Error correction method for foundation multi-station distance measurement orbit determination system

Abstract

The invention discloses an error correction method for a foundation multi-station distance measurement and orbit determination system, and relates to the field of foundation multi-station distance measurement and orbit determination. The method comprises the following steps: firstly, analyzing off-line data to obtain a distance measurement residual error result of an orbit determination result; solving the distance measurement system difference of the ground station to be corrected in the orbit determination process by using multi-station stable measurement data based on an EMBET algorithm; secondly, reversely deducing offset zero value correction according to the calculated distance measurement system difference, and calculating new offset zero values of the L and S frequency bands; and finally, generating a new observation file, carrying out orbit determination solution, analyzing a distance measurement residual error result correction condition, and continuously correcting until no ground station to be corrected exists. The method not only can reproduce the orbit determination result of the system, but also can perform off-line orbit determination after correcting the measured data as required, and has the characteristics of simplicity and convenience in operation and flexibility in use. Besides, on the basis of stable operation of the ground station, system differences of other stations are solved, the process of equipment calibration is omitted, and manpower and material resource costs are saved.

Description

Technical Field

[0001] The invention relates to the field of ground-based multi-station ranging and orbit determination, and in particular to an error correction method for a ground-based multi-station ranging and orbit determination system. Background Art

[0002] GEO satellites are characterized by high orbits, geostationary locations, and frequent orbital maneuvers. In a ground-based multi-station ranging and orbit determination system, tiny errors introduced during the measurement process will be magnified by 20 times to the satellite's orbit determination position accuracy, which is unacceptable for an orbit determination accuracy of the order of ten meters.

[0003] In previous projects, in order to ensure measurement accuracy, it is necessary to regularly calibrate the measuring equipment to zero value. However, on the one hand, due to the wide distribution of ground stations and the complex calibration process, special personnel need to be assigned for regular maintenance, resulting in a large amount of manpower and material resources consumption; on the other hand, the ground-based ranging and orbit determination system is a high-precision measurement system, and even a small measurement error will cause the orbit determination accuracy to fail to meet the standard. Therefore, the measuring equipment (antenna, channel, baseband, bias feed and other subsystems) needs to operate stably. However, in actual work, it is often encountered that the equipment status has a small fluctuation or the tree is blocked, which causes the equipment zero value calibration to be inaccurate, resulting in a decrease in orbit determination accuracy. Summary of the invention

[0004] In view of this, the present invention proposes an error correction method for a ground-based multi-station ranging and orbit determination system. This method can not only reproduce the system orbit determination results, but also correct the measurement data as needed before offline orbit determination, and has the characteristics of simple operation and flexible use. In addition, on the basis of stable operation of the ground station, the system difference of other stations is solved, which saves the equipment calibration process and saves manpower and material costs.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is as follows:

[0006] An error correction method for a ground-based multi-station ranging and orbit determination system comprises the following steps:

[0007] Step 1: Get the offline orbit determination result data folder, check the orbit determination accuracy, and graphically display the orbit determination residual file, obtain the ranging residual graph of this orbit determination result and set the normal range of ranging residual;

[0008] Step 2: The ground stations whose ranging residual results are within the normal range of ranging residuals are recorded as normal ground stations, and the ground stations whose ranging residual results are beyond the normal range of ranging residuals are recorded as ground stations to be corrected;

[0009] Step 3: Use the stable measurement data of at least three normal ground stations and the EMBET self-calibration algorithm to solve the ranging system error of one of the ground stations to be corrected, and obtain the L-band ranging compensation value ΔL of the current ground station to be corrected. obs And S-band ranging compensation value ΔS obs ;

[0010] Step 4: Calculate the L-band offset zero correction Δρ for the current ground station to be corrected. 偏馈零值L :

[0011]

[0012] Calculate the S-band bias feed zero correction Δρ 偏馈零值S :

[0013]

[0014] Where M = (L b -S b )-(ρ 设备零值L -ρ 设备零值S ), L b With S b are the offset feedback ranging results of the L-band and S-band zeroing corresponding to the current ground station to be corrected in the offset feedback zeroing loop; ρ 设备零值L and ρ 设备零值S are the one-way equipment zero values ​​of the L-band and S-band corresponding to the current ground station to be corrected; f L With f S are respectively the carrier frequencies of the L-band and S-band corresponding to the current ground station to be corrected;

