CN101839986B - Satellite navigation monitoring method and system based on LAAS (Local Area Augmentation System) and WAAS (Wide Area Augmentation System) - Google Patents

Abstract

The present invention provides a satellite navigation monitoring method and system based on LAAS and WAAS, the method comprises LAAS receivers receiving navigation satellite signals, WAAS receivers receiving wide area augmentation system signals; Navigation satellite signals and wide-area augmentation system signals; and according to the navigation satellite signals and wide-area augmentation system signals, obtain the local pseudo-range correction value and wide-area pseudo-range correction value of each positioning satellite; Pseudorange correction value and wide-area pseudorange correction value, respectively obtain the estimated wide-area correction error value of each positioning satellite; and carry the estimated wide-area error correction value of each positioning satellite in the local navigation parameters and broadcast to the airborne The user device is used for the airborne user device to judge the availability of the satellite navigation device according to the received local area navigation parameters.

Description

Satellite Navigation Monitoring Method and System Based on LAAS and WAAS

technical field

Embodiments of the present invention relate to satellite navigation technology, and in particular to a satellite navigation monitoring method and system based on LAAS and WAAS. the

Background technique

Existing satellite navigation systems can be divided into Wide Area Augmentation System (WAAS for short) and Local Area Augmentation System (LAAS for short) in terms of coverage. Among them, WAAS is used to distinguish the error sources of the Global Positioning System (Global Positioning System; GPS) observations, and to "model" each error source, and then calculate the error source of each error source The error correction value is broadcast to the user through the data communication link, so that the user's receiver corrects the observation error according to the received error correction value, so as to weaken the influence of the error source and improve the accuracy of user positioning. the

LAAS mainly includes ground reference stations, airborne differential GPS receivers and data links. LASS is mainly installed in the airport area for precision approach and landing of aircraft. Among them, LAAS uses data quality monitoring (Data Quality Monitoring; abbreviation: DQM), measurement quality monitoring (Measurement Quality Monitoring; abbreviation: MQM) and signal quality monitoring (Signal QualityMonitoring; abbreviation: SQM), and a series of measures such as two-stage monitoring and execution judgment (ExecutiveMonitoring; abbreviation: EXM). As a result, under normal circumstances, the positioning accuracy of LAAS has been greatly improved, and the integrity, continuity and availability have also reached the standard of service level C (GSL C) or even service level E (GSL E). the

However, although the accuracy of WAAS meets Category I precision approach (CAT I), it cannot meet Category II precision approach (CAT II) and Category III precision approach (CAT III), and its integrity cannot meet Category I precision approach. Approach (CAT I); at the same time, the monitoring range of LAAS is limited, especially when the ionospheric anomaly occurs, the performance of LAAS will be greatly reduced. the

Contents of the invention

Embodiments of the present invention provide a satellite navigation monitoring method and system based on LAAS and WAAS, so as to increase the monitoring range of the satellite navigation system, thereby improving the ability to resist ionospheric storms. the

The embodiment of the present invention provides a kind of satellite navigation monitoring method based on LAAS and WAAS, comprising:

The LAAS receiver receives navigation satellite signals, and the WAAS receiver receives wide area augmentation system signals;

The satellite navigation monitoring device respectively acquires the navigation satellite signal and the wide area augmentation system signal received by each receiver;

The satellite navigation monitoring device obtains the local pseudo-range correction value and the wide-area pseudo-range correction value of each positioning satellite respectively according to the navigation satellite signal and the wide-area augmentation system signal;

The satellite navigation monitoring device obtains the estimated wide-area correction error value of each of the positioning satellites respectively according to the local pseudo-range correction value and the wide-area pseudo-range correction value of each of the positioning satellites;

The satellite navigation monitoring device carries the estimated wide-area correction error value of each positioning satellite in the local navigation parameters and broadcasts it to the airborne user device, so that the airborne user device can Domain navigation parameters determine the availability of the satellite navigation device. the

An embodiment of the present invention provides a satellite navigation monitoring system based on LAAS and WAAS, including a LAAS receiver, a WAAS receiver, a satellite navigation monitoring device and an airborne user device, wherein,

The LAAS receiver is used to receive navigation satellite signals, and the WAAS receiver is used to receive wide area augmentation system signals;

The satellite navigation monitoring device includes:

The signal acquisition module is used to obtain the navigation satellite signal and the wide area enhancement system signal received by each receiver respectively;

The correction value acquisition module is used for according to the navigation satellite signal and the wide area enhancement system signal,

Obtain the local pseudo-range correction value and wide-area pseudo-range correction value of each positioning satellite respectively;

The estimated correction error value acquisition module is used to obtain the estimated wide-area correction error value of each of the positioning satellites according to the local pseudo-range correction value and the wide-area pseudo-range correction value of each of the positioning satellites;

A sending module, configured to carry the estimated wide-area correction error value of each positioning satellite in local navigation parameters and broadcast to the airborne user device, so that the airborne user device can use the received A local navigation parameter determines the availability of the satellite navigation device. the

According to the satellite navigation monitoring method and system based on LAAS and WAAS in the embodiment of the present invention, the LAAS receiver receives the navigation satellite signal, the WAAS receiver receives the wide-area augmentation system signal, and the satellite navigation monitoring device is respectively based on the navigation information obtained by each receiver. Satellite signals and wide-area augmentation system signals to obtain the local pseudo-range correction value and wide-area pseudo-range correction value of each positioning satellite; and according to the local pseudo-range correction value and wide-area pseudo-range correction value, respectively obtain the The estimated wide-area correction error value of the satellite; and the wide-area error correction value of each positioning satellite is carried in the local area navigation parameters and broadcast to the airborne user device, so that the airborne user device can judge according to the received local area navigation parameters Availability of satellite navigation devices. Since the satellite navigation device receives navigation satellite signals and wide area augmentation system signals at the same time, the estimation accuracy of the estimated wide area correction error value is improved, thereby expanding the monitoring range of the satellite navigation device, and effectively improving the ionospheric storm. resilience. the

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description These are some embodiments of the present invention. For those skilled in the art, other drawings can also be obtained according to these drawings without any creative effort. the

Fig. 1 is the flowchart of an embodiment of the satellite navigation monitoring method based on LAAS and WAAS of the present invention;

Fig. 2 is the flowchart of another embodiment of the satellite navigation monitoring method based on LAAS and WAAS of the present invention;

Fig. 3 is the structural representation of an embodiment of the satellite navigation monitoring system based on LAAS and WAAS of the present invention;

Fig. 4 is a structural diagram of another embodiment of the satellite navigation monitoring system based on LAAS and WAAS of the present invention. the

Detailed ways

In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments It is a part of embodiments of the present invention, but not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without creative efforts fall within the protection scope of the present invention. the

Fig. 1 is the flow chart of an embodiment of the satellite navigation monitoring method based on LAAS and WAAS of the present invention, as shown in Fig. 1, the method of the present embodiment comprises:

Step 101, the LAAS receiver receives navigation satellite signals, and the WAAS receiver receives Wide Area Augmentation System signals. the

In this embodiment, the receiver of the ground reference station receives the navigation satellite signal and the wide area augmentation system signal. Wherein, the navigation satellite signal may specifically include the signal transmitted by the satellite in the GPS constellation and the signal transmitted by the satellite in the Global Navigation Satellite System (GLONASS) constellation; the wide area augmentation system signal may specifically be a geostationary orbit satellite ( Geostationary Orbit (hereinafter referred to as GEO) signal transmitted by satellite. It should be noted that the receivers in the various embodiments of the present invention may include two types of receivers, one is a LAAS receiver for receiving navigation satellite signals, and the other is a WAAS receiver for receiving wide area augmentation system signals. Signal. It should be noted that the WAAS receiver can also be used to receive navigation satellite signals. Meanwhile, this embodiment does not limit the number of receivers in the ground reference station, and there may be one or more receivers. The number M of receivers in each embodiment of the present invention is usually 1-4. the

Step 102, the satellite navigation monitoring device respectively acquires the navigation satellite signal and the wide area augmentation system signal received by each receiver. the

Step 103 , the satellite navigation monitoring device respectively obtains the local pseudorange correction value and the wide area pseudorange correction value of each positioning satellite according to the navigation satellite signal and the wide area augmentation system signal. the

