Method for Checking the Integrity of GNSS Correction Data Provided without Associated Integrity Information

Abstract

The disclosure relates to a method for checking the integrity of GNSS correction data, comprising at least the following steps: a) receiving GNSS correction data, which are provided without associated integrity information, b) receiving reference data which allow for a conclusion to be drawn in respect of the integrity of the GNSS correction data received in step a), and c) checking the integrity of the GNSS correction data received in step a) by means of the reference data received in step b).

Claims

1. A method for checking an integrity of first GNSS correction data, the method comprising: a) receiving the first GNSS correction data which are provided without associated integrity information; b) receiving reference data which allow for a conclusion to be drawn as to the integrity of the first GNSS correction data; and c) checking the integrity of the first GNSS correction data using the reference data.

2. The method as claimed in claim 1, wherein the first GNSS correction data are provided by a correction data provider which at least one of (i) does not carry out an integrity check and (ii) offers no integrity information for the first GNSS correction data.

3. The method as claimed in claim 1, wherein the reference data comprise orbit data.

4. The method as claimed in claim 1, wherein the reference data comprise second GNSS correction data, which are provided with associated integrity information.

5. The method as claimed in claim 1, wherein the reference data comprise second GNSS correction data which are provided by a correction data provider that differs from a correction data provider that provided the first GNSS correction data.

6. The method as claimed in claim 1, wherein the c) checking includes at least one of a comparison, a validation, and a merging of the first GNSS correction data with the reference data.

7. A method for providing integrity data for first GNSS correction data which are provided without associated integrity information, the method comprising: determining integrity data for the first GNSS correction data by a) receiving the first GNSS correction data, b) receiving reference data which allow for a conclusion to be drawn as to an integrity of the first GNSS correction data, and c) checking the integrity of the first GNSS correction data using the reference data; and providing the integrity data for the first GNSS correction data.

8. A method for providing first GNSS correction data to a GNSS receiver, the method comprising: at least one of checking an integrity of the first GNSS correction data and determining integrity data for the first GNSS correction data by a) receiving the first GNSS correction data which are provided without associated integrity information, b) receiving reference data which allow for a conclusion to be drawn as to the integrity of the first GNSS correction data, and c) checking the integrity of the first GNSS correction data using the reference data; and providing the first GNSS correction data to the GNSS receiver.

9. The method according to claim 1, wherein the method is carried out by a computer program.

10. The method according to claim 9, wherein the computer program is stored on a non-transitory machine-readable storage medium.

Description

[0029] The solution presented here as well as its technical background will be explained in more detail below on the basis of the figures. It should be noted that the invention is not intended to be limited by the exemplary embodiments. In particular, unless explicitly indicated otherwise, it is also possible to extract partial aspects of the facts explained in the figures and to combine them with other components and/or information from other figures and/or the present description. In the drawings, schematically in each case:

[0030] FIG. 1 shows an example graphic illustration of the provision of GNSS correction data according to the prior art,

[0031] FIG. 2 shows a flowchart of the method presented here for checking the integrity of GNSS correction data,

[0032] FIG. 3 shows an exemplary graphic illustration of the method presented here for providing GNSS correction data to a GNSS receiver, and

[0033] FIG. 4 shows an exemplary flow diagram of the method presented here for providing GNSS correction data to a GNSS receiver.

[0034] FIG. 1 shows a schematic graphic illustration of the provision of GNSS correction data 1 according to the prior art. Three GNSS satellites of different constellations 7 are shown, a correction data provider 4 receiving the signals of the GNSS satellite 7 that receives the signals at a known geodetic position, and a mobile GNSS receiver 6 that also receives the signals of the GNSS satellite 7. The correction data provider 4 determines GNSS correction data 1 from the received signals, for example by comparing it with the known geodetic position.

[0035] In addition, this correction data provider 4 determines, for example, the integrity information associated with the GNSS correction data 1 provided by it and generates integrity data 5 from this information. The correction data provider 4 provides the GNSS correction data 1 in combination with the associated integrity data 5 to the GNSS receiver 6. This means that the GNSS receiver 6, which can be, for example, a GNSS receiver 6 of a vehicle that is driven at least partially autonomously, can detect from the integrity data 5 whether the GNSS correction data 1 provided meet a specific safety level (here an ASIL requirement, for example). If this is the case, the GNSS receiver 6 can correct the received GNSS signals with the GNSS correction data 1 and thus (reliably) improve its self-localization. In principle, the ASIL requirement can also be met if, for example, the integrity information is not available. If the integrity information is not available for checking, the data are usually classified as unverified and can therefore be deemed to be unsafe. The ASIL classification describes in particular a known design with, for example, different redundancies and checking modules that have been developed in accordance with corresponding process requirements.