[0015] Step 5: For the current ground station to be corrected, calculate the corrected offset zero values ​​of its L-band and S-band respectively:

[0016] ρ 偏馈零值L_new =ρ 偏馈零值L +Δρ 偏馈零值L ;

[0017] ρ 偏馈零值S_new =ρ 偏馈零值S +Δρ 偏馈零值S ;

[0018] Among them, ρ 偏馈零值L and ρ 偏馈零值S are the initial bias zero values ​​of the L-band and S-band corresponding to the current ground station to be corrected, ρ 偏馈零值L_new and ρ 偏馈零值S_new They are respectively the corrected bias feed zero values ​​of the L-band and S-band corresponding to the current ground station to be corrected;

[0019] Step 6: Calculate the single-station ranging value L after L-band correction for the current ground station to be corrected. obs_New :

[0020] L obs_New =L obs -ρ 偏馈零值L_new +ρ 设备零值L ;

[0021] Calculate the single-station ranging value S after the S-band correction obs_New :

[0022] S obs_New =S obs -ρ 偏馈零值S_new +ρ 设备零值S ;

[0023] Among them, L obs With S obs They are respectively the initial single-station ranging values ​​of the L-band and S-band corresponding to the current ground station to be corrected;

[0024] Step 7: Calculate the corrected ionospheric delay value ρ for the current ground station to be corrected 电离层_New :

[0025]

[0026] Step 8: According to L obs_New , S obs_New and ρ 电离层_New The value of generates the observation data file and performs the orbit determination calculation function to obtain the updated ranging residual map;

[0027] Step 9, repeat steps 2 to 8 until the ranging residual results of all ground stations are within the normal range of ranging residuals, completing the error correction for the ground-based multi-station ranging and orbit determination system.

[0028] Due to the adoption of the above technical solution, the beneficial effects of the present invention compared with the prior art are:

[0029] 1. Starting from the perspective of orbit determination error sources, the present invention uses the EMBET self-calibration technology to conduct a comprehensive and systematic analysis of offline orbit determination data, and has the characteristics of simple operation and flexible use.

[0030] 2. The present invention solves the system difference of other stations on the basis of stable operation of the ground station, thus saving the equipment calibration process and saving manpower and material costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 The present invention is an overall flow chart of an error correction method for a ground-based multi-station ranging and orbit determination system in an embodiment of the present invention.

[0032] Figure 2 Schematic diagram of ranging residual in an embodiment of the present invention. DETAILED DESCRIPTION

[0033] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

[0034] An error correction method for ground-based multi-station ranging and orbit determination system, such as Figure 1 As shown, the following steps are included;

[0035] 1) Obtain the offline orbit determination result data folder, check the orbit determination accuracy, and graphically display the orbit determination residual files, such as Figure 2 As shown in the figure, draw the ranging residual diagram of this orbit determination, and preliminarily find the stations with large system errors and record them as ground stations to be corrected;

[0036] 2) Calculate the distance measurement system error

[0037] Based on the EMBET self-calibration algorithm, the stable measurement data of at least three stations are used to solve the ranging system error of one of the ground stations to be corrected, and its ranging compensation value ΔL is obtained. obs and ΔS obs .

[0038] 3) Calculate the bias feed zero correction value of the ground station to be corrected

[0039] Step 1: Task loop, the L-band single-station ranging value is expressed by the following formula:

[0040] L obs =ρ 真 -ρ 设备零值L -ρ 星上零值 (1)

[0041] Among them, L obs is the L-band single-station ranging value (without deducting the ionospheric delay value), ρ 真 is the true distance of the star station, ρ 设备零值L is the zero value of a one-way L-band device, ρ 星上零值 It is zero value on a one-way satellite.

[0042] Step 2: Offset feed zero calibration loop, offset feed ranging results for L-band zero calibration:

[0043] L b =ρ 偏馈零值L +ρ 设备零值L (2)

[0044] L b It is the ranging result of the L offset feedback loop during zero calibration. Therefore, when the mission is running normally, this value is a fixed constant.

