CN-122017896-A - GNSS receiver end inter-frequency code deviation estimation method

CN122017896ACN 122017896 ACN122017896 ACN 122017896ACN-122017896-A

Abstract

The invention provides a GNSS receiver end inter-frequency code deviation estimation method, which relates to the technical field of satellite time service and comprises the steps of obtaining reference aerial signals and aerial signals to be detected which are correspondingly received by a reference GNSS receiver and a GNSS receiver to be detected, carrying out smoothing processing on the corresponding reference aerial signals and aerial signals to be detected by a current frequency point pair to correspondingly obtain reference pseudo-range information and pseudo-range information to be detected, respectively carrying out inter-frequency difference processing on the reference pseudo-range information and the pseudo-range information to be detected to correspondingly obtain a reference inter-frequency difference result and an inter-frequency difference result to be detected, carrying out inter-station difference processing on the reference inter-frequency difference result and the inter-frequency difference result to be detected according to corresponding satellites at the same moment to obtain inter-frequency code deviation estimation values corresponding to the current frequency point pair, and carrying out the operation on all the current frequency point pairs to obtain the inter-frequency code deviation estimation values corresponding to each current frequency point pair of the GNSS receiver to be detected. Thus, the practicability and reliability of the method are improved.

Inventors

XU LONGXIA
ZHU FENG
LIU YA
LI XIAOHUI

Assignees

中国科学院国家授时中心

Dates

Publication Date: 20260512
Application Date: 20260313

Claims (8)

1. The method for estimating the inter-frequency code bias of the GNSS receiver end is characterized by comprising the following steps: s101, acquiring air signals of a reference GNSS receiver and a GNSS receiver to be detected which are connected under the same antenna set in a static operation mode, and correspondingly acquiring the reference air signals and the air signals to be detected; S102, selecting any frequency point as a reference frequency point, taking all frequency points except the reference frequency point as other frequency points, sequentially selecting a current frequency point from the other frequency points, and forming a current frequency point pair with the reference frequency point; S103, carrying out smoothing processing on the reference aerial signal and the aerial signal to be detected corresponding to the current frequency point to correspondingly obtain reference pseudo-range information and pseudo-range information to be detected; S104, respectively carrying out inter-frequency difference processing on the reference pseudo-range information and the pseudo-range information to be detected, and correspondingly obtaining a reference inter-frequency difference result and an inter-frequency difference result to be detected; s105, under the same moment, carrying out inter-station differential processing according to corresponding satellites based on the reference inter-frequency differential result and the inter-frequency differential result to be detected to obtain an inter-frequency code deviation estimated value corresponding to the current frequency point pair; s106, executing S103-S105 on all the current frequency point pairs respectively to obtain the inter-frequency code deviation estimated value corresponding to each current frequency point pair of the GNSS receiver to be detected.
2. The method for estimating an inter-frequency code bias of a GNSS receiver according to claim 1, it is characterized in that the method comprises the steps of, The reference aerial signal is formed based on the first carrier phase observation information and the first pseudo code observation information, and the aerial signal to be detected is formed based on the second carrier phase observation information and the second pseudo code observation information.
3. The method for estimating an inter-frequency code bias of a GNSS receiver according to claim 2, wherein S103 includes: Performing smoothing processing on the first pseudo code observation information by adopting a Hatch filtering method based on a preset smoothing window and the first carrier phase observation information under the current frequency point pair to obtain the reference pseudo range information; based on a preset smoothing window and the second carrier phase observation information, carrying out smoothing processing on the second pseudo code observation information by adopting a Hatch filtering method to obtain pseudo range information to be detected; wherein the preset smoothing window is greater than or equal to 60S.
4. The GNSS receiver-side inter-frequency code bias estimation method according to claim 1, wherein the reference pseudo-range information is expressed as: ; ; The pseudo-range information to be measured is expressed as: ; ; Wherein, the Reference pseudorange information representing a first frequency point of a current frequency point pair corresponding to a reference GNSS receiver, Reference pseudorange information representing a second frequency point in a current frequency point pair corresponding to the reference GNSS receiver, The pseudo-range information to be measured of the first frequency point in the current frequency point pair corresponding to the GNSS receiver to be measured is represented, The pseudo-range information to be measured of the second frequency point in the current frequency point pair corresponding to the GNSS receiver to be measured is represented, Representing reference GNSS receivers and satellites The geometric distance between the two parts of the frame, Representing GNSS receiver and satellite to be measured The geometric distance between the two parts of the frame, The speed of light is indicated as being the speed of light, Representing the clock difference of the reference GNSS receiver, Representing the clock error of the GNSS receiver to be measured, Representing satellites Is used for the time-lapse of (1), Represents tropospheric delay times of a reference GNSS receiver, Represents tropospheric delay of the GNSS receiver to be measured, Representing the additional ionospheric delay of the reference GNSS receiver at the first frequency bin of the current frequency bin pair, Representing the additional ionospheric delay of the reference GNSS receiver at the second frequency point of the current frequency point pair, Representing the additional ionospheric delay of the GNSS receiver to be measured at the first frequency point of the current frequency point pair, Representing the additional ionospheric delay of the GNSS receiver to be measured at the second frequency point of the current frequency point pair, Representing the hardware delay of the reference GNSS receiver at the first frequency point of the current frequency point pair, Representing the hardware delay of the reference GNSS receiver at the second frequency point of the current frequency point pair, Representing the hardware time delay of the GNSS receiver to be measured at the first frequency point of the current frequency point pair, Representing the hardware time delay of the GNSS receiver to be measured at the second frequency point of the current frequency point pair, Representing satellites The hardware delay at the first frequency bin of the current frequency bin pair, Representing satellites The hardware delay at the second frequency point of the current frequency point pair, Representing pseudocode observation noise of a reference GNSS receiver, And representing the pseudo code observation noise of the GNSS receiver to be detected.
5. The method of estimating an inter-frequency code bias of a GNSS receiver according to claim 4, wherein, The reference inter-frequency differential result is expressed as: ; the difference result between the frequencies to be measured is expressed as: ; a value representing the result of the difference between the reference frequencies, And a value representing the differential result between the frequencies to be measured.
6. The method for estimating an inter-frequency code bias of a GNSS receiver according to claim 1, wherein S105 includes: Based on the reference inter-frequency difference result and the inter-frequency difference result to be measured, performing inter-station difference processing according to the corresponding satellites at the same time to obtain a first inter-frequency code initial deviation estimated value corresponding to each satellite in the current frequency point pair; carrying out mean value processing on the first frequency-to-frequency code initial deviation estimated values corresponding to all satellites at the same moment to obtain a second frequency-to-frequency code initial deviation estimated value; And carrying out average value processing on the initial deviation estimated values of the second inter-frequency codes corresponding to all the same time to obtain the inter-frequency code deviation estimated value corresponding to the current frequency point pair.
7. The method for estimating an inter-frequency code bias of a GNSS receiver according to claim 6, wherein the initial bias estimation value of the first inter-frequency code is expressed as: ; Wherein, the Representing the GNSS receiver to be measured under the current frequency point pair for satellites The corresponding first inter-frequency code initial bias estimate, Representing the inter-frequency code bias value of the reference GNSS receiver at the current frequency point pair, Reference pseudorange information representing a first frequency point of a current frequency point pair corresponding to a reference GNSS receiver, Reference pseudorange information representing a second frequency point in a current frequency point pair corresponding to the reference GNSS receiver, The pseudo-range information to be measured of the first frequency point in the current frequency point pair corresponding to the GNSS receiver to be measured is represented, And the pseudo-range information to be measured of the second frequency point in the current frequency point pair corresponding to the GNSS receiver to be measured is represented.
8. The method for estimating the inter-frequency code bias of the GNSS receiver according to claim 1, wherein the sampling frequency in the static operation mode is 1Hz or less, and the observation elevation angle is 30 ° or more.