In this embodiment, according to the navigation satellite signal, the specific implementation method of obtaining the local pseudo-range correction value is as follows: firstly, according to the ephemeris parameters of the navigation message in the navigation satellite signal, the earth-centered earth-fixed coordinate system (Earth -Centered Earth-Fixed (ECEF for short) coordinate value, and obtain the precise position information of each receiver, and then convert the precise position information of the receiver into the ECEF coordinate value of the receiver. According to the ECEF coordinate value of the receiver and the ECEF coordinate value of the corresponding positioning satellite, the distance between each receiver and each positioning satellite corresponding to each receiver is calculated respectively. Then obtain the pseudo-range observation value and carrier phase observation value corresponding to each positioning satellite from the navigation satellite signal, and smooth the pseudo-range observation value according to the carrier phase observation value to obtain the smoothed position of each positioning satellite Pseudorange observations. Then according to the distance between each receiver and the positioning satellite corresponding to each receiver, and the smoothed pseudo-range observation value of the positioning satellite corresponding to each receiver, the distance of each positioning satellite corresponding to each receiver is obtained Local pseudorange correction value. the

In this embodiment, the specific implementation method of obtaining the wide-area pseudorange correction value according to the wide-area augmentation system signal is: according to the information of WAAS message type 10 in the wide-area augmentation system signal, the wide-area long-term clock correction of the positioning satellite is calculated Value; Calculate the wide-area tropospheric correction value of the positioning satellite according to the method and model provided in the standard of the Radio Technical Commission for Aeronautics (Radio Technical Commission for Aeronautics; RTCA for short) DO-229D; according to the WAAS message types 18 and 26 information, calculate the wide-area ionospheric correction value of the positioning satellite; calculate the wide-area fast error correction value of the positioning satellite according to the information in WAAS message types 2-5, 7, and 24, and calculate the wide-area long-term clock correction value, wide-area tropospheric The correction value, the wide-area ionospheric correction value and the wide-area fast error correction value are added to obtain the wide-area pseudorange correction value. the

It should be noted that the ground reference station can select observable satellites from the global navigation satellite system as positioning satellites. This embodiment does not limit the number of positioning satellites, and there can be one positioning satellite or multiple positioning satellites. There may be N positioning satellites in each embodiment of the present invention, and N may specifically be 5-8. the

Step 104 , the satellite navigation monitoring device respectively obtains the estimated wide-area correction error value of each positioning satellite according to the local pseudo-range correction value and the wide-area pseudo-range correction value of each positioning satellite. the

In this embodiment, since the wide-area pseudorange correction value is the wide-area fast error correction value of the positioning satellite, the wide-area long-term clock correction value, the wide-area troposphere correction value, the wide-area ionosphere correction value and the wide-area fast error Therefore, according to the local pseudo-range correction value and the wide-area pseudo-range correction value, the ionospheric storm has been monitored in the calculated estimated wide-area correction error value, so that the satellite navigation Compared with the monitoring range of LAAS, the monitoring range of the device is expanded, thereby effectively improving the estimation accuracy of the estimated wide-area correction error value, and improving the ability to resist ionospheric storms. the

Step 105, the satellite navigation monitoring device carries the estimated wide-area correction error value of each positioning satellite in the local navigation parameters and broadcasts to the airborne user device, so that the airborne user device can judge the satellite navigation device according to the received local navigation parameters availability. the

In this embodiment, the local navigation parameters may include the standard deviation of the local pseudorange correction value, the ionospheric spatial gradient, the tropospheric divergence coefficient, and the effective range of the navigation system. Specifically, the ground monitoring protection level includes the vertical ground monitoring protection level and the lateral ground monitoring protection level. The alarm threshold includes vertical alarm threshold and lateral alarm threshold. Taking the vertical direction as an example, the vertical ground monitoring protection level is compared with the vertical warning threshold, and when the obtained comparison result is that the vertical ground monitoring protection level is less than the vertical warning threshold, it is determined that the satellite navigation device is in normal operation. When the obtained comparison result is that the vertical ground monitoring protection level is greater than the vertical warning threshold, the satellite navigation device will issue an alarm so that the airborne user activates other satellite navigation devices. the

In this embodiment, the navigation satellite signal is received by the LAAS receiver, the WAAS receiver receives the wide area augmentation system signal, and the satellite navigation monitoring device respectively obtains the navigation satellite signal and the wide area augmentation system signal of each receiver respectively The local pseudo-range correction value and the wide-area pseudo-range correction value of each positioning satellite, and according to the local pseudo-range correction value and the wide-area pseudo-range correction value, respectively obtain the estimated wide-area correction error value of each positioning satellite; And carrying the wide-area error correction value of each positioning satellite in the local area navigation parameters and broadcasting to the airborne user device, so that the airborne user device can judge the availability of the satellite navigation device according to the received local area navigation parameters. Since the satellite navigation device receives navigation satellite signals and wide area augmentation system signals at the same time, the estimation accuracy of the estimated wide area correction error value is improved, thereby expanding the monitoring range of the satellite navigation device, and effectively improving the ionospheric storm. resilience. the

Further, Fig. 2 is a flowchart of another embodiment of the satellite navigation monitoring method based on LAAS and WAAS of the present invention, as shown in Fig. 2, a specific implementation of the satellite navigation monitoring method of the present invention is:

Step 201, the LAAS receiver receives navigation satellite signals, and the WAAS receiver receives wide area augmentation system signals. the

Step 202, the satellite navigation monitoring device respectively acquires the navigation satellite signal and the wide area augmentation system signal received by each receiver. the

Step 203, the satellite navigation monitoring device acquires the distance of the positioning satellite corresponding to the receiver

需要说明的是，根据导航卫星信号中的导航电文的星历参数计算N颗定位卫星的ECEF坐标值存在误差，同时获取的接收机的精确位置也会存在微小测量误差，因此，定位卫星和接收机之间的距离 

并不是每个接收机和每个接收机对应的每颗定位卫星的真实距离。  Specifically, calculate the ECEF coordinate values of N positioning satellites according to the ephemeris parameters of the navigation message in the navigation satellite signal, and obtain the precise position information of each receiver, and then convert the precise position information of the receiver into the receiver's ECEF coordinate value. According to the ECEF coordinate value of each receiver and the ECEF coordinate value of each positioning satellite corresponding to each receiver, the distance between each receiver and each positioning satellite corresponding to each receiver is calculated respectively

It should be noted that there is an error in calculating the ECEF coordinates of N positioning satellites based on the ephemeris parameters of the navigation message in the navigation satellite signal, and at the same time, there will be a small measurement error in the precise position of the receiver. Therefore, the positioning satellite and receiving distance between machines

It is not the true distance between each receiver and each positioning satellite corresponding to each receiver.

Step 204, according to the navigation satellite signal, obtain the local pseudo-range observation value and the local area carrier observation value of each positioning satellite respectively, and apply the formula (1):

${{\mathrm{<span\; class="notranslate">\; R</span>}}_{\mathrm{<span\; class="notranslate">\; the\; si</span>}}}^{\mathrm{<span\; class="notranslate">\; j</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; 1</span>}}{{\mathrm{<span\; class="notranslate">\; N</span>}}_{\mathrm{<span\; class="notranslate">\; the\; s</span>}}}{\mathrm{<span\; class="notranslate">\; R</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}^{\mathrm{<span\; class="notranslate">\; j</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; +</span>\frac{{\mathrm{<span\; class="notranslate">\; N</span>}}_{\mathrm{<span\; class="notranslate">\; the\; s</span>}}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{{\mathrm{<span\; class="notranslate">\; N</span>}}_{\mathrm{<span\; class="notranslate">\; the\; s</span>}}}<span\; class="notranslate">\; (</span>{{\mathrm{<span\; class="notranslate">\; R</span>}}_{\mathrm{<span\; class="notranslate">\; the\; si</span>}}}^{\mathrm{<span\; class="notranslate">\; j</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; \&phi;</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}^{\mathrm{<span\; class="notranslate">\; j</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; \&phi;</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}^{\mathrm{<span\; class="notranslate">\; j</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; )</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span>$

