WO2010049088A1

WO2010049088A1 - Guidance system, and method for identifying an at least local disruption in a satellite-aided positioning system comprising a guidance system

Info

Publication number: WO2010049088A1
Application number: PCT/EP2009/007556
Authority: WO
Inventors: Thomas Feuerle; Peter Hecker
Original assignee: Technische Universität Braunschweig Carolo-Wilhelmina
Priority date: 2008-10-28
Filing date: 2009-10-22
Publication date: 2010-05-06
Also published as: DE102008053508A1

Abstract

A guidance system (1) is described that comprises a plurality of regionally distributed navigational guidance stations (2) which are interlinked to form a navigational guidance unit (4a, 4b, 4c) and have satellite-aided locating receivers (8) for receiving time signals in order to synchronize time by means of the time signals. The guidance system (1) further comprises at least one satellite-aided guidance device that uses location receivers (8), and at least one monitoring unit for monitoring the local availability of a satellite-aided locating function. The guidance system (1) is designed to identify an at least local disruption in the satellite-aided locating system by combining and correlating signals from the regionally distributed locating receivers (8) of the navigational guidance stations (2), said signals being generated during the locating process.

Description

Guidance system and method for detecting an at least local disturbance of a satellite-based positioning system with a guidance system

The invention relates to a control system with a plurality of distributed regionally distributed and networked to a navigation unit Leitstationen, the satellite-based position locating receiver for receiving time signals for time synchronization by means of the time signals, with at least one satellites position location receiver using the guide and at least one monitoring unit for monitoring the local availability satellite-based position location.

The invention further relates to a method for detecting an at least local disturbance of a satellite-based positioning system with such a guidance system.

For example, to guide vehicles, in particular aircraft knowledge of the exact position of the vehicle is required. This can be detected quickly, easily and inexpensively, for example with the aid of satellite-based position location receiver. In this case, the transit times of a plurality of time signals receivable by the position location receiver are received and evaluated by positioning satellites. Such global navigation satellite systems (GNSS) are, for example, the US Global Positioning Systems GPS, the Russian system GLONASS, the future European system Galileo including the supporting Space Based Augmentation Systems (SBAS), such as the European system EGNOS (European Geostationary Navigaiton Overlay Signal), the US Wide Area Augmentation System (WAAS) or the Multi-Transport Satellite Based Augmentation System (MSAS) and the GBAS GB (in the United States as well) referred to as FAA Local Area Augmentation System LAAS). In safety-critical, high-precision positioning applications, such as B. based on landings of aircraft Satellite based positioning is to ensure that the position information obtained from the satellite positioning is correct.

One problem with satellite-based position determination is, on the one hand, localized disturbances, for example due to shadowing, and, on the other, more extensive disturbances, in particular due to atmospheric influences. Many causes of satellite positioning systems may include satellite clock errors, satellite orbit orbiting, satellites orbiting, receiver noise, multipath reception, and ionosphere and troposphere refractions. Ionospheric perturbations occur primarily in the vicinity of the magnetic poles or magnetic erosion of the earth. The intensity of ionospheric disturbances depends on solar activities. Also, with increased solar activity significantly larger areas of the earth's surface are affected by corresponding ionospheric disturbances.

A. Komjathy, L. Sparks, AJ Mannucci, A. Coster: The Ionsheric Impact of the Octo- ber 2003 Storm Event on Wide Area Augmentation System, in GPS Solution (2005) 41 50 describe an investigation of the iono- ion-induced ionic activity. spherical interference on satellite navigation systems. While errors of less than 0.8 meters are observed in periods of low ion activity, the error in days of solar storms is less than 10 meters.