[0045] Step 3: Task loop, the S-band single-station ranging value is expressed by the following formula:

[0046] S obs =ρ 真 -ρ 设备零值S -ρ 星上零值 (3)

[0047] Among them, S obs is the S-band single-station ranging value (without deducting the ionospheric delay value), ρ 真 is the true distance of the star station, ρ 设备零值S is the zero value of a one-way S-band device, ρ 星上零值 It is zero value on a one-way satellite.

[0048] Step 4: Offset feed zero calibration loop, offset feed ranging results for S-band zero calibration:

[0049] S b =ρ 偏馈零值S +ρ 设备零值S (4)

[0050] S b It is the ranging result of the S bias feedback loop during zero calibration. Therefore, when the mission is running normally, this value is a fixed constant.

[0051] Step 5: The ionospheric delay adopts the dual-frequency ionospheric correction model. After the relevant parameters are converted, the ionospheric delay value can be expressed by the following formula:

[0052]

[0053] Among them, f L 、f S is the carrier frequency.

[0054] Step 6: Substituting (1) to (4) into (5), we can obtain:

[0055]

[0056] Step 7: If the L-band ranging value offset zero value needs to be corrected Δρ 偏馈零值L , the S-band ranging value bias feed zero value needs to be corrected Δρ 偏馈零值S , from formula (6) we can get:

[0057] Ionospheric delay correction: L observation value correction: S observation value correction:

[0058] Step 8: According to the device status requirements, there are the following constraints

[0059] 3.5≤ρ 偏馈零值L -ρ 偏馈零值S ≤6(10)

[0060] Step 9: L-band ranging bias feed zero value is Δρ 偏馈零值L Change, the S-band ranging bias feed zero value is Δρ 偏馈零值S Change, then equation (2) and equation (4) become the following formula:

[0061] L bNew =ρ 偏馈零值L +Δρ 偏馈零值L +ρ 设备零值L (11)

[0062] S bNew =ρ 偏馈零值S +Δρ 偏馈零值S +ρ 设备零值S (12)

[0063] Substituting equations (11) and (12) into equation (10), we can obtain:

[0064] M-6≤Δρ 偏馈零值L -Δρ 偏馈零值S ≤M-3.5(13)

[0065] Where M = (L bNew -S bNew )-(ρ 设备零值L -ρ 设备零值S ), due to L bNew , S bNew The equipment needs to be recalibrated, which is expensive and inconsistent with the original intention of this embodiment. 偏馈零值L , Δρ 偏馈零值S Relative to L b , S b Therefore, L is used to calculate M. b , S b are approximately equal to L bNew , S bNew , that is, M=(L b -S b )-(ρ 设备零值L -ρ 设备零值S );

[0066] Step 10: Calculate the L-band offset zero correction Δρ 偏馈零值L

[0067] Combining equation (9) and equation (13), we can get:

[0068]

[0069] Select the appropriate L-band offset zero correction value according to the device status.

[0070] Step 11: Calculate the S-band offset zero correction Δρ 偏馈零值S

[0071] Combining equation (8) and equation (13), we can get:

[0072]

[0073] Select the appropriate S-band offset zero correction value according to the device status.

[0074] 4) Calculate the new L and S bias feed zero values

[0075] ρ 偏馈零值L_new =ρ 偏馈零值L +Δρ 偏馈零值L (16)

[0076] ρ 偏馈零值S_new =ρ 偏馈零值S +Δρ 偏馈零值S (17)

[0077] 5) Regenerate observation data file

[0078] Substitute the results of equations (16) and (17) into equations (2) and (4) to calculate the new device zero value. According to equation (1):

[0079] L obs =ρ 真 -ρ 设备零值L -ρ 星上零值 (18)

[0080] L obs_New =ρ 真 -ρ 偏馈零值L_new -ρ 星上零值 (19)

[0081] The corrected L-band ranging value can be obtained from equations (18) and (19):

[0082] L obs_New =L obs -ρ 偏馈零值L_new +ρ 设备零值L (20)

[0083] Similarly, the corrected S-band ranging value can be obtained:

[0084] S obs_New =S obs -ρ 偏馈零值S_new +ρ 设备零值S (twenty one)

[0085] Substituting the results of equations (20) and (21) into equation (5) yields the corrected ionospheric delay value:

[0086]

[0087] The corrected L-band ranging value and ionospheric delay value calculated by equations (20) and (22) are used to generate observation data files in a predetermined format.