Obtain the smoothed local pseudorange observations of each positioning satellite respectively

τ_s表示滤波时间常数，T_s表示局域伪距观测值的测量间隔； 表示局域伪距观测值， 表示局域载波观测值；M表示接收机个数，1≤i≤M；N表示表示定位卫星颗数，1≤j≤N；  where k represents the epoch,

τ _s represents the filtering time constant, and T _s represents the measurement interval of local pseudorange observations; Represents the local pseudorange observations, Indicates local carrier observation value; M indicates the number of receivers, 1≤i≤M; N indicates the number of positioning satellites, 1≤j≤N;

和定位卫星的平滑后的局域伪距观测值 

应用公式(2)：  Step 205, according to the distance

and the smoothed local pseudorange observations of the positioning satellite

Apply formula (2):

${\mathrm{<span\; class="notranslate">\; PR</span>}}_{\mathrm{<span\; class="notranslate">\; Li</span>}}^{\mathrm{<span\; class="notranslate">\; j</span>}}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; R</span>}}_{\mathrm{<span\; class="notranslate">\; turei</span>}}^{\mathrm{<span\; class="notranslate">\; j</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; R</span>}}_{\mathrm{<span\; class="notranslate">\; the\; si</span>}}^{\mathrm{<span\; class="notranslate">\; j</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 2</span>}<span\; class="notranslate">\; )</span>$

Obtain the local pseudorange correction value of each positioning satellite separately

Step 206: According to the wide-area long-term clock correction value, wide-area troposphere correction value, wide-area ionosphere correction value and wide-area fast error correction value obtained from the wide-area augmentation system signal, respectively obtain the wide-area pseudorange of each positioning satellite correction value

和广域伪距校正值 

采用公式(3)：  Step 207, according to the local pseudo-range correction value of the positioning satellite

and wide-area pseudorange correction values

Using formula (3):

${\stackrel{<span\; class="notranslate">\; ^</span>}{\mathrm{<span\; class="notranslate">\; \&delta;</span>}}}_{\mathrm{<span\; class="notranslate">\; i</span>}}^{\mathrm{<span\; class="notranslate">\; j</span>}}<span\; class="notranslate">\; =</span>{{\mathrm{<span\; class="notranslate">\; PR</span>}}_{\mathrm{<span\; class="notranslate">\; wi</span>}}}^{\mathrm{<span\; class="notranslate">\; j</span>}}<span\; class="notranslate">\; -</span>{{\mathrm{<span\; class="notranslate">\; PR</span>}}_{\mathrm{<span\; class="notranslate">\; Li</span>}}}^{\mathrm{<span\; class="notranslate">\; j</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 3</span>}<span\; class="notranslate">\; )</span>$

Obtain the estimated wide-area correction error value of each positioning satellite separately

以及接收机钟差估值 

则局域伪距校正值 

还可以如公式(4)所示：  In this embodiment, assuming that the real pseudorange correction value is T _i ^j , the measurement noise of local monitoring is

and receiver clock bias estimates

Then the local pseudorange correction value

It can also be shown in formula (4):

${{\mathrm{<span\; class="notranslate">\; PR</span>}}_{\mathrm{<span\; class="notranslate">\; Li</span>}}}^{\mathrm{<span\; class="notranslate">\; j</span>}}<span\; class="notranslate">\; =</span>{{\mathrm{<span\; class="notranslate">\; T</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}}^{\mathrm{<span\; class="notranslate">\; j</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; b</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}^{\mathrm{<span\; class="notranslate">\; j</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; \&epsiv;</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}^{\mathrm{<span\; class="notranslate">\; j</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 4</span>}<span\; class="notranslate">\; )</span>$

是相同的，因此可以设 

又由于该接收机钟差估值 

为用户可以通过对N颗定位卫星的伪距差值取平均得到，因此，还可以设LAAS接收机钟差估值 

为0，从而使公式(4)变为公式(5)：  For a receiver, the LAAS receiver clock error estimation of the N positioning satellites received by the receiver

are the same, so we can set

And since the receiver clock bias estimate

For the user, it can be obtained by averaging the pseudo-range differences of N positioning satellites, therefore, the LAAS receiver clock error estimation can also be set

is 0, so that formula (4) becomes formula (5):

${\mathrm{<span\; class="notranslate">\; PR</span>}}_{\mathrm{<span\; class="notranslate">\; Li</span>}}^{\mathrm{<span\; class="notranslate">\; j</span>}}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; T</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}^{\mathrm{<span\; class="notranslate">\; j</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; \&epsiv;</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}^{\mathrm{<span\; class="notranslate">\; j</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 5</span>}<span\; class="notranslate">\; )</span>$

还可以如公式(6)所示：  In addition, for the wide-area pseudorange correction value

It can also be shown in formula (6):

${\mathrm{<span\; class="notranslate">\; PR</span>}}_{\mathrm{<span\; class="notranslate">\; wi</span>}}^{\mathrm{<span\; class="notranslate">\; j</span>}}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; T</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}^{\mathrm{<span\; class="notranslate">\; j</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}^{\mathrm{<span\; class="notranslate">\; j</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; \&delta;</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}^{\mathrm{<span\; class="notranslate">\; j</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 6</span>}<span\; class="notranslate">\; )</span>$

为真实广域校正误差值； 

为WAAS接收机钟差估值。对于某一接收机而言，该接收机接收到的N颗定位卫星的WAAS接收机钟差估值 

是相同的，因此可以设 

又由于该WAAS接收机钟差估值 为用户可以通过对N颗定位卫星的伪距差值取平均得到，因此，还可以设接收机钟差估值 

为0，从而使公式(6)变为公式(7)：  in,

Correct the error value for the real wide area;

Estimated clock bias for WAAS receivers. For a certain receiver, the WAAS receiver clock error estimation of the N positioning satellites received by the receiver

are the same, so we can set

And since the WAAS receiver clock bias estimates For the user, it can be obtained by averaging the pseudorange differences of N positioning satellites, therefore, the receiver clock error estimation can also be set

is 0, so that formula (6) becomes formula (7):

${\mathrm{<span\; class="notranslate">\; PR</span>}}_{\mathrm{<span\; class="notranslate">\; wi</span>}}^{\mathrm{<span\; class="notranslate">\; j</span>}}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; T</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}^{\mathrm{<span\; class="notranslate">\; j</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; \&delta;</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}^{\mathrm{<span\; class="notranslate">\; j</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 7</span>}<span\; class="notranslate">\; )</span>$

According to the formulas (3), (5) and (7), the formula (8) is calculated:

${\mathrm{<span\; class="notranslate">\; \&delta;</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}^{\mathrm{<span\; class="notranslate">\; j</span>}}<span\; class="notranslate">\; =</span>{\stackrel{<span\; class="notranslate">\; ^</span>}{\mathrm{<span\; class="notranslate">\; \&delta;</span>}}}_{\mathrm{<span\; class="notranslate">\; i</span>}}^{\mathrm{<span\; class="notranslate">\; j</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; \&epsiv;</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}^{\mathrm{<span\; class="notranslate">\; j</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 8</span>}<span\; class="notranslate">\; )</span>$

和估计广域校正误差值 

组成的。同时，假设测量噪声 服从均值为0、局域伪距校正值的标准偏差 

的高斯分布前提下，则真实广域校正误差值 

和估计广域校正误差值 满足：  Based on the above analysis, it can be seen that the real wide-area correction error value is caused by the measurement noise

and estimated wide-area corrected error values

consist of. Also, assuming the measurement noise Subject to mean 0, standard deviation of local pseudorange correction values

Under the premise of the Gaussian distribution of , the real wide-area correction error value

and estimated wide-area corrected error values satisfy:

$\mathrm{<span\; class="notranslate">\; P</span>}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; \&delta;</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}^{\mathrm{<span\; class="notranslate">\; j</span>}}<span\; class="notranslate">\; |</span>{\stackrel{<span\; class="notranslate">\; ^</span>}{\mathrm{<span\; class="notranslate">\; \&delta;</span>}}}_{\mathrm{<span\; class="notranslate">\; i</span>}}^{\mathrm{<span\; class="notranslate">\; j</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; N</span>}<span\; class="notranslate">\; (</span>{\stackrel{<span\; class="notranslate">\; ^</span>}{\mathrm{<span\; class="notranslate">\; \&delta;</span>}}}_{\mathrm{<span\; class="notranslate">\; i</span>}}^{\mathrm{<span\; class="notranslate">\; j</span>}}<span\; class="notranslate">\; ,</span>{\mathrm{<span\; class="notranslate">\; \&sigma;</span>}}_{\mathrm{<span\; class="notranslate">\; Li</span>}}^{\mathrm{<span\; class="notranslate">\; j</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 9</span>}<span\; class="notranslate">\; )</span>$

如公式(10)所示：  in,

As shown in formula (10):

${\mathrm{<span\; class="notranslate">\; \&sigma;</span>}}_{\mathrm{<span\; class="notranslate">\; Li</span>}}^{\mathrm{<span\; class="notranslate">\; j</span>}}<span\; class="notranslate">\; =</span>\sqrt{\frac{{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; a</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; a</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; e</span>}}^{<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; \&theta;</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}^{\mathrm{<span\; class="notranslate">\; j</span>}}<span\; class="notranslate">\; /</span>{\mathrm{<span\; class="notranslate">\; \&theta;</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; 2</span>}}}{\mathrm{<span\; class="notranslate">\; m</span>}}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; a</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; +</span>{<span\; class="notranslate">\; (</span>\frac{{\mathrm{<span\; class="notranslate">\; a</span>}}_{\mathrm{<span\; class="notranslate">\; 3</span>}}}{\mathrm{<span\; class="notranslate">\; sin</span>}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; \&theta;</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}^{\mathrm{<span\; class="notranslate">\; j</span>}}<span\; class="notranslate">\; )</span>}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 10</span>}<span\; class="notranslate">\; )</span>$

Among them, a ₀ , a ₁ , a ₂ , a ₃ and θ ₀ represent parameters related to receiver performance.

携带在局域导航参数中播发给机载用户装置，以供机载用户装置根据接收到的局域导航参数判断卫星导航装置的可用性。  Step 208, the estimated wide-area correction error value of each positioning satellite

carried in the local area navigation parameters and broadcast to the airborne user device, so that the airborne user device can judge the availability of the satellite navigation device according to the received local area navigation parameters.

Further, step 208 includes:

Step 2081. Obtain the ground monitoring protection level according to the local area navigation parameters. the

Specifically, the ground monitoring protection level includes the vertical ground monitoring protection level and the lateral ground monitoring protection level. Among them, a specific implementation method of the vertical ground monitoring protection level and the lateral ground monitoring protection level is:

According to the local navigation parameters, and using the formula (11):

${\mathrm{<span\; class="notranslate">\; VPL</span>}}_{\mathrm{<span\; class="notranslate">\; WLS</span>}}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; K</span>}\sqrt{\underset{\mathrm{<span\; class="notranslate">\; j</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\overset{\mathrm{<span\; class="notranslate">\; N</span>}}{\mathrm{<span\; class="notranslate">\; \&Sigma;</span>}}}{\mathrm{<span\; class="notranslate">\; S</span>}}_{\mathrm{<span\; class="notranslate">\; v</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; j</span>}<span\; class="notranslate">\; )</span>{\mathrm{<span\; class="notranslate">\; \&sigma;</span>}}_{\mathrm{<span\; class="notranslate">\; tot</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; j</span>}<span\; class="notranslate">\; )</span>}<span\; class="notranslate">\; +</span><span\; class="notranslate">\; |</span>\underset{\mathrm{<span\; class="notranslate">\; j</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\overset{\mathrm{<span\; class="notranslate">\; N</span>}}{\mathrm{<span\; class="notranslate">\; \&Sigma;</span>}}}{\mathrm{<span\; class="notranslate">\; S</span>}}_{\mathrm{<span\; class="notranslate">\; v</span>}}<span\; class="notranslate">\; (</span>\text{<span class="notranslate"> j</span>}<span\; class="notranslate">\; )</span>{\mathrm{<span\; class="notranslate">\; \&delta;</span>}}_{\mathrm{<span\; class="notranslate">\; j</span>}}^{<span\; class="notranslate">\; \$</span>}<span\; class="notranslate">\; |</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 11</span>}<span\; class="notranslate">\; )</span>$

Obtain vertical protection level VPL _WLS for satellite navigation devices;

为M个接收机的估计广域校正误差值的平均值。  Among them, K is the error amplification factor; N is the number of positioning satellites; S _v (j) represents a conversion matrix from the pseudo-local domain to the positioning domain; σ _tot (j) is the total calculated by the user for the jth positioning satellite standard deviation;

is the average of estimated wide-area correction error values for M receivers.

Specifically, the specific calculation method of the error amplification factor K is:

Applying formula (12) and formula (13):

K＝Q ^-1 (P _HMI-ff /2) (12)

$\mathrm{<span\; class="notranslate">\; Q</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; x</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; 1</span>}}{\sqrt{\mathrm{<span\; class="notranslate">\; 2</span>}\mathrm{<span\; class="notranslate">\; \&pi;</span>}}}{<span\; class="notranslate">\; \&Integral;</span>}_{\mathrm{<span\; class="notranslate">\; x</span>}}^{<span\; class="notranslate">\; \&infin;</span>}{\mathrm{<span\; class="notranslate">\; e</span>}}^{<span\; class="notranslate">\; -</span>\frac{{\mathrm{<span\; class="notranslate">\; t</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}}{\mathrm{<span\; class="notranslate">\; 2</span>}}}\mathrm{<span\; class="notranslate">\; dt</span>}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 13</span>}<span\; class="notranslate">\; )</span>$

Get the error amplification factor K. Among them, P _HMI-ff is the integrity risk value when the ground reference station has no receiver failure. This value may adopt the value provided in DO-245A of the Minimum Aviation System Performance Standards (MASPS for short) of LAAS.

The calculation method of the conversion matrix S _v (j) from the pseudo-local domain to the positioning domain is:

Apply formula (14):

S _v (j)＝S _z (j)+S _x (j)*tanθ _GS (14)

Obtain the transformation matrix S _v (j) from the pseudo-local domain to the localization domain. Among them, S _z (j) and S _x (j) represent the j-th column elements in the S matrix related to the z direction and the x direction, respectively, and θ _GS is the approach glide angle.

The expression formula of σ _tot (j) can be shown as formula (15):

${\mathrm{<span\; class="notranslate">\; \&sigma;</span>}}_{\mathrm{<span\; class="notranslate">\; tot</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; j</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; =</span>{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; \&sigma;</span>}}_{\mathrm{<span\; class="notranslate">\; Lj</span>}}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; +</span>{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; \&sigma;</span>}}_{\mathrm{<span\; class="notranslate">\; the\; air</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; j</span>}}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; +</span>{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; \&sigma;</span>}}_{\mathrm{<span\; class="notranslate">\; iono</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; j</span>}}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; +</span>{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; \&sigma;</span>}}_{\mathrm{<span\; class="notranslate">\; trop</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; j</span>}}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 15</span>}<span\; class="notranslate">\; )</span>$

的平均值，如公式(16)所示：  Among them, σ _{air, j} refers to the standard deviation of multipath and thermal noise errors; σ _{iono, j} refers to the standard deviation of ionospheric errors; σ _{trop, j} refers to the standard deviation of tropospheric errors, and their specific calculation formulas can refer to MASPS of LAAS DO-245A. σ _Lj is the

The average value of , as shown in formula (16):

${\mathrm{<span\; class="notranslate">\; \&sigma;</span>}}_{\mathrm{<span\; class="notranslate">\; Lj</span>}}<span\; class="notranslate">\; =</span>\frac{\underset{\mathrm{<span\; class="notranslate">\; i</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\overset{\mathrm{<span\; class="notranslate">\; m</span>}}{\mathrm{<span\; class="notranslate">\; \&Sigma;</span>}}}{\mathrm{<span\; class="notranslate">\; \&sigma;</span>}}_{\mathrm{<span\; class="notranslate">\; Li</span>}}^{\mathrm{<span\; class="notranslate">\; j</span>}}}{\mathrm{<span\; class="notranslate">\; m</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 16</span>}<span\; class="notranslate">\; )</span>$

