A method for processing GBAS B-value supporting multiple monitoring stations

Abstract

The application designs a GBAS B value processing method supporting multiple monitoring stations, and belongs to the integrity monitoring field of satellite navigation. The method is based on multiple ground stations, and a GBAS B value processing method is constructed. The method overcomes the influence of the logical switching of the selected ground station on the center point and availability by increasing the number of ground stations, and improves the user positioning accuracy. The method has important research significance and application value for the GBAS field.

Description

TECHNICAL FIELD

[0001] The application relates to a GBAS B value processing method supporting multiple monitoring stations and belongs to the integrity monitoring field of satellite navigation. BACKGROUND

[0002] The B value is an important parameter for positioning of a ground user of a GBAS. According to the RTCA-DO246 protocol, the user uses four groups of B values for positioning. However, for user positioning, six ground stations are generally used instead of four. Therefore, four ground stations are selected from the six ground stations, and the selection needs to be completed through logic selection. At present, the method used by Honeywell is just this method. However, this method makes the user use only four ground stations for positioning, and the positioning precision is lower than that of using six ground stations for positioning. Moreover, the logic switching of selecting four ground stations from the six ground stations has certain influences on the center point and availability.

[0003] Therefore, it is of important research significance and application value to construct a GBAS B value processing method supporting multiple monitoring stations. SUMMARY

[0004] The application aims to overcome the influences of the logic switching of selecting ground stations on the center point and availability, and improve the user positioning precision, and provides a GBAS B value processing method supporting multiple monitoring stations.

[0005] The application is achieved through the following technical scheme:

[0006] A GBAS B value processing method supporting multiple monitoring stations comprises the following steps:

[0007] (101) For selection of different satellites, each ground station respectively performs differential integrity processing, and a group of B values is calculated under each satellite geometry distribution condition;

[0008] (102) The protection level results corresponding to each ground station under different satellite geometry distribution conditions are calculated through the calculated B values;

[0009] (103) The protection level results corresponding to each ground station under each satellite geometry distribution condition are sorted to obtain the maximum result under each satellite geometry distribution condition;

[0010] (104) A group of B values satisfying the following constraints is searched: the protection level calculated from the B values is greater than the maximum result obtained in step three under any condition.

[0011] The application has the following beneficial effects compared with the prior art:

[0012] This patent uses multiple monitoring stations to confirm the B value, which improves the positioning accuracy based on four monitoring stations. Attached Figure Description

[0013] Figure 1 This is a flowchart of an embodiment of the present invention. Detailed Implementation

[0014] To better illustrate the purpose and advantages of the present invention, the following description is provided in conjunction with the appendix. Figure 1 The technical solutions of the present invention will be further explained in the examples and embodiments.

[0015] Assume the GBAS system has 6 ground stations, 5 satellites in total, and 6 receivers at each ground station.

[0016] Step one: Differential integrity processing is performed at each ground station, yielding a set of B values. For different satellite selections, the geometric distribution of the satellites can be categorized as follows:

[0017]

[0018]

[0019] in Let B represent the B value corresponding to the j-th receiver of the i-th satellite in the k-th case, where k≤6, i≤5, j≤6.

[0020] Step two, the protection level can be calculated using the following formula:

[0021]

[0022] Where i represents the i-th satellite, σ i Let S represent the variance of the pseudorange measurement error of the i-th satellite, and K represent the known matrix. md The false alarm rate represents the failure rate of the ground subsystem, and N represents the number of satellites.

[0023]

[0024] Each distribution can yield a maximum of 6 protection level results. These results are denoted as:

[0025]

[0026] in, This represents the protection level result corresponding to the j-th receiver under the k-th satellite geometric distribution, where k≤6 and j≤6.

[0027] Step 3: For the 6 protection level results in each case, sort them and obtain the largest result, denoted as MAX. kMAX k The maximum protection level result under the k-th satellite geometric distribution, where k≤6.

[0028] Step 4: Find a set of B values ​​that satisfy the following constraints.

[0029] .

Claims

1. A method for processing GBAS B values ​​supporting multiple monitoring stations, characterized in that, Includes the following steps: (101) For different satellite selections, differential integrity processing is performed on each ground station under each satellite geometric distribution, and a set of B values ​​are calculated. (102) Using the calculated B value, calculate a set of protection level results for each ground station under different satellite geometric distribution conditions; (103) For each satellite geometric distribution, sort the protection level results corresponding to each ground station and obtain the maximum result for each satellite geometric distribution. (104) Find a set of B values ​​that satisfy the following constraint: In any case, the protection level calculated from the B values ​​is greater than the maximum result obtained in step three.

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