Description

GNSS receiver end inter-frequency code deviation estimation method Technical Field The invention relates to the technical field of satellite time service, in particular to a GNSS (Global Navigation SATELLITE SYSTEM ) receiver end frequency code deviation estimation method. Background The satellite navigation system broadcasts service signals through different frequency points, and provides a foundation for various applications. The receiver is a necessary terminal for users to use the service, and when signals pass through the internal hardware link of the receiver, different frequency points can generate different delays, and the difference value is the inter-frequency code deviation of the receiver. This bias has time-varying properties and is one of the key sources of error that must be handled when using ionospheric-free dual-frequency combined observations to eliminate the effects of ionospheric delay. For applications based on dual-frequency combined observations, such as high-precision timing, time transfer, etc., the receiver-side inter-frequency code bias is an important factor affecting the accuracy of the result, and therefore, accurate determination of the bias has clear technical necessity. Currently, there are three main prior art methods of determining this deviation. One method is based on external ionosphere products, namely, products such as global ionosphere grid images are utilized, the total electronic content of an ionosphere is regarded as a known quantity, and differential code deviation is directly calculated. And secondly, constructing an ionosphere model by using ground multi-station observation data, and estimating the receiver end inter-frequency code deviation as an unknown parameter together with the ionosphere model parameter. And thirdly, direct measurement, namely special equipment such as GNSS signal simulation sources, oscilloscopes and the like, directly calibrating absolute delay values of the receiver at all frequency points, and further calculating and obtaining code deviation among the frequency points. However, the above prior art methods all have respective limitations. According to the method based on the external product, the ionosphere observation value on which the calculation depends is easily influenced by multipath effect and pseudo-range noise, and the final precision is limited by the satellite end inter-frequency deviation and the precision of the adopted ionosphere product, so that the real-time performance and the precision are both insufficient. The joint estimation method needs to rely on multi-station networking observation, a single receiver cannot be independently implemented, parameters to be estimated are numerous, and implementation difficulty is high. The direct measurement method needs to rely on expensive professional instruments and specific calibration environments, and the calibration process is complex, complicated in steps and long in time consumption. Disclosure of Invention In order to solve the above problems in the prior art, the present invention provides a method for estimating inter-frequency code bias of a GNSS receiver. The technical problems to be solved by the invention are realized by the following technical scheme: The invention provides a GNSS receiver end frequency code deviation estimation method, which comprises the following steps: s101, acquiring air signals of a reference GNSS receiver and a GNSS receiver to be detected which are connected under the same antenna set in a static operation mode, and correspondingly acquiring the reference air signals and the air signals to be detected; S102, selecting any frequency point as a reference frequency point, taking all frequency points except the reference frequency point as other frequency points, sequentially selecting a current frequency point from the other frequency points, and forming a current frequency point pair with the reference frequency point; S103, carrying out smoothing processing on the corresponding reference aerial signal and the aerial signal to be detected of the current frequency point, and correspondingly obtaining reference pseudo-range information and pseudo-range information to be detected; S104, carrying out inter-frequency difference processing on the reference pseudo-range information and the pseudo-range information to be detected respectively to correspondingly obtain a reference inter-frequency difference result and an inter-frequency difference result to be detected; s105, under the same moment, carrying out inter-station differential processing according to the corresponding satellite based on the reference inter-frequency differential result and the inter-frequency differential result to be detected to obtain an inter-frequency code deviation estimated value corresponding to the current frequency point pair; s106, executing S103-S105 on all the current frequency point pairs respectively to obtain the inter-frequency code deviation estimated v