如公式(10)所示： 

As shown in formula (10):

${\mathrm{<span\; class="notranslate">\; \&sigma;</span>}}_{\mathrm{<span\; class="notranslate">\; Li</span>}}^{\mathrm{<span\; class="notranslate">\; j</span>}}<span\; class="notranslate">\; =</span>\sqrt{\frac{{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; a</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; a</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; e</span>}}^{<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; \&theta;</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}^{\mathrm{<span\; class="notranslate">\; j</span>}}<span\; class="notranslate">\; /</span>{\mathrm{<span\; class="notranslate">\; \&theta;</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; 2</span>}}}{\mathrm{<span\; class="notranslate">\; m</span>}}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; a</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; +</span>{<span\; class="notranslate">\; (</span>\frac{{\mathrm{<span\; class="notranslate">\; a</span>}}_{\mathrm{<span\; class="notranslate">\; 3</span>}}}{\mathrm{<span\; class="notranslate">\; sin</span>}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; \&theta;</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}^{\mathrm{<span\; class="notranslate">\; j</span>}}<span\; class="notranslate">\; )</span>}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 10</span>}<span\; class="notranslate">\; )</span>$

Among them, a ₀ , a ₁ , a ₂ , a ₃ and θ ₀ represent parameters related to receiver performance.

如公式(17)所示：  Average of estimated wide-area correction error values for M receivers

As shown in formula (17):

${\stackrel{<span\; class="notranslate">\; ^</span>}{\mathrm{<span\; class="notranslate">\; \&delta;</span>}}}_{\mathrm{<span\; class="notranslate">\; j</span>}}<span\; class="notranslate">\; =</span>\frac{\underset{\mathrm{<span\; class="notranslate">\; i</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\overset{\mathrm{<span\; class="notranslate">\; m</span>}}{\mathrm{<span\; class="notranslate">\; \&Sigma;</span>}}}{\stackrel{<span\; class="notranslate">\; ^</span>}{\mathrm{<span\; class="notranslate">\; \&delta;</span>}}}_{\mathrm{<span\; class="notranslate">\; i</span>}}^{\mathrm{<span\; class="notranslate">\; j</span>}}}{\mathrm{<span\; class="notranslate">\; m</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 17</span>}<span\; class="notranslate">\; )</span>$

According to the local navigation parameters, and adopt the formula (18):

${\mathrm{<span\; class="notranslate">\; LPL</span>}}_{\mathrm{<span\; class="notranslate">\; WLS</span>}}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; K</span>}\sqrt{\underset{\mathrm{<span\; class="notranslate">\; j</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\overset{\mathrm{<span\; class="notranslate">\; N</span>}}{\mathrm{<span\; class="notranslate">\; \&Sigma;</span>}}}{\mathrm{<span\; class="notranslate">\; S</span>}}_{\mathrm{<span\; class="notranslate">\; L</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; j</span>}<span\; class="notranslate">\; )</span>{\mathrm{<span\; class="notranslate">\; \&sigma;</span>}}_{\mathrm{<span\; class="notranslate">\; tot</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; j</span>}<span\; class="notranslate">\; )</span>}<span\; class="notranslate">\; +</span><span\; class="notranslate">\; |</span>\underset{\mathrm{<span\; class="notranslate">\; j</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\overset{\mathrm{<span\; class="notranslate">\; N</span>}}{\mathrm{<span\; class="notranslate">\; \&Sigma;</span>}}}{\mathrm{<span\; class="notranslate">\; S</span>}}_{\mathrm{<span\; class="notranslate">\; L</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; j</span>}<span\; class="notranslate">\; )</span>{\mathrm{<span\; class="notranslate">\; \&delta;</span>}}_{\mathrm{<span\; class="notranslate">\; j</span>}}^{<span\; class="notranslate">\; \$</span>}<span\; class="notranslate">\; |</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 18</span>}<span\; class="notranslate">\; )</span>$

Get Lateral Protection Level LPL _WLS for Sat Nav.

Among them, the calculation method of the transformation matrix S _L (j) from the pseudo-local domain to the positioning domain is:

Apply formula (19):

S _L (j) = S _y (j) (19)

Obtain the transformation matrix S _L (j) from the pseudo-local domain to the localization domain. Wherein, S _y (j) represents the jth column element related to the y direction in the S matrix.

According to the local navigation parameters, and adopt the formula (20):

${\mathrm{<span\; class="notranslate">\; VEB</span>}}_{\mathrm{<span\; class="notranslate">\; j</span>}}<span\; class="notranslate">\; =</span><span\; class="notranslate">\; |</span>{\mathrm{<span\; class="notranslate">\; S</span>}}_{\mathrm{<span\; class="notranslate">\; v</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; j</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; |</span>{\mathrm{<span\; class="notranslate">\; \&chi;</span>}}_{\mathrm{<span\; class="notranslate">\; the\; air</span>}}{\mathrm{<span\; class="notranslate">\; P</span>}}_{\mathrm{<span\; class="notranslate">\; j</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; K</span>}}_{\mathrm{<span\; class="notranslate">\; md</span>}<span\; class="notranslate">\; \_</span>\mathrm{<span\; class="notranslate">\; e</span>}}\sqrt{\underset{\mathrm{<span\; class="notranslate">\; i</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\overset{\mathrm{<span\; class="notranslate">\; m</span>}}{\mathrm{<span\; class="notranslate">\; \&Sigma;</span>}}}{\mathrm{<span\; class="notranslate">\; S</span>}}_{\mathrm{<span\; class="notranslate">\; v</span>}}{<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; j</span>}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; 2</span>}}{\mathrm{<span\; class="notranslate">\; \&sigma;</span>}}_{\mathrm{<span\; class="notranslate">\; tot</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; j</span>}<span\; class="notranslate">\; )</span>}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 20</span>}<span\; class="notranslate">\; )</span>$

Obtain the vertical ephemeris protection level VEB _j of each positioning satellite;

Among them; χ _air is the distance between the airborne user device and the ground reference station, in meters; P _j is the ephemeris related parameters, which are carried in the navigation satellite parameters and broadcast to the airborne user device by the ground reference station; K The missing detection probability coefficient corresponding to the integrity risk value of _{md_e} when a single positioning satellite fails, its calculation method is the same as the calculation method of K in step 207 . I won't repeat them here.

It should be noted that the maximum value of the vertical ephemeris protection level VEB _j of each positioning satellite is the vertical ephemeris protection level VEB of the navigation satellite augmentation system, as shown in formula (21):

VEB=max(VEB _j ) (21)

According to the local navigation parameters, and adopt the formula (22):

${\mathrm{<span\; class="notranslate">\; LEB</span>}}_{\mathrm{<span\; class="notranslate">\; j</span>}}<span\; class="notranslate">\; =</span><span\; class="notranslate">\; |</span>{\mathrm{<span\; class="notranslate">\; S</span>}}_{\mathrm{<span\; class="notranslate">\; L</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; j</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; |</span>{\mathrm{<span\; class="notranslate">\; \&chi;</span>}}_{\mathrm{<span\; class="notranslate">\; the\; air</span>}}{\mathrm{<span\; class="notranslate">\; P</span>}}_{\mathrm{<span\; class="notranslate">\; j</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; K</span>}}_{\mathrm{<span\; class="notranslate">\; md</span>}<span\; class="notranslate">\; \_</span>\mathrm{<span\; class="notranslate">\; e</span>}}\sqrt{\underset{\mathrm{<span\; class="notranslate">\; i</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\overset{\mathrm{<span\; class="notranslate">\; m</span>}}{\mathrm{<span\; class="notranslate">\; \&Sigma;</span>}}}{\mathrm{<span\; class="notranslate">\; S</span>}}_{\mathrm{<span\; class="notranslate">\; L</span>}}{<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; j</span>}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; 2</span>}}{\mathrm{<span\; class="notranslate">\; \&sigma;</span>}}_{\mathrm{<span\; class="notranslate">\; tot</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; j</span>}<span\; class="notranslate">\; )</span>}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; twenty\; two</span>}<span\; class="notranslate">\; )</span>$