K. Van Dyke, J. Parmet, C. Dufresne, A. Hansen, R. CoIe, J. Campbell, J. She, Y. Bian, R. Loh: GNSS Real Time Performance Monitoring and CNS / ATM Implementation in: Position , Location and Navigation Symposium, 2006, IEEE / ION, April 25-27, 2006, pages 1137-1144 describes a performance monitoring system for satellite-based global navigation systems GNSS built in Brazil. Spatially distributed, local monitoring stations are located and interconnected to continuously monitor GNSS signals and monitor the performance of the GNSS system in real time. From this, however, the local availability of a satellite positioning system can not be determined. T. Walter, S-Pullen, J. Rife, J. Seo and P. Enge: The Advantages of Local Monitoring and VHF Data Broadcast for SBAS, European Navigation Conference GNSS 2005, June 2005, Munich describes a local surveillance system in which a local GPS receiver Corrections of a Space Based Augmentation System SBAS checks and sends local health parameters in GBAS (Ground Based Augmentation System) format. This should improve the availability of SBAS approaches.

Proceeding from this, it is an object of the present invention to provide an improved guidance system with a plurality of regionally distributed and networked to a navigation control unit navigation control stations, with the local disturbances of a satellite-based Positionor- can be recognized system in a simple and inexpensive way.

The object is achieved with the control system of the type mentioned by the fact that the control system for detecting an at least local disturbance of the satellite-based position location system by merging and correlation of occurring in the position location signals of the regionally distributed satellite positioning receiver of the Navigationsleitstationen is set up. It is proposed to use the satellite-supported position location receivers which are present in any case in the navigation control stations for receiving time signals for time synchronization not only for time synchronization, but also for detecting at least local interference of the satellite-supported position location system. The position locating receivers which are present anyway in the navigation control station are thus additionally used for fault detection, without the need for further hardware expenditure. The additional functionality can be implemented in a simple manner, for example by additional software.

An advantage of the position location receiver of the modified navigation control station is that the navigation control station is usually already closely available. For air traffic control, for example, ADS-B stations are distributed over land to receive transponder signals from aircraft. A uniform time base is provided by the GPS time obtained with GP S receivers, which includes a Timestamp for the data packets containing transponder information supplies.

Signals of the regionally distributed satellite-supported position-location receivers of the navigation control stations which are collected during position location are brought together and correlated with one another in order to obtain statements about the local availability of the satellite-supported position location system.

The control system can be set up, for example, to detect an at least local disturbance as a function of filter-extracted runtime disturbances of the signals sent by satellites to position locating receivers. Such filtering is deterministic and thus provides a predictable result. By filtering maturities used for determining the position, for example, short-term changes can be registered. Jumps in the recorded transit times indicate disturbances. Such jumps can be detected by time derivations of the propagation time information, whereby disturbances can be detected on the basis of the temporary changes of the time-derived runtime signal.

The navigation control stations preferably contain transponder signal receivers for receiving navigation signals from vehicles, for example, such as aircraft, and are set up for the time synchronization of the navigation signals by means of the time signals and for the transmission of the time-synchronized navigation signals in the control system. The transponder signal receivers are further used according to the teachings of the present invention to obtain from the runtime signals information about the local quality and availability of the satellite positioning system. The control system can furthermore be set up to detect an at least local disturbance as a function of Doppler effects occurring in the navigation control stations during position determination with the regionally distributed satellite-based position location receivers. In this way, errors generated by moving objects and reflections can be detected, which limit the local availability of the satellite-based position location system. It is furthermore advantageous to determine the local availability of the satellite-supported position location system on the basis of a comparison of the availability of position location receivers to adjacent navigation control stations. With a limited availability of at least two position locating receivers of a group of adjacent satellite-based position locating receivers, then a local disturbance of the satellite-supported position locating system is concluded. In this test, the availability of a group of adjacent satellite-based position locator receivers is determined and compared.

The object is further achieved by the method for detecting an at least local disturbance of a satellite-based position locating system with such a control system by merging and filtering of locating located in position signals regionally distributed satellite position locating receiver of Navigationsleitstationen and transmitting a detected at least local disturbance of the satellite-based position location system to one of the navigational control stations forming a navigation control unit independent guidance devices.

