阅读说明：本技术 一种vrs格网点零信任检核系统及方法 (VRS grid point zero trust checking system and method ) 是由 王孝青 武军郦 陈明 张鹏 张庆兰 于 2021-08-13 设计创作，主要内容包括：本发明涉及一种VRS格网点零信任检核系统及方法,接收CORS计算系统生成的VRS格网点数据；对VRS格网点数据进行解码,拦截非法消息；检测解码后的VRS格网点数据剔除无法提供CORS服务的数据；剔除VRS格网点的观测数据与虚拟坐标的几何模型一致性不满足要求的数据；将VRS格网点数据编码后推送给对应的定位终端。本发明实现了对VRS数据的安全、快速校核,提高了数据的安全性和可靠性；剔除了精度误差不满足要求的卫星数据,保证数据精度和可靠性。本发明的粗差检核,快速有效,避免了大量占用计算资源。(The invention relates to a VRS grid point zero trust checking system and a method thereof, which receives VRS grid point data generated by a CORS computing system; decoding VRS grid data and intercepting illegal messages; detecting the decoded VRS grid data and eliminating data which can not provide CORS service; eliminating data which are not satisfied with the requirement on the consistency of the observation data of the VRS grid points and the geometric model of the virtual coordinate; and encoding the VRS grid point data and then pushing the encoded VRS grid point data to the corresponding positioning terminal. The invention realizes the safe and rapid checking of the VRS data and improves the safety and reliability of the data; satellite data with accuracy errors not meeting requirements are eliminated, and data accuracy and reliability are guaranteed. The gross error checking of the invention is quick and effective, and avoids occupying a large amount of computing resources.)

1. A VRS grid point zero trust checking system is characterized by comprising a receiving module, a decoding module, a minimum service standard detection module, a gross error detection module and an output module;

the receiving module receives VRS grid point data generated by the CORS computing system;

the decoding module decodes the VRS grid point data, intercepts illegal messages and transmits the illegal messages to the minimum service standard detection module;

the minimum service standard detection module detects whether the decoded VRS grid point data comprises minimum data required by CORS service, if yes, the minimum service standard detection module transmits the minimum data to the gross error detection module, and if not, the minimum service standard detection module discards the decoded VRS grid point data;

the gross error detection module judges whether the consistency of the observation data of the VRS grid points and the geometric model of the virtual coordinates meets the requirement, if so, the observation data of the VRS grid points and the geometric model of the virtual coordinates are transmitted to the output module, otherwise, the observation data of the VRS grid points and the geometric model of the virtual coordinates are discarded;

and the output module is used for coding the VRS grid point data transmitted by the gross error detection module and then pushing the coded VRS grid point data to a corresponding positioning terminal.

2. The VRS mesh point zero trust checking system of claim 1, wherein the decoding module culls VRS mesh point data that does not conform to the format specification and is not defined in a security dictionary based on the security dictionary of the RTCM data.

3. The VRS mesh point zero trust check system of claim 1 or 2, wherein the minimum data required to provide the CORS service comprises: satellite ephemeris, satellite observations, and VRS station coordinates.

4. The VRS mesh point zero-trust check system of claim 1 or 2, wherein determining whether the observed data of the VRS mesh point is consistent with the geometric model of the virtual coordinates comprises: calculating a first distance from each satellite to a VRS grid point according to the satellite ephemeris and the coordinates of the VRS grid point, obtaining a second distance from each satellite to a survey station based on observation data according to the satellite observation value of the VRS grid point, calculating an error between the first distance and the second distance for each satellite, and if the consistency of the errors meets requirements, the data of the satellite meets the consistency requirements and the data of the satellite which does not meet the consistency requirements are removed.