Obtain the lateral ephemeris protection level LEB _j of each positioning satellite;

It should be noted that the maximum value of the lateral ephemeris protection level LEB _j of each positioning satellite is the lateral ephemeris protection level LEB of the navigation satellite augmentation system, as shown in formula (23):

LEB=max(LEB _j ) (23)

According to the vertical protection level VPL _WLS of the satellite navigation device, the lateral protection level LPL _WLS of the satellite navigation device, the vertical ephemeris protection level VEB of the navigation satellite augmentation system and the lateral ephemeris protection level LEB of the navigation satellite augmentation system, and adopt the formula (24) and formula (25):

VPL=max( _VPLWLS , VEB) (24)

LPL = max(VPL _WLS , LEB) (25)

Obtain vertical ground monitoring protection level VPL and lateral ground monitoring protection level LPL. the

Step 2082, comparing the ground monitoring protection level with the preset alarm threshold, obtaining the comparison result, and judging the availability of the satellite navigation device according to the comparison result. the

Specifically, the ground monitoring protection level includes the vertical ground monitoring protection level and the lateral ground monitoring protection level. The alarm threshold includes vertical alarm threshold and lateral alarm threshold. Taking the vertical direction as an example, the vertical ground monitoring protection level is compared with the vertical warning threshold, and when the obtained comparison result is that the vertical ground monitoring protection level is less than the vertical warning threshold, it is determined that the satellite navigation device is in normal operation. When the obtained comparison result is that the vertical ground monitoring protection level is greater than the vertical warning threshold, the satellite navigation device will send out an alarm, so that the airborne is used to activate other satellite navigation devices. the

It should be noted that the method of comparing the protection level of lateral ground monitoring with the lateral warning threshold is the same as the method of comparing the protection level of vertical ground monitoring with the vertical warning threshold, and will not be repeated here. the

In this embodiment, the ground monitoring protection level is obtained according to the received local area navigation parameters, and the ground monitoring protection level is compared with the preset alarm threshold to judge the availability of the satellite navigation device according to the comparison result. Since the local navigation parameters include the estimated wide-area correction error value, the wide-area error correction value includes accurate monitoring of ionospheric storms, thereby improving the estimation accuracy of the estimated wide-area correction error value, thereby expanding the satellite navigation device monitoring range, and effectively improve the ability to resist ionospheric storms. the

Fig. 3 is the structural representation of an embodiment of the satellite navigation monitoring system based on LAAS and WAAS of the present invention, as shown in Fig. 3, the system of the present embodiment comprises: LAAS receiver 11, WAAS receiver 12, satellite navigation monitoring device 13 and On-board user equipment 14 . Among them, LAAS receiver 11 receives navigation satellite signals; WAAS receiver 12 receives Wide Area Augmentation System signals. The satellite navigation monitoring device 13 includes a signal acquisition module 131 , a correction value acquisition module 132 , an estimated correction error value acquisition module 133 and a sending module 134 . the

Specifically, the signal acquisition module 131 is used to respectively acquire the navigation satellite signal and the wide area enhancement system signal of each receiver; the correction value acquisition module 132 is used to respectively acquire each positioning satellite The local pseudo-range correction value and the wide-area pseudo-range correction value; the estimated correction error value acquisition module 133 is used to obtain the estimation of each positioning satellite respectively according to the local pseudo-range correction value and the wide-area pseudo-range correction value Wide-area correction error value; the sending module 134 is used to carry the estimated wide-area correction error value of each positioning satellite in the local navigation parameters and broadcast it to the airborne user device, so that the airborne user device Determine the availability of satellite navigation devices. the

The satellite navigation system based on LAAS and WAAS in this embodiment can be used to implement the technical solution of the method embodiment shown in FIG. 1 , and its implementation principles are similar, so details will not be repeated here. the

In this embodiment, the navigation satellite signal is received by the LAAS receiver, the WAAS receiver receives the wide area augmentation system signal, and the satellite navigation monitoring device obtains respectively according to the navigation satellite signal and the wide area augmentation system signal of each receiver obtained. The local pseudorange correction value and the wide area pseudorange correction value of each positioning satellite, and according to the local pseudorange correction value and the wide area pseudorange correction value, respectively obtain the estimated wide area correction error value of each positioning satellite; and The wide-area error correction value of each positioning satellite is carried in the local area navigation parameters and broadcast to the airborne user device, so that the airborne user device can judge the availability of the satellite navigation device according to the received local area navigation parameters. Since the satellite navigation device receives navigation satellite signals and wide area augmentation system signals at the same time, the estimation accuracy of the estimated wide area correction error value is improved, thereby expanding the monitoring range of the satellite navigation device, and effectively improving the ionospheric storm. resilience. the

Fig. 4 is the schematic structural diagram of another embodiment of the satellite navigation monitoring system based on LAAS and WAAS of the present invention, as shown in Fig. 4, on the basis of the above embodiment, the correction value acquisition module 132 includes a distance acquisition unit 1321, a smoothing processing unit 1322 , the local area pseudorange correction value acquisition unit 1323 and the wide area pseudorange correction value acquisition unit 1324 . the

平滑处理单元1322用于根据导航卫星信号，分别获取各定位卫星对应的局域伪距观测值和局域载波观测值；并应用公式 

获取每颗定位卫星的平滑后的局域伪距观测值 

局域伪距校正值获取单元1323用于根据距离 

和定位卫星对应的平滑后的局域伪距观测值 

应用公式 

分别获取各定位卫星的局域伪距校正值 

广域伪距校正值获取单元1324用于根据从广域增强系统信号中获取的广域长期时钟校正值、广域对流层校正值、广域电离层校正值和广域快速误差校正值，分别获取各定位卫星的广域伪距校正值 

Specifically, the distance acquiring unit 1321 is used to respectively acquire the distance of the positioning satellite corresponding to the receiver

The smoothing processing unit 1322 is used to obtain the local pseudorange observation value and the local area carrier observation value corresponding to each positioning satellite according to the navigation satellite signal; and apply the formula

Obtain smoothed local pseudorange observations for each positioning satellite

The local pseudorange correction value acquisition unit 1323 is used to obtain

Smoothed local pseudorange observations corresponding to positioning satellites

Apply the formula

Obtain the local pseudorange correction value of each positioning satellite separately

The wide-area pseudorange correction value acquisition unit 1324 is used to obtain the wide-area long-term clock correction value, wide-area troposphere correction value, wide-area ionosphere correction value and wide-area fast error correction value obtained from the wide-area augmentation system signal, respectively. Wide-area pseudorange correction value of each positioning satellite

和广域伪距校正值 

应用公式 

分别获取各定位卫星的估计广域校正误差值  At the same time, the estimated correction error value acquisition module 133 is used to obtain the local pseudorange correction value according to each positioning satellite

and wide-area pseudorange correction values

Apply the formula

Obtain the estimated wide-area correction error value of each positioning satellite separately

Further, the airborne user device 14 includes: a ground monitoring protection level acquisition module 141 and a comparison module 142 . Among them, the ground monitoring protection level acquisition module 141 is used to obtain the ground monitoring protection level according to the local navigation parameters; the comparison module 142 is used to compare the ground monitoring protection level with the preset alarm threshold to obtain the comparison result, and according to the comparison result Determine the availability of satellite navigation devices. the

