CN-121995414-A - GNSS standard single-point positioning method and system based on subcarrier observation value reconstruction

CN121995414ACN 121995414 ACN121995414 ACN 121995414ACN-121995414-A

Abstract

The invention provides a GNSS standard single-point positioning method and system based on subcarrier observation value reconstruction, which belong to the technical field of satellite navigation positioning, wherein the method comprises reconstructing subcarrier phase observation values, carrier phase observation values and pseudo-range observation values of GNSS broadband signals in an observation domain according to pseudo-range observation values and carrier phase observation values of upper and lower sideband signals of the GNSS broadband signals, and performing quality control on the reconstructed subcarrier phase observation values; and estimating floating ambiguity in the reconstructed subcarrier phase observation value, converting the reconstructed subcarrier phase observation value into absolute distance information according to the floating ambiguity, and carrying out standard single-point positioning according to the absolute distance information to output receiver position information. The invention can improve the GNSS standard single-point positioning performance under the existing main stream baseband tracking loop frame, can effectively reduce the large-scale application and popularization difficulty of the subcarrier positioning technology, and has wide application prospect.

Inventors

WANG PAI
ZHAO LONG
REN XIAODONG

Assignees

武汉大学

Dates

Publication Date: 20260508
Application Date: 20260212

Claims (10)

1. The GNSS standard single-point positioning method based on subcarrier observation value reconstruction is characterized by comprising the following steps of: Receiving GNSS broadband signal intermediate frequency data, respectively tracking an upper sideband signal and a lower sideband signal of the GNSS broadband signal, and respectively generating pseudo-range observation values and carrier phase observation values of the upper sideband signal and the lower sideband signal; Reconstructing a subcarrier phase observation value and a carrier phase observation value of the GNSS broadband signal in an observation domain according to the carrier phase observation values of the upper sideband signal and the lower sideband signal, and reconstructing a pseudo-range observation value of the GNSS broadband signal in the observation domain; performing quality control on the reconstructed subcarrier phase observations according to the reconstructed subcarrier phase observations, the reconstructed carrier phase observations and the reconstructed pseudo-range observations; and estimating floating ambiguity in the reconstructed subcarrier phase observation value according to the reconstructed pseudo-range observation value, converting the reconstructed subcarrier phase observation value into absolute distance information according to the floating ambiguity, and carrying out standard single-point positioning according to the absolute distance information to output receiver position information.
2. The method for positioning a GNSS standard single point based on subcarrier observation reconstruction according to claim 1, wherein the receiving GNSS wideband signal intermediate frequency data, tracking an upper sideband signal and a lower sideband signal of the GNSS wideband signal respectively, and generating pseudo-range observations and carrier phase observations of the upper sideband signal and the lower sideband signal respectively, further comprises: Constructing cycle slip test quantities through inter-epoch difference, and respectively detecting cycle slips in carrier phase observed values of the upper sideband signal and the lower sideband signal; For the situation of receiving a single-frequency GNSS broadband signal, calculating first-order differences among epochs of carrier phase observation values of an upper sideband signal and a lower sideband signal and second-order differences among epochs based on Doppler integration respectively, and constructing cycle slip test quantity; for the situation of receiving the multi-frequency GNSS broadband signals, calculating inter-epoch first-order difference of MW combination and inter-epoch first-order difference of GF combination respectively for the observed values of the upper sideband signals/the lower sideband signals of the two GNSS broadband signals, and constructing cycle slip test quantity; And if the cycle slip is judged to occur, performing cycle slip marking.
3. The GNSS standard single point positioning method based on subcarrier observation reconstruction as claimed in claim 1, wherein reconstructing subcarrier phase observations and carrier phase observations of the GNSS wideband signals in an observation domain from carrier phase observations of the upper and lower sideband signals includes: subtracting the carrier phase observation values of the upper sideband signal and the lower sideband signal, multiplying the carrier phase observation values by subcarrier wavelength, and obtaining a subcarrier phase observation value reconstructed by the GNSS broadband signal in an observation domain; and adding the carrier phase observed values of the upper sideband signal and the lower sideband signal, multiplying the carrier phase observed values by the wavelength of the GNSS broadband signal, and obtaining the carrier phase observed value reconstructed by the GNSS broadband signal in an observation domain.
4. The method of claim 3, wherein reconstructing the pseudorange observations of the GNSS wideband signals in the observation domain comprises: And carrying out power weighting on the pseudo-range observation values of the upper sideband signal and the lower sideband signal, and obtaining the pseudo-range observation value reconstructed by the GNSS broadband signal in an observation domain.
5. The method for GNSS standard single point positioning based on subcarrier observation reconstruction according to claim 1, wherein the quality control of the reconstructed subcarrier phase observations based on the reconstructed subcarrier phase observations, the reconstructed carrier phase observations and the reconstructed pseudo-range observations includes: Respectively calculating a first difference value of the reconstructed pseudo-range observation value and the reconstructed subcarrier phase observation value under the current epoch, and a second difference value of the reconstructed carrier phase observation value and the reconstructed subcarrier phase observation value; respectively carrying out inter-epoch difference on the first difference value and the second difference value to form two subcarrier cycle slip test amounts; And performing cycle slip detection on the reconstructed subcarrier phase observation value according to the two subcarrier cycle slip detection amounts, estimating