5. The VRS mesh point zero-trust verification system of claim 4,

the calculation of the first distance Pi from the ith satellite to the survey station based on the virtual coordinates comprises:

wherein X_s，Y_s，Z_sIs the satellite coordinates obtained from the satellite ephemeris in the VRS grid data, X, Y, Z are the previously known VRS station coordinates, dt_RIs the clock difference, dt, of the station-finding receiver_SIs the satellite's clock error obtained from the satellite ephemeris in the VRS grid data, and c is the speed of light.

Further, the clock difference calculation of the station survey receiver comprises: when the first distance is calculated, the clock error of the station measuring receiver is set to be 0, and the first distances of all satellites have a reference deviation; calculating the differences di between the first distances and the second distances of all the satellites, then calculating the average value of di as a reference deviation criterion value, calculating the deviation of each satellite reference deviation and the reference deviation criterion value, and if the deviation is within a set range, the satellite data meets the consistency requirement.

6. A VRS grid point zero trust checking method is characterized by comprising the following steps:

(1) receiving VRS grid point data generated by a CORS computing system;

(2) decoding VRS grid data and intercepting illegal messages;

(3) detecting whether the decoded VRS grid data comprises minimum data required by CORS service, if yes, entering the step (4), and if not, discarding;

(4) judging whether the consistency of the observation data of the VRS grid points and the geometric model of the virtual coordinates meets the requirement, if so, entering the step (5), otherwise, abandoning;

(5) and encoding the VRS grid point data and then pushing the encoded VRS grid point data to the corresponding positioning terminal.

7. The VRS grid point zero trust check system of claim 6, wherein the decoding in step (2) comprises: and according to the security dictionary of the RTCM data, eliminating the VRS grid point data which does not conform to the format specification and is not defined in the security dictionary.

8. The VRS mesh point zero trust check method of claim 6 or 7, wherein the minimal data required to provide CORS services comprises: satellite ephemeris, satellite observations, and coordinates of VRS grid points.

9. The VRS mesh point zero-trust checking method of claim 6 or 7, wherein the determining whether the observed data of the VRS mesh point is consistent with the geometric model of the virtual coordinates comprises: calculating a first distance from each satellite to a VRS grid point according to the satellite ephemeris and the coordinates of the VRS grid point, obtaining a second distance from each satellite to a survey station based on observation data according to the satellite observation value of the VRS grid point, calculating an error between the first distance and the second distance for each satellite, and if the consistency of the errors meets requirements, the data of the satellite meets the consistency requirements and the data of the satellite which does not meet the consistency requirements are removed.

10. The VRS grid point zero trust check method of claim 9,

the calculation of the first distance Pi from the ith satellite to the survey station based on the virtual coordinates comprises:

wherein X_s，Y_s，Z_sIs the satellite coordinates obtained from the satellite ephemeris in the VRS grid data, X, Y, Z are the previously known VRS station coordinates, dt_RIs the clock difference, dt, of the station-finding receiver_SIs the satellite's clock bias obtained from the satellite ephemeris in the VRS grid data,and c is the speed of light.

Further, the clock difference calculation of the station survey receiver comprises: when the first distance is calculated, the clock error of the station measuring receiver is set to be 0, and the first distances of all satellites have a reference deviation; calculating the differences di between the first distances and the second distances of all the satellites, then calculating the average value of di as a reference deviation criterion value, calculating the deviation of each satellite reference deviation and the reference deviation criterion value, and if the deviation is within a set range, the satellite data meets the consistency requirement.

Technical Field

The invention relates to the technical field of satellite navigation, in particular to a VRS grid point zero trust checking system and a VRS grid point zero trust checking method.

Background

With the development of technologies such as the internet of things and unmanned driving, the number of terminals for real-time positioning is increasing, and the CORS service is more and more demanded as one of the technologies with the highest maturity and precision in the aspect of satellite navigation. At present, each province in China provides CORS service based on VRS technology, namely, a nearby virtual reference station is provided for an accessed positioning terminal for differential positioning.