Advantageous embodiments are described in the subclaims.

The invention will be explained in more detail with reference to an embodiment with the accompanying drawings. Show it:

Figure 1 - block diagram of a control system with a plurality of regionally distributed and to a navigation control unit networked navigation control station;

Figure 2 - sketch of a Navigationsleitstation with satellite-based

Position locator for time synchronization and detection of an at least local fault. FIG. 1 shows a block diagram of a control system 1 which has a multiplicity of navigation control stations 2 arranged regionally. The navigation control stations are, for example, ADS-B stations of an air traffic control system. The ADS-B stations have transponder signal receivers for receiving aircraft navigation signals and satellite position locating receivers, such as GP S receivers, which are used exclusively to receive time signals for time synchronization of the received transponder signals by means of the time signals received via the satellite-based position location system.

The navigation control stations 2 are connected to each other via an associated central 3a, 3b, 3c to a Navigationsleiteinheiten 4a, 4b, 4c.

The navigation control units 4a, 4c are associated, for example, with an airport A or an airport B. The central units a, b, x, 3a, 3b, 3c may optionally be connected to further local cells 5a, 5b. In the navigation control stations 2, satellite position-based position location signals are received and combined and correlated with one another in order to detect at least local interference of the satellite-supported position location system. For this purpose, for example, runtime signals of the adjacent navigational control stations 2 can be compared with one another and deviations can be used to detect runtime disturbances and local disturbances of the satellite-supported position locating system. The use of the ADS-B stations 2 for the purpose of detecting local controls of the satellite-based position location system also has the advantage that the density distribution of the ADS-B stations near the airport is higher and the location of the GPS antennas is as far as possible free of multiple lanes. The receivers contained in the Navigationsleitstationen 2 also provide other signals, such as Doppler frequency, quantification factors, etc., which can be evaluated to detect local disturbances of the satellite-based position location system. Temporary multipath propagation disturbances and receiver-specific problems can be eliminated from the correlation of the position location signals, in particular the transit times, by suitable filter algorithms in central computer units. By combining and correlating the signals obtained during position location, in particular the transit times, of the regionally distributed satellite-based position location receivers of the navigation control stations, local atmospheric disturbances can be detected and visualized, for example. It is thus possible to detect the direction and strength of any ionospheric disturbances and to identify possible timing errors.

The use of the networked navigational control stations 2 for detecting at least local control of the satellite-supported position location system has the advantage that the existing hardware can be used and the density of regionally distributed navigation control stations 2 is relatively high, especially in air traffic control systems.

The guidance system 1 can similarly be constructed for other traffic systems, such as trains, road traffic, etc., and the traffic system can be used for this purpose.

FIG. 2 shows a sketch of a navigation control station 2 with a transponder signal receiver 6, which is provided for receiving transponder signals T, which are transmitted for the purpose of identifying aircraft 7. To provide these transponder signals T with a time stamp, the transponder signal receiver 6 has a position location receiver 8, which has so far been submitted only for receiving time information from satellites 9.

The position location receiver 8 is now further used to evaluate position sorting signals, such as, in particular, runtime signals in order to detect local disturbances of the satellite-supported location system. However, as a single device, the position locator 8 is incapable of detecting any critical disturbances, such as disturbances resulting from increased electron activity in the ionosphere. In combination with the navigation control units 2, however, it is possible by means of a selection of suitable filter algorithms to detect and eliminate local false alarms, so that only actual faults which are further taken into account by the user are considered several navigation control units 2 were confirmed simultaneously. The navigation control units 2 require only relatively simple position location receivers 8, which themselves do not have to be equipped to detect disturbances, for example in the ionosphere. The combination and correlation of the position location resulting signals, in particular run times, the plurality of regionally distributed satellite position locating receivers 8 makes it possible to detect local disturbances and thereby eliminate local, to a position locating receiver 8 related problems by comparing the signals of adjacent Navigationsleitstationen 2.

