatial correction value, and a complex surface of total electron count (TEC) that enables fairly good ionosphere modeling, into a vector from the receiver to the GPS satellite. It is advantageous in that it is provided on the basis of the corresponding penetration point of the surface.

  Each of the SBAS observation reference point receivers 121-126 can simply be a data collection station (one that does not need to measure phase). The SBAS system has its network of advanced dual frequency observation reference points used to resolve line-of-sight (Los), special and local ionospheric errors.

  One application of embodiments of the present invention is indoor timing where it is not possible to directly receive SBAS broadcasts. Because those broadcasts are too weak.

  SBAS satellites have relatively higher power, but for higher data rates (250 bps encoding using 500 Hz data modulation), with phase alignment greater than 2 ms. It is not possible to obtain a high sensitivity of integration. GPS is about 20 milliseconds, which is only 10 dB sensitive to data collection.

  The main application is for indoor timing, and eRide servers provide ephemeris from GPS RS, as well as integrity and DGPS corrections from SBAS RS and SBAS ephemeris.

  The great advantage of SBAS DGPS and integrity is that it is within 10 seconds. For smaller satellite errors, SBAS provides a spatial DGPS correction, and for larger errors, SBAS declares SV unhealthy. This means much greater completeness using SBAS. For indoor timing, high sensitivity techniques can be used to determine the GPS PRN code phase, but z-count and navData are not determined. The server then provides an ephemeris for usability and a SBAS for DGPS and completeness to enable a robust system.

  Another application for a fast start is to use a server to provide a PRN mask and SBAS ephemeris. Currently this takes about 2 minutes and SBAS data messages are based on priority and do not have a fixed message pattern. The PRN mask is a low priority message, and the integrity and correction values are high priority. Therefore, the time required to obtain the PRN mask and SBAS ephemeris may be long.

  The SBAS ephemeris form is a Cartesian quadratic polynomial in X, Y, Z because SV has an elliptical orbit. It does not have the long persistence of locally more linear GPS ephemeris. The long-term SBAS ephemeris provided to the receiver reduces waiting time and can reduce data traffic because the receiver does not need to request an ephemeris for each session.

  Obtaining a PRN mask delays obtaining a DGPS correction value and completeness because the correction value is sent by an arbitrary index. Thus, providing a PRN mask faster can be speeded up using SBAS, so that SBAS can help the first fix. In general, GPS satellites are available for fix before SBAS satellites are available. This is because a complete GPS model is sent every 30 seconds compared to an SBAS system that sends a rare PRN mask once a minute.

  FIG. 2 shows a satellite navigation system support server 200 in the embodiment of the present invention. The support server 200 includes an Internet presence 202 that is accessible to a client satellite navigation system receiver. It connects to multiple SBAS reference receivers 204-209 located in strategic locations around the world, each of which is an SBAS broadcast from one of the independent SBAS systems 210-215 (eg, WAAS, EGNOS , MSAS and GAGAN) and is configured to receive and process the SBAS broadcast. The SBAS accumulator 220 collects corresponding SBAS messages from multiple SBAS reference receivers 204-209, satellite vehicle (SV) health, DGPS information for GLONASS, GPS, and Galileo SV, and each SBAS satellite The ephemeris and almanac are calculated. PRN processor 222 identifies SVs according to their assigned pseudo-random number (PRN) modulation codes and can be read by specific clients according to the SBAS system visible to their respective locations around the world Collect the superset of the PRN mask The PRN coordination processor 224 coordinates specific PRNs that are replicated between independent SBAS systems 210-215. Correction values and health may differ slightly. Each SBAS system has a different perspective than the location of their particular observation reference point. The PRN database 226 stores information generated by the SBAS accumulator 220, the PRN processor 222, and the PRN adjustment processor 224 according to the corresponding SV PRN.

  The client request processor 228 responds to clients on the Internet that require appropriate SBAS information 232 for SV health, DGPS information, and SBAS ephemeris and almanac, and provides the appropriate PRN mask from the PRN database. If they provide ideas about their current location 230 and require a compact response, the server can only make the volume of SBAS ephemeris and mask information useful.