In order to meet the requirements of a large number of users, the CORS service in part of regions generates grid VRS data in advance, stores the grid VRS data in the system, and updates the grid VRS data in real time at a second level. When processing these data, a zero trust check is required to enforce the security audit. The zero trust check is not only based on security considerations, but also guarantees on data reliability.

However, an effective zero trust check for the CORS service has not been implemented, which leads to security concerns for VRS data.

Disclosure of Invention

Aiming at the problems in the prior art, the invention provides a VRS grid point zero trust checking system and a VRS grid point zero trust checking method, which meet the requirements of high-precision quick positioning and real-time service of users, strengthen safe quick checking, realize zero trust checking and ensure the safety and reliability of VRS real-time grid service data.

In order to achieve the above object, the present invention provides a VRS grid point zero trust checking system, which comprises a receiving module, a decoding module, a minimum service standard detecting module, a gross error detecting module and an output module;

the receiving module receives VRS grid point data generated by the CORS computing system;

the decoding module decodes the VRS grid point data, intercepts illegal messages and transmits the illegal messages to the minimum service standard detection module;

the minimum service standard detection module detects whether the decoded VRS grid point data comprises minimum data required by CORS service, if yes, the minimum service standard detection module transmits the minimum data to the gross error detection module, and if not, the minimum service standard detection module discards the decoded VRS grid point data;

the gross error detection module judges whether the consistency of the observation data of the VRS grid points and the geometric model of the virtual coordinates meets the requirement, if so, the observation data of the VRS grid points and the geometric model of the virtual coordinates are transmitted to the output module, otherwise, the observation data of the VRS grid points and the geometric model of the virtual coordinates are discarded;

and the output module is used for coding the VRS grid point data transmitted by the gross error detection module and then pushing the coded VRS grid point data to a corresponding positioning terminal.

Furthermore, the decoding module eliminates VRS grid point data which does not conform to the format specification and is not defined in the security dictionary according to the security dictionary of the RTCM data.

Further, the minimum data required to provide the CORS service includes: satellite ephemeris, satellite observations, and VRS station coordinates.

Further, judging whether the observation data of the VRS grid points are consistent with the geometric model of the virtual coordinates or not comprises the following steps: calculating a first distance from each satellite to a VRS grid point according to the satellite ephemeris and the coordinates of the VRS grid point, obtaining a second distance from each satellite to a survey station based on observation data according to the satellite observation value of the VRS grid point, calculating an error between the first distance and the second distance for each satellite, and if the consistency of the errors meets requirements, the data of the satellite meets the consistency requirements and the data of the satellite which does not meet the consistency requirements are removed.

Further, the first distance P from the ith satellite to the survey station based on the virtual coordinates_iThe calculation comprises the following steps:

wherein X_s,Y_s,Z_sIs the satellite coordinates obtained from the satellite ephemeris in the VRS grid data, X, Y, Z are the previously known VRS station coordinates, dt_RIs the clock difference, dt, of the station-finding receiver_SIs the satellite's clock error obtained from the satellite ephemeris in the VRS grid data, and c is the speed of light.

Further, the clock difference calculation of the station survey receiver comprises: when the first distance is calculated, the clock error of the station measuring receiver is set to be 0, and the first distances of all satellites have a reference deviation; calculating the differences di between the first distances and the second distances of all the satellites, then calculating the average value of di as a reference deviation criterion value, calculating the deviation of each satellite reference deviation and the reference deviation criterion value, and if the deviation is within a set range, the satellite data meets the consistency requirement.

In another aspect, a VRS mesh point zero trust checking method is provided, including:

(1) receiving VRS grid point data generated by a CORS computing system;

(2) decoding VRS grid data and intercepting illegal messages;

(3) detecting whether the decoded VRS grid data comprises minimum data required by CORS service, if yes, entering the step (4), and if not, discarding;

(4) judging whether the consistency of the observation data of the VRS grid points and the geometric model of the virtual coordinates meets the requirement, if so, entering the step (5), otherwise, abandoning;

(5) and encoding the VRS grid point data and then pushing the encoded VRS grid point data to the corresponding positioning terminal.