[0088] 6) Perform orbit determination calculations, analyze ranging residual diagrams, and observe improvements in measurement system errors.

[0089] Repeat steps 2) to 6) until the ranging residual results of all ground stations are within the normal range of ranging residuals, completing the error correction for the ground-based multi-station ranging and orbit determination system.

[0090] In short, the present invention can not only reproduce the system orbit determination results, but also correct the measured data as needed and then perform offline orbit determination, which is easy to operate and flexible to use. In addition, on the basis of stable operation of the ground station, the system difference of other stations is solved, which saves the equipment calibration process and saves manpower and material costs.

[0091] Those skilled in the art will appreciate that the embodiments described are intended to help readers understand the principles of the present invention, and should be understood that the scope of protection of the present invention is not limited to the embodiments described. For those skilled in the art, the present invention may have various changes and variations. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of the claims of the present invention.

Claims

1. An error correction method for a ground-based multi-station ranging and orbit determination system, characterized in that: The steps include: Step 1: Get the offline orbit determination result data folder, check the orbit determination accuracy, and graphically display the orbit determination residual file, obtain the ranging residual graph of this orbit determination result and set the normal range of ranging residual; Step 2: The ground stations whose ranging residual results are within the normal range of ranging residuals are recorded as normal ground stations, and the ground stations whose ranging residual results are beyond the normal range of ranging residuals are recorded as ground stations to be corrected; Step 3: Use the stable measurement data of at least three normal ground stations and the EMBET self-calibration algorithm to solve the ranging system error of one of the ground stations to be corrected, and obtain the L-band ranging compensation value ΔL of the current ground station to be corrected. obs And S-band ranging compensation value ΔS obs ; Step 4: Calculate the L-band bias feed zero correction Δρ for the current ground station to be corrected. 偏馈零值L : Calculate the S-band bias feed zero correction Δρ 偏馈零值S : Where M = (L b -S b )-(ρ 设备零值L -ρ 设备零值S ), L b With S b are the offset feedback ranging results of the L-band and S-band zeroing corresponding to the current ground station to be corrected in the offset feedback zeroing loop; ρ 设备零值L and ρ 设备零值S are the one-way equipment zero values ​​of the L-band and S-band corresponding to the current ground station to be corrected; f L With f S are respectively the carrier frequencies of the L-band and S-band corresponding to the current ground station to be corrected; Step 5: For the current ground station to be corrected, calculate the corrected offset zero values ​​of its L-band and S-band respectively: r 偏馈零值L_new =ρ 偏馈零值L +Dr 偏馈零值L ; r 偏馈零值S_new =ρ 偏馈零值S +Dr 偏馈零值S ; Among them, ρ 偏馈零值L and ρ 偏馈零值S are the initial bias zero values ​​of the L-band and S-band corresponding to the current ground station to be corrected, ρ 偏馈零值L_new and ρ 偏馈零值S_new They are respectively the corrected bias feed zero values ​​of the L-band and S-band corresponding to the current ground station to be corrected; Step 6: Calculate the single-station ranging value L after L-band correction for the current ground station to be corrected. obs_New : L obs_New =L obs -r 偏馈零值L_new +r 设备零值L ; Calculate the single-station ranging value S after the S-band correction obs_New : S obs_New =S obs -r 偏馈零值S_new +r 设备零值S ; Among them, L obs With S obs They are respectively the initial single-station ranging values ​​of the L-band and S-band corresponding to the current ground station to be corrected; Step 7: Calculate the corrected ionospheric delay value ρ for the current ground station to be corrected 电离层_New : Step 8: According to L obs_New , S obs_New and ρ 电离层_New The value of generates the observation data file and performs the orbit determination calculation function to obtain the updated ranging residual map; Step 9, repeat steps 2 to 8 until the ranging residual results of all ground stations are within the normal range of ranging residuals, completing the error correction for the ground-based multi-station ranging and orbit determination system.

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