[0036] FIG. 2 schematically shows a flowchart of the method presented here for checking the integrity of GNSS correction data 1. The steps a), b) and c) shown with blocks 110, 120 and 130 can be executed at least once in the sequence. In addition, at least the steps a) and b) can also be carried out at least partially in parallel or simultaneously. In block 110, according to step a), GNSS correction data 1 are received, which are provided without corresponding integrity information. In block 120, in accordance with step b) reference data 2 are received, which allow a conclusion to be drawn as to the integrity of the GNSS correction data 1 received in step a). In block 130, in accordance with step c) the integrity of the GNSS correction data received in step a) is checked with the reference data 2 received in step b).

[0037] FIG. 3 shows a schematic of an exemplary graphic illustration of the method presented here for providing GNSS correction data 1 to a (mobile) GNSS receiver 6. A method for integrity checking described here is performed. In this context, integrity data 5 are also provided to the GNSS receiver 6. The integrity data 5 are provided for the GNSS correction data 1, which are provided (by the providing correction data provider 3) without associated integrity information. A method described here for integrity checking is carried out to determine the integrity data 5. In this regard, reference is made to the explanations given for FIG. 2.

[0038] In FIG. 3 the GNSS correction data 1 received in step a) are provided by a correction data provider 3 which does not carry out an integrity check and/or offers no (associated) integrity information for the GNSS correction data 1. These GNSS correction data 1 are also provided (without integrity information or directly) to a GNSS receiver 6. This GNSS receiver 6 is also provided with (and independently of or in parallel) the integrity data 5 for the GNSS correction data 1 that are determined in accordance with the integrity checking method described here. This allows the GNSS receiver 6 to check whether the GNSS correction data 1 meet a certain (specified) safety level or not.

[0039] The reference data 2 received in step b) here comprise, for example, GNSS correction data that are provided by a correction data provider 4 which differs from the correction data provider 3 that provides the GNSS correction data 1 received in step a). Furthermore, as an example, the reference data 2 received in step b) here comprise GNSS correction data which are provided with associated integrity information.

[0040] Alternatively or in addition, the received reference data 2 may be GNSS correction data that are provided without any associated integrity information but by a correction data provider 4 which is different from the correction data provider 3 which provides the GNSS correction data 1 received in step a). Furthermore, the reference data 2 received in step b) may additionally or alternatively comprise orbit data, satellite clock data, regional and/or global corrections for ionosphere and/or troposphere.

[0041] For example, the checking in step c) comprises comparing and/or merging the GNSS correction data 1 received in step a) with the reference data 2 received in step b). A more detailed example of this is described below in conjunction with FIG. 4.

[0042] FIG. 4 shows a schematic of an exemplary flowchart of the method presented here for providing GNSS correction data 1 to a GNSS receiver 6. The data provided by various correction data providers 3, 4 are subjected to an input check 10 with regard to value range, completeness, and/or topicality. Various auxiliary data 8, 9 can also be taken into account. The auxiliary data can be, for example, orbit data of the IGS (International GNSS Service) and/or the CODE (Center of Orbit Determination Europe). But the use of global tropospheric models (e.g. UNB3 from the University of New Brunswick) and/or global ionosphere models (such as Ionosphere Maps) are also conceivable for plausibility checking. This is followed by a time synchronization 11 of the data. The data are checked for plausibility and/or normalized as part of a normalization and/or plausibility check 12 with regard to the data features (example: relative correction parameters are converted to absolute correction parameters using the broadcast ephemeris values).

[0043] According to the specified parameters, the correction data and any auxiliary data (from the normalization and/or plausibility check 12) are compared with each other in a comparison 13. The comparison result is re-used as part of a selection 4. Individual data elements, data attributes or complete data streams are discarded or forwarded based on the comparison results from the comparison 13. In the last (assembly) step 15, selected correction and auxiliary data from the selection 14 are assembled in a new correction data stream. The correction data stream contains the GNSS correction data 1 and the integrity data 5 for these correction data 1.

[0044] In particular, the methods presented here allow the advantage that GNSS correction data provided without corresponding integrity information can also be used in connection with at least partially autonomous driving, which usually places high demands on the integrity of the data used.