Further, the decoding in step (2) includes: and according to the security dictionary of the RTCM data, eliminating the VRS grid point data which does not conform to the format specification and is not defined in the security dictionary.

Further, the minimum data required to provide the CORS service includes: satellite ephemeris, satellite observations, and coordinates of VRS grid points.

Further, judging whether the observation data of the VRS grid points are consistent with the geometric model of the virtual coordinates or not comprises the following steps: calculating a first distance from each satellite to a VRS grid point according to the satellite ephemeris and the coordinates of the VRS grid point, obtaining a second distance from each satellite to a survey station based on observation data according to the satellite observation value of the VRS grid point, calculating an error between the first distance and the second distance for each satellite, and if the consistency of the errors meets requirements, the data of the satellite meets the consistency requirements and the data of the satellite which does not meet the consistency requirements are removed.

Further, the calculating of the first distance Pi from the ith satellite to the survey station based on the virtual coordinates comprises:

wherein X_s,Y_s,Z_sIs the satellite coordinates obtained from the satellite ephemeris in the VRS grid data, X, Y, Z are the previously known VRS station coordinates, dt_RIs the clock difference, dt, of the station-finding receiver_SIs the satellite's clock error obtained from the satellite ephemeris in the VRS grid data, and c is the speed of light.

Further, the clock difference calculation of the station survey receiver comprises: when the first distance is calculated, the clock error of the station measuring receiver is set to be 0, and the first distances of all satellites have a reference deviation; calculating the differences di between the first distances and the second distances of all the satellites, then calculating the average value of di as a reference deviation criterion value, calculating the deviation of each satellite reference deviation and the reference deviation criterion value, and if the deviation is within a set range, the satellite data meets the consistency requirement.

The technical scheme of the invention has the following beneficial technical effects:

(1) the invention realizes the safe and fast check of the VRS data and improves the safety and the reliability of the data. And sensitive data leakage is avoided through layer-by-layer checking. The geometric characteristics of the data representation are fully utilized, and illegal data leakage can be effectively prevented.

(2) The invention eliminates satellite data with accuracy error not meeting the requirement, and ensures data accuracy and reliability.

(3) The gross error checking of the invention is quick and effective, and avoids occupying a large amount of computing resources. The coarse error checking scheme of the invention avoids least square in the conventional method, avoids matrix operation and improves checking efficiency.

(4) The invention ensures the validity of VRS data and the stability of CORS service, and by utilizing the checking mechanism of the invention, the validity evaluation of CORS service can be carried out, and an early warning mechanism is added, so that the stability of CORS service is improved even if the problem is fed back.

Drawings

FIG. 1 is a schematic diagram of a VRS grid point zero trust checking system;

FIG. 2 is a schematic diagram of the operation of a VRS grid point zero trust checking system;

FIG. 3 is a flow chart of zero trust checking for VRS mesh points;

FIG. 4 is a diagram of security dictionary auditing based on RTCM data.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention will be described in further detail with reference to the accompanying drawings in conjunction with the following detailed description. It should be understood that the description is intended to be exemplary only, and is not intended to limit the scope of the present invention. Moreover, in the following description, descriptions of well-known structures and techniques are omitted so as to not unnecessarily obscure the concepts of the present invention.

The invention provides a VRS grid point zero trust checking system, which is combined with a figure 1 and comprises a receiving module, a decoding module, a minimum service standard detection module, a gross error detection module and an output module;

and the receiving module receives the VRS grid point data generated by the CORS computing system.

With reference to fig. 2, after the cor computing system generates the VRS grid points, the VRS grid points are transmitted to the zero trust checking system, received by the receiving module, subjected to a series of processing to ensure the security and reliability of data, and then transmitted out of the system to the service access center.