By using the existing ADS-B stations 2 including the connected GPS receivers to monitor the GPS constellations of the current performance of the GPS system, it is possible to predict the impact of detected ionospheric disturbances. For this purpose, a network of existing GPS-Ll receivers within an ATM network is used. The essential parameters of a satellite navigation system can also be monitored within an air traffic management ATM (Air Traffic Management ATM) or an air traffic control (Air Traffic Control ATC) data network and it is a statement about the integrity of a position received by ADS-B due to the determined current performance of a satellite navigation system is possible.

The control system 1 thus creates the prerequisite for the use of satellite-based position location in the traffic control, without additional infrastructure is required.

Claims

claims

1. control system (1) with a plurality of regionally distributed and to a navigation control unit (4a, 4b, 4c) networked navigation substations

(2) having satellite-based position locating receivers (8) for receiving time signals for time synchronization by the time signals, with at least one satellite positioning position receiver (8) using the guide and at least one monitoring unit for monitoring the local availability of satellite-based position location, characterized in that the control system (1) for detecting at least local disturbance of the satellite-based position locating system by merging and correlating occurring in the position location signals of the regionally distributed satellite position locating receiver (8) of the navigational control stations (2) is set up.

2. Control system (1) according to claim 1, characterized in that the control system for detecting an at least local disturbance in response to extracted by filtering runtime noise of the satellites for position location receivers (8) emitted signals is set up.

3. Control system (1) according to claim 2, characterized in that the control system (1) is arranged for the time derivative of the propagation time information and detection of disturbances on the basis of temporary changes in the time-derived time-of-flight signal.

4. control system (1) according to any one of the preceding claims, characterized in that the Navigationsleitstationen (2) Transpondersignal- receiver (6) for receiving navigation signals from vehicles and for time synchronization of the navigation signals by means of the time signals and

Transmission of time-synchronized navigation signals is set up in the control system.

5. Control system (1) according to one of the preceding claims, characterized in that the control system (1) for detecting an at least local disturbance as a function of when determining the position with the regionally distributed arranged satellite positioning position receivers

Navigationsleitstationen (2) occurring Doppler effects is set up.

6. Control system (1) according to one of the preceding claims, characterized by comparing the availability of a group of adjacent satellite-based position locating receiver (8) of Navigationsleitstationen (2) and detecting a local disturbance of the satellite-based position location system with a limited availability of at least two position locating receivers (8).

7. Control system (1) according to one of the preceding claims, characterized in that the control system is provided for controlling the air traffic and that Navigationsleitstationen (2) are ADS-B stations.

8. A method for detecting an at least local disturbance of a satellite-based position location system with a control system (1) according to one of the preceding claims, characterized by merging and filtering obtained in the position location signals regionally distributed satellite position locating receiver (8) of Navigationsleitstationen (2) and transmitting a detected at least local interference of the satellite-based position location system with one of the ones

Navigation control unit (4a, 4b, 4c) forming navigation control stations (2) independent guidance devices.

9. The method according to claim 7, characterized by detecting an at least local disturbance depending on extracted by filtering

Runtime disturbances of the signals emitted by satellites (9) to position location receivers (8).

10. The method according to claim 8, characterized by temporal derivation of the propagation time information and detection of interference based on temporary changes in the time-derived runtime signal.

11. The method according to any one of claims 8 to 10, characterized by detecting an at least local disturbance as a function of in determining the position with the regionally distributed arranged satellite positioning detectors (8) of the Navigationsleitstations (2) occurring Doppler effects.

12. The method according to any one of claims 8 to 11, characterized by comparing the availability of a group of adjacent satellite-based position locating receiver (8) of Navigationsleitstationen (2) and detecting a local disturbance of the satellite-based position locating system with a limited availability of at least two position locating receivers (8).

13. The method according to any one of claims 8 to 12, characterized by controlling the air traffic by means of the guide (2), in particular for satellite-based approach control of aircraft (7), wherein the Navigationsleitstationen (2) are ADS-B stations.