和 

分别获取卫星导航装置的垂直保护级VPL_WLS和卫星导航装置的侧向保护级LPL_WLS；卫星导航装置星历保护级获取单元1412根据局域导航参数，并采用公式  $\left\{\begin{array}{c}{\mathrm{VEB}}_j=\left|S_v\left(j\right)\right|{\mathrm{\&chi;}}_{\mathrm{air}}{P}_j+K_{\mathrm{md}\_e}\sqrt{\underset{i=1}{\overset{M}{\mathrm{\&Sigma;}}}{S}_v{\left(j\right)}^2{\mathrm{\&sigma;}}_{\mathrm{tot}}^2\left(j\right)}\\ {\mathrm{VEB}}_j=\left|S_L\left(j\right)\right|{\mathrm{\&chi;}}_{\mathrm{air}}{P}_j+K_{\mathrm{md}\_e}\sqrt{\underset{i=1}{\overset{M}{\mathrm{\&Sigma;}}}{S}_L{\left(j\right)}^2{\mathrm{\&sigma;}}_{\mathrm{tot}}^2\left(j\right)}\end{array}\right.,$ 获取每颗定位卫星的垂直星历保护级VEB_j和获取每颗定位卫星的侧向星历保护级LEB_j；并选取定位卫星的垂直星历保护级中的最大值和定位卫星的侧向星历保护级最大值分别作为导航卫星增强系统的垂直星历保护级VEB和导航卫星增强系统的侧向星历保护级LEB；地面监测保护级获取单元1413用于根据卫星导航装置的垂直保护级VPL_WLS、卫星导航装置的侧向保护级LPL_WLS、导航卫星增强系统的垂直星历保护级VEB和导航卫星增强系统的侧向星历保护级LEB，并采用公式VPL＝max(VPL_WLS，VEB)和LPL＝max(LPL_WLS，LEB)，获取垂直地面监测保护级VPL和侧向地面监测保护级LPL。  Further, the ground monitoring protection level acquisition module 141 includes a satellite navigation device protection level acquisition unit 1411 , a satellite navigation device ephemeris protection level acquisition unit 1412 and a ground monitoring protection level acquisition unit 1413 . Wherein, the protection level acquisition unit 1411 of the satellite navigation device is based on the local navigation parameters and adopts the formula

and

Obtain the vertical protection level VPL _WLS of the satellite navigation device and the lateral protection level LPL _WLS of the satellite navigation device respectively; $\left\{\begin{array}{c}{\mathrm{VEB}}_j=\left|S_v\left(j\right)\right|{\mathrm{\&chi;}}_{\mathrm{the\; air}}{P}_j+K_{\mathrm{md}\_e}\sqrt{\underset{i=1}{\overset{m}{\mathrm{\&Sigma;}}}{S}_v{\left(j\right)}^2{\mathrm{\&sigma;}}_{\mathrm{tot}}^2\left(j\right)}\\ {\mathrm{VEB}}_j=\left|S_L\left(j\right)\right|{\mathrm{\&chi;}}_{\mathrm{the\; air}}{P}_j+K_{\mathrm{md}\_e}\sqrt{\underset{i=1}{\overset{m}{\mathrm{\&Sigma;}}}{S}_L{\left(j\right)}^2{\mathrm{\&sigma;}}_{\mathrm{tot}}^2\left(j\right)}\end{array}\right.,$ Obtain the vertical ephemeris protection level VEB _j of each positioning satellite and the lateral ephemeris protection level LEB _j of each positioning satellite; and select the maximum value of the vertical ephemeris protection level of the positioning satellite and the lateral ephemeris protection level of the positioning satellite The maximum value of the almanac protection level is respectively used as the vertical ephemeris protection level VEB of the navigation satellite augmentation system and the lateral ephemeris protection level LEB of the navigation satellite augmentation system; the ground monitoring protection level acquisition unit 1413 is used to _WLS , the lateral protection level LPL _WLS of the satellite navigation device, the vertical ephemeris protection level VEB of the navigation satellite augmentation system, and the lateral ephemeris protection level LEB of the navigation satellite augmentation system, and adopt the formula VPL=max(VPL _WLS , VEB) and LPL=max(LPL _WLS , LEB), to obtain the vertical ground monitoring protection level VPL and the lateral ground monitoring protection level LPL.

The LAAS- and WAAS-based navigation satellite monitoring system of this embodiment can be used to implement the technical solution of the method embodiment shown in FIG. 2 , and its implementation principles are similar, so details will not be repeated here. the

In this embodiment, the LAAS receiver receives navigation satellite signals from at least one LASS system positioning satellite, and the WAAS receiver receives wide area augmentation system signals from at least one WASS system positioning satellite. The navigation satellite signals and wide-area augmentation system signals of two receivers obtain the local pseudo-range correction value and wide-area pseudo-range correction value of each positioning satellite respectively, and according to the local pseudo-range correction value and wide-area pseudo-range correction value value, to obtain the estimated wide-area correction error value of each positioning satellite respectively; and carry the wide-area error correction value of each positioning satellite in the local area navigation parameters and broadcast to the airborne user device for the airborne user device to receive The obtained local navigation parameters are obtained to obtain the ground monitoring protection level, and the ground monitoring protection level is compared with the preset alarm threshold, so as to judge the availability of the satellite navigation device according to the comparison result. Since the local navigation parameters include the estimated wide-area correction error value, the wide-area error correction value includes accurate monitoring of ionospheric storms, thereby improving the estimation accuracy of the estimated wide-area correction error value, thereby expanding the satellite navigation device monitoring range, and effectively improve the ability to resist ionospheric storms. the

Those of ordinary skill in the art can understand that all or part of the steps for realizing the above-mentioned method embodiments can be completed by hardware related to program instructions, and the aforementioned program can be stored in a computer-readable storage medium. When the program is executed, the It includes the steps of the above method embodiments; and the aforementioned storage medium includes: ROM, RAM, magnetic disk or optical disk and other various media that can store program codes. the

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: it can still be Modifications are made to the technical solutions described in the foregoing embodiments, or equivalent replacements are made to some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the various embodiments of the present invention. the

Claims (10)

1. A satellite navigation monitoring method based on LAAS and WAAS is characterized by comprising the following steps:

the LAAS receiver receives a navigation satellite signal, and the WAAS receiver receives a wide area augmentation system signal;

the satellite navigation monitoring device respectively acquires navigation satellite signals and wide area augmentation system signals received by each receiver;

the satellite navigation monitoring device respectively acquires a local pseudo-range correction value and a wide pseudo-range correction value of each positioning satellite according to the navigation satellite signal and the wide area augmentation system signal;

the satellite navigation monitoring device respectively acquires an estimated wide area correction error value of each positioning satellite according to the local pseudo-range correction value and the wide area pseudo-range correction value of each positioning satellite;

the satellite navigation monitoring device carries the estimated wide area correction error value of each positioning satellite in local navigation parameters and broadcasts the local navigation parameters to an airborne user device, so that the airborne user device can judge the availability of the satellite navigation device according to the received local navigation parameters.

2. The method for monitoring the satellite navigation based on the LAAS and the WAAS according to claim 1, wherein the satellite navigation monitoring device obtains the local pseudorange correction value and the wide pseudorange correction value of each positioning satellite according to the navigation satellite signal and the wide area augmentation system signal, respectively, and comprises:

separately acquiring the distances between the receiver and the corresponding positioning satellites

Respectively obtaining local pseudo-range observed values and local carrier observed values of the positioning satellites according to the navigation satellite signals; and applying the formulaObtaining smoothed local pseudo-range observations of each of the positioning satellites respectively

Wherein k represents an epoch;

N_srepresenting the number of sampling points; tau is_sRepresenting the filter time constant, T_sA measurement interval representing a local pseudorange observation;

representing a local pseudorange observation,representing local carrier observations;

m represents the number of receivers, i is more than or equal to 1 and less than or equal to M;

n represents the number of positioning satellites, j is more than or equal to 1 and less than or equal to N;

according to the distanceSmoothed local pseudorange observations corresponding to the positioning satellites

Using formulas

Respectively obtaining the local pseudo range correction value of each positioning satellite

Respectively acquiring wide-area pseudo range correction values of the positioning satellites according to wide-area long-term clock correction values, wide-area troposphere correction values, wide-area ionosphere correction values and wide-area fast error correction values acquired from the wide-area augmentation system signals

3. The method as claimed in claim 2, wherein the step of obtaining the estimated wide-area correction error value of each positioning satellite by the satellite navigation monitoring device according to the local pseudorange correction value and the wide-area pseudorange correction value of each positioning satellite comprises:

according to the local pseudo range correction value of the positioning satelliteAnd wide-area pseudorange corrections

Using formulas

Obtaining estimated wide area correction error values of each positioning satellite respectively

Wherein M represents the number of receivers, i is more than or equal to 1 and less than or equal to M;

n represents the number of positioning satellites, and j is more than or equal to 1 and less than or equal to N.