And the decoding module decodes the VRS grid point data, intercepts illegal messages and transmits the illegal messages to the minimum service standard detection module.

Referring to fig. 4, a security dictionary of the RTCM data is added with a customized partial message ID based on a message ID defined in the RTCM standard. The security dictionary is controlled by an administrator. And decoding the VRS grid point data, allowing only the messages in the security dictionary to pass through and intercepting illegal messages. Decoding according to the standard, and intercepting if the decoding is out of the standard. The RTCM belongs to international standards, has a specific format specification defined by an official party, and carries out one-to-one check according to the format specification during checking.

And the minimum service standard detection module detects whether the decoded VRS grid point data comprises minimum data required by CORS service, if so, the data is transmitted to the gross error detection module, and if not, the data is discarded.

The RTCM defines the minimum message standard for the CORS VRS service, which must be included in the real-time service, otherwise there is no service capability. For example, a minimal CORS service contains at least the following messages: satellite ephemeris, satellite observations, VRS station coordinates. And checking the grid data according to the minimum service standard, and discarding the data if the grid data does not have service capability.

And the gross error detection module judges whether the consistency of the observation data of the VRS grid points and the geometric model of the virtual coordinates meets the requirement, if so, the observation data of the VRS grid points and the geometric model of the virtual coordinates are transmitted to the output module, and if not, the observation data of the VRS grid points and the geometric model of the virtual coordinates are discarded.

The gross error detection module judges whether the VRS grid point data detection observation data is consistent with the geometric model of the virtual coordinate or not, and comprises the following steps: and calculating to obtain a first distance from each satellite to the VRS grid point based on the virtual coordinates through the satellite ephemeris and the coordinates of the VRS grid point, obtaining a second distance from each satellite to the observation station based on the observation data through the satellite observation value of the VRS grid point, calculating an error between the first distance and the second distance for each satellite, wherein the error also comprises a receiver clock error, and subtracting the average value of the difference values of the first distance and the second distance of all satellites to be regarded as the difference value of the distance of a single satellite. If the deviation of the difference value of the distance of the single satellite is within the set range, the satellite data meets the consistency requirement, and the satellite data which does not meet the consistency requirement is removed. .

The calculation of the first distance Pi from the ith satellite to the survey station based on the virtual coordinates comprises:

wherein X_s,Y_s,Z_sIs the satellite coordinates obtained from the satellite ephemeris in the VRS grid data, X, Y, Z are the previously known VRS station coordinates, dt_RIs the clock difference, dt, of the station-finding receiver_SIs the satellite's clock error obtained from the satellite ephemeris in the VRS grid data, and c is the speed of light.

This is where only the clock offset of the station receiver is an unknown value, but the value is the same for all satellites, and when calculating the first range, the value is set to 0, i.e. there is a reference deviation for the first ranges of all satellites. The reference bias calculation method is as described above in point 4, calculating the difference di between the first and second distances for all satellites, and then calculating the average of di, which is considered the reference bias. If the difference between the error of the first distance and the second distance of a certain satellite and di is within a set range, the consistency requirement is met, otherwise, the consistency requirement is not met. And eliminating satellite data which does not meet the consistency requirement.

The pseudoranges, i.e., second ranges, from each satellite to the rover station are decoded from the virtual grid point data.

For a complete set of virtual reference station data, the pseudoranges and carrier phase observations for each satellite are included, along with the virtual coordinates of the virtual reference station. Theoretically, the geometric model should be consistent between the observed data and the virtual coordinates. The satellite-ground approximate distance can be calculated according to the satellite coordinates calculated by the broadcast ephemeris and the virtual reference station coordinates, and after angular errors such as satellite clock error, relative effect error and the like are deducted, the receiver clock error is simply and averagely eliminated. And comparing the residual error with the observation data of the virtual reference station, wherein the theoretical error of the residual error is in a meter-level range, and the observation data far beyond a reasonable threshold value can be regarded as abnormal observation data.