  In general, servers 130 and 200 are each clients with DGPS corrections and health for any GPS, GLONASS, Galileo, and SBAS satellites based on data received from at least one SBAS observation reference point monitoring at least one SBAS system. Respond to the request. In addition, they provide a global PRN mask (eg, a set of individual PRN masks referenced by the PRN used by the transmitting SBAS satellite). The client can use these PRN masks prior to searching for any SBAS PRN. A table referenced by longitude is provided to inform the client which SBAS PRN is visible and healthy. Clients can then limit their search to SBAS satellites that are visible in the future. The client saves time in getting data messages from unhealthy SBAS satellites.

  Servers 130 and 200 further provide a superset of all SBAS ephemeris so that any satellite can be used quickly for ranging at position fix. Long-term SBAS ephemeris is included so that clients use SBAS for long-range ranging without the need to re-collect ephemeris and often do not request an ephemeris from server 130. This is also useful when the received signal is too weak to obtain data but is strong enough to identify the code phase.

  The amount of SBAS and GNSS information sent can be minimized if the client provides position and error estimates. The server 130 or 200 can then calculate the longitude range (LongMin, LongMax), the appropriate SBAS and GNSS information for visible satellites within such longitude range, the DGPS correction value and health of each satellite. Send a superset of the ephemeris for healthy satellites, and the PRN mask for each SBAS or GNSS PRN visible in that longitude range. In general, the correction value is a short-term value (such as 10 to 30 seconds), while the PRN mask and ephemeris are longer-term values (the PRN mask varies with the launch rate of the satellite, and the ephemeris is about 15 Effective for minutes). In weak signal conditions, only the SBAS code phase is available (if the received SNR is below a reliable decoding level), or if no SBAS signal is available, the client receiver is continuously up to date. High accuracy and integrity can be maintained as before by requiring health and correction values, but ephemeris can be reused for a longer time.

  Clients can save power consumed during search and reduce acquisition time by searching only visible SBAS PRNs. Completeness is improved because the initial and consecutive fixes that cannot track SBAS are always derived from SBAS DGPS and completeness.

  Whenever a DGPS correction value is determined, the server 130 or 200 determines which SBAS system has a better service coverage for a particular SV and prioritizes the DGPS correction value based on that SBAS system. To provide. Which SBAS system is used for the ionosphere model depends on what has the tilt angle to the ionosphere penetration point closest to 90 ° (eg, the user position is at the center of the ionosphere map). All up-to-date SBAS information feed-forwards are provided when requested and it requires additional ranging provided by the SBAS satellite in order for the client receiver to get DGPS and completeness This means that you may not need to track the SBAS satellite at all.

  There may be a need to adjust for any potential health or DGPS correction differences between systems. For example, the ionosphere model is more accurate in the United States when using WAAS SV. Another ionosphere model for the same PRN may be from eg EGNOS. With master DGPS correction, the US system (ie WAAS) would be preferred when the user location is closer.

  Although the present invention has been described in terms of presently preferred embodiments, it is understood that this disclosure should not be construed as limiting. Various changes and modifications will no doubt become apparent to those skilled in the art after reading the above disclosure. Accordingly, it is intended that the appended claims be construed to include all such changes and modifications as fall within the scope of the invention.

100-SBAS Configuration 101-104-Client 106-GPS Satellite 108-GLONASS Satellite 111,210-WAAS
112, 211-EGNOS
113,212-MSAS
114,213-GAGAN
115, 214-StarFire
116,215-OmniSTAR
121-126, 204-209-SBAS receiver 130,200-Internet server 132,224-PRN adjustment processor 134,226-satellite PRN database 202-Internet 220-SBAS accumulator 222-PRN processor 228-client request processor 230- present location

Claims (10)

In assisted satellite navigation systems with multiple SBAS reference receivers for strategic locations around the world that receive corresponding SBAS messages from at least WAAS, EGNOS, MSAS, and GAGAN SBAS systems,
A satellite navigation system support server that collects corresponding SBAS messages from the plurality of SBAS reference receivers and calculates satellite vehicle (SV) health, DGPS information, SBAS ephemeris and almanac, and PRN mask for different parts of the world; ,
A PRN adjustment process that adjusts specific PRN replicated between independent SBAS systems;
A PRN database for storing the SBAS messages collected from the plurality of SBAS reference receivers according to the PRN;
The satellite navigation system support server is configured to respond to a client request including an indication of a client location, and if the exact location is included in the server request, the satellite navigation system support server determines which specific It is calculated whether the SBAS system is observable from the requesting client, and in this case, the satellite navigation system support server restricts the response to related information for a more compact response message. Supporting satellite navigation system.   The satellite navigation system support server, along with DGPS correction values and health for any GPS, GLONASS, Galileo, and SBAS satellites based on data received from at least one SBAS observation reference point monitoring at least one SBAS system Responds to client requests and provides a global PRN mask referenced by the PRN used by the transmitting SBAS satellite so that the client uses these PRN masks prior to searching for any SBAS PRN And a reference table by longitude is provided to inform the client which SBAS PRNs are visible and healthy, so that the client can limit their search to visible SBAS satellites, 2. The assisted method of claim 1, wherein the client saves time to obtain a data message from an unhealthy SBAS satellite. Engineering satellite navigation system.   The satellite navigation system support server provides a superset of all SBAS ephemeris, so that any satellite can be used quickly for ranging at position fix, and long-term SBAS ephemeris Included to help clients use SBAS for longer ranging usefulness time if is too weak to get data but strong enough to identify code phase The support type satellite navigation system according to 1.   The satellite navigation system support server is configured to minimize the amount of SBAS and GNSS information sent when the client provides position and error estimates, and the longitude range is computed Appropriate SBAS and GNSS information is visible to each client, visible satellites within such longitude range, DGPS corrections and health of each satellite, ephemeris for healthy SBAS satellites, and visible in said longitude range The assisted satellite navigation system of claim 1, wherein the assisted satellite navigation system is sent to a superset of PRN masks for each SBAS or GNSS PRN.   The assisted satellite navigation system of claim 1, wherein the client can thereby save power consumed during the search and can reduce acquisition time by searching only the visible SBAS PRN.   When determining the DGPS correction value, the satellite navigation system support server selects an SBAS system having a better service area for a specific SV, and prioritizes the DGPS correction value based on the SBAS system. The assisted satellite navigation system according to claim 1 to be provided.   When the satellite navigation system support server determines which SBAS system to use for the ionosphere model, it supports the one with the inclination angle closest to the penetration point of the ionosphere of 90 °, and all the current SBAS information The assisted satellite navigation system of claim 1, wherein feed forward is provided upon request.   2. The support type satellite navigation system according to claim 1, wherein the satellite navigation system support server adjusts a difference between health and DGPS correction values detected between SBAS systems. A satellite navigation system support server configured to respond to a client request including an indication of a client location,
If the exact location is included in the server request, the satellite navigation system support server calculates which particular SBAS system is observable from the requesting client, and in this case, the satellite The navigation system support server is a satellite navigation system support server that limits the response to related information for a more compact response message. A satellite navigation system support server,
Internet presence with access to client satellite navigation system receivers,
Multiple SBAS reference receivers for strategic locations around the world, each adapted to receive and process SBAS broadcasts from one of independent WAAS, EGNOS, MSAS, and GAGAN SBAS systems And being configured,
An SBAS accumulator that collects corresponding SBAS messages from the plurality of SBAS reference receivers and calculates GNSS satellite vehicle (SV) health, DGPS information, SBAS ephemeris and almanac;
A PRN processor that identifies the SVs according to their assigned pseudo-random number (PRN) modulation codes and forwards the appropriate PRN masks for specific clients according to visible SBAS satellites from their respective locations around the world When,
A PRN database that stores information generated by the SBAS accumulator and the PRN processor according to the corresponding SV PRN;
To clients on the Internet who need at least general ideas about their current location and that they need appropriate GNSS information regarding SV health, DGPS information, SBAS ephemeris and almanac A client request processor that responds and provides an appropriate PRN mask from the PRN database;
The satellite navigation system support server is configured to respond to a client request including an indication of a client location, and if the exact location is included in the server request, the satellite navigation system support server determines which specific The satellite navigation system calculates whether the SBAS system is observable from the requesting client, and in this case, the satellite navigation system support server limits the response to related information for a more compact response message. Support server.

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