4. The LAAS and WAAS-based satellite navigation monitoring method of claim 3, wherein the determining the availability of the satellite navigation device by the onboard user device based on the received local navigation parameters comprises:

acquiring a ground monitoring protection level according to the local navigation parameters;

and comparing the ground monitoring protection level with a preset alarm threshold to obtain a comparison result, and judging the usability of the satellite navigation device according to the comparison result.

5. The LAAS and WAAS-based satellite navigation monitoring method according to claim 4, wherein the obtaining of the ground monitoring protection level according to the local navigation parameters comprises:

according to the local navigation parameters and by adopting a formula

And

respectively obtaining the vertical protection level VPL of the satellite navigation device_WLSAnd a lateral protection level LPL of a satellite navigation device_WLS；

According to the local navigation parameters and by adopting a formula

Obtaining a vertical ephemeris protection level VEB for each of the positioning satellites_jAnd a level of side ephemeris protection LEB for each of said positioning satellites_j(ii) a Respectively taking the maximum value in the vertical ephemeris protection level of the selected positioning satellite and the maximum value of the lateral ephemeris protection level of the selected positioning satellite as a vertical ephemeris protection level VEB of the navigation satellite enhancement system and a lateral ephemeris protection level LEB of the navigation satellite enhancement system;

according to the vertical protection level VPL of the satellite navigation device_WLSSide protection level LPL of satellite navigation device_WLSA vertical ephemeris protection stage VEB of the navigation satellite augmentation system and a lateral ephemeris protection stage LEB of the navigation satellite augmentation system, and the formula VPL is max (VPL)_WLSVEB) and LPL ═ max (LPL)_WLSLEB) for obtaining a vertical ground monitoring protection level VPL and a lateral ground monitoring protection level LPL;

wherein K is an error amplification factor;

m represents the number of receivers, i is more than or equal to 1 and less than or equal to M;

n represents the number of positioning satellites, j is more than or equal to 1 and less than or equal to N;

S_v(j) representing a transformation matrix from the pseudo-local area to the localization domain;

S_L(j)＝S_y(j) wherein S is_y(j) Represents the j column element related to the y direction in the S matrix;

S_z(j)、S_x(j) and S_y(j) Respectively representing j-th column elements related to the z direction, the x direction and the y direction in the S matrix;

σ_tot(j) total standard deviation calculated for user for j positioning satellite；

Averaging the estimated wide-area correction error values for the M receivers;

χ_airis the distance between the airborne user device and the ground reference station, in meters;

P_jephemeris related parameters;

K_{md_e}and the missed detection probability coefficient corresponds to the integrity risk value when a single positioning satellite fails.

6. A satellite navigation monitoring system based on LAAS and WAAS is characterized by comprising a LAAS receiver, a WAAS receiver, a satellite navigation monitoring device and an airborne user device, wherein,

the LAAS receiver is used for receiving navigation satellite signals, and the WAAS receiver is used for receiving wide area augmentation system signals;

the satellite navigation monitoring device comprises:

the signal acquisition module is used for respectively acquiring the navigation satellite signals and the wide area augmentation system signals received by each receiver;

the correction value acquisition module is used for respectively acquiring the local pseudo-range correction value and the wide-area pseudo-range correction value of each positioning satellite according to the navigation satellite signals and the wide-area augmentation system signals;

the estimated correction error value acquisition module is used for respectively acquiring estimated wide area correction error values of the positioning satellites according to the local pseudo-range correction values and the wide pseudo-range correction values of the positioning satellites;

and the sending module is used for carrying the estimated wide area correction error value of each positioning satellite in local navigation parameters and broadcasting the local navigation parameters to the airborne user device so that the airborne user device can judge the availability of the satellite navigation device according to the received local navigation parameters.

7. The LAAS and WAAS-based satellite navigation monitoring system of claim 6, wherein the correction value obtaining module comprises:

a distance acquisition unit for respectively acquiring the distances of the positioning satellites corresponding to the receivers

The smoothing processing unit is used for respectively acquiring local pseudo-range observation values and local carrier observation values corresponding to the positioning satellites according to the navigation satellite signals; and applying the formulaObtaining smoothed local pseudo-range observations of each of the positioning satellites respectively

Wherein k represents an epoch;

N_srepresenting the number of sampling points; tau is_sRepresenting the filter time constant, T_sA measurement interval representing a local pseudorange observation;

representing a local pseudorange observation,representing local carrier observations;

m represents the number of receivers, i is more than or equal to 1 and less than or equal to M;

n represents the number of positioning satellites, j is more than or equal to 1 and less than or equal to N;

a local pseudo-range correction value acquisition unit for acquiring the local pseudo-range correction value according to the distance

Smoothed local pseudorange observations corresponding to the positioning satellitesUsing formulas

Respectively obtaining the local pseudo range correction value of each positioning satellite

A wide-area pseudo-range correction value acquisition unit, configured to acquire the wide-area pseudo-range correction values of the positioning satellites respectively according to the wide-area long-term clock correction value, the wide-area troposphere correction value, the wide-area ionosphere correction value, and the wide-area fast error correction value acquired from the wide-area augmentation system signal

8. The LAAS and WAAS based satellite navigation monitoring system of claim 7, wherein the estimator correction error value obtaining module is configured to obtain local pseudorange correction values for each positioning satellite

And wide-area pseudorange corrections

Using formulas

Obtaining estimated wide area correction error values of each positioning satellite respectively

Wherein M represents the number of receivers, i is more than or equal to 1 and less than or equal to M;

n represents the number of positioning satellites, and j is more than or equal to 1 and less than or equal to N.

9. The LAAS and WAAS based satellite navigation monitoring system of claim 8, wherein the onboard user device comprises:

the ground monitoring protection level acquisition module is used for acquiring a ground monitoring protection level according to the local navigation parameter;

and the comparison module is used for comparing the ground monitoring protection level with a preset alarm threshold to obtain a comparison result and judging the usability of the satellite navigation device according to the comparison result.

10. The LAAS and WAAS-based satellite navigation monitoring system of claim 9, wherein the ground monitoring protection level acquisition module comprises:

a satellite navigation device protection level obtaining unit for obtaining the local navigation parameters according to the formula

Andrespectively obtaining the vertical protection level VPL of the satellite navigation device_WLSAnd a lateral protection level LPL of a satellite navigation device_WLS；

A satellite navigation device ephemeris protection level acquisition unit for obtaining the local navigation parameters according to the formula

Obtaining a vertical ephemeris protection level VEB for each of the positioning satellites_jAnd a level of side ephemeris protection LEB for each of said positioning satellites_j(ii) a And the vertical ephemeris protection of the selected positioning satelliteThe maximum value in the levels and the maximum value of the lateral ephemeris protection level of the positioning satellite are respectively used as a vertical ephemeris protection level VEB of the navigation satellite enhancement system and a lateral ephemeris protection level LEB of the navigation satellite enhancement system;

a ground monitoring protection level obtaining unit for obtaining the vertical protection level VPL of the satellite navigation device_WLSSide protection level LPL of satellite navigation device_WLSA vertical ephemeris protection stage VEB of the navigation satellite augmentation system and a lateral ephemeris protection stage LEB of the navigation satellite augmentation system, and the formula VPL is max (VPL)_WLSVEB) and LPL ═ max (LPL)_WLSLEB) for obtaining a vertical ground monitoring protection level VPL and a lateral ground monitoring protection level LPL;

wherein K is an error amplification factor;

m represents the number of receivers, i is more than or equal to 1 and less than or equal to M;

n represents the number of positioning satellites, j is more than or equal to 1 and less than or equal to N;

S_v(j) representing a transformation matrix from the pseudo-local area to the localization domain;

S_L(j)＝S_y(j) wherein S is_y(j) Represents the j column element related to the y direction in the S matrix;

S_z(j)、S_x(j) and S_y(j) Respectively representing j-th column elements related to the z direction, the x direction and the y direction in the S matrix;

σ_tot(j) a total standard deviation calculated for the user for the jth positioning satellite;

an average of the estimated wide-area correction error values for the M receivers;

χ_airis the distance between the airborne user device and the ground reference station, in meters;

P_jephemeris related parameters;

K_{md_e}and the missed detection probability coefficient corresponds to the integrity risk value when a single positioning satellite fails.

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