And the output module is used for coding the VRS grid point data transmitted by the gross error detection module and then pushing the coded VRS grid point data to a corresponding positioning terminal. And after the processing, the trusted data meeting the checking standard is recoded into a standard format and then is sent out for the user to use.

In another aspect, a VRS grid point zero trust checking method is provided, which, in conjunction with fig. 3, includes:

(1) VRS grid point data generated by a CORS computing system is received.

(2) And decoding the VRS grid point data and intercepting illegal messages. And further, according to the security dictionary of the RTCM data, eliminating VRS grid point data which does not conform to the format specification and is not defined in the security dictionary.

(3) Detecting whether the decoded VRS grid data comprises minimum data required by CORS service, if yes, entering the step (4), and if not, discarding; the minimum data required to provide the CORS service includes: satellite ephemeris, satellite observations, and VRS station coordinates.

(4) And (5) judging whether the consistency of the observation data of the VRS grid points and the geometric model of the virtual coordinates meets the requirement, if so, entering the step (5), and if not, discarding.

Judging whether the VRS grid data detection observation data is consistent with the geometric model of the virtual coordinate or not, comprising the following steps: and (3) obtaining a first distance from each satellite to the measuring station based on the virtual coordinates through satellite ephemeris and VRS station coordinate settlement, directly decoding VRS grid data to obtain a second distance from each satellite to the measuring station, calculating an error between the first distance and the second distance for each satellite, deducting the reference deviation of the receiver clock error, wherein if the reference deviation is within a set range, the satellite data meets the consistency requirement, and the satellite data which does not meet the consistency requirement is eliminated.

The calculation of the first distance Pi from the ith satellite to the survey station based on the virtual coordinates comprises:

wherein X_s,Y_s,Z_sIs the satellite coordinates obtained from the satellite ephemeris in the VRS grid data, X, Y, Z are the previously known VRS station coordinates, dt_RIs the clock difference, dt, of the station-finding receiver_SIs the satellite's clock error obtained from the satellite ephemeris in the VRS grid data, and c is the speed of light.

This is where only the clock offset of the station receiver is unknown, but the value is the same for all satellites, and is set to 0 when calculating the first range, i.e. there will be a same reference offset for the first ranges of all satellites. The reference deviation determination method is as follows:

the difference di between the first and second distances of all satellites is first calculated and then the average of di is calculated, which can be considered the reference deviation. And finally, obtaining the gross error of each satellite as follows:

where di is the difference between the first distance and the second distance for the ith satellite.

(5) And encoding the VRS grid point data and then pushing the encoded VRS grid point data to the corresponding positioning terminal.

In summary, the present invention relates to a VRS grid point zero trust checking system and method, which receives VRS grid point data generated by a CORS computing system; decoding VRS grid data and intercepting illegal messages; detecting the decoded VRS grid data and eliminating data which can not provide CORS service; eliminating data which are not satisfied with the requirement on the consistency of the observation data of the VRS grid points and the geometric model of the virtual coordinate; and encoding the VRS grid point data and then pushing the encoded VRS grid point data to the corresponding positioning terminal. The invention realizes the safe and rapid checking of the VRS data and improves the safety and reliability of the data; satellite data with accuracy errors not meeting requirements are eliminated, and data accuracy and reliability are guaranteed. The gross error checking of the invention is quick and effective, and avoids occupying a large amount of computing resources.

It is to be understood that the above-described embodiments of the present invention are merely illustrative of or explaining the principles of the invention and are not to be construed as limiting the invention. Therefore, any modification, equivalent replacement, improvement and the like made without departing from the spirit and scope of the present invention should be included in the protection scope of the present invention. Further, it is intended that the appended claims cover all such variations and modifications as fall within the scope and boundaries of the appended claims or the equivalents of such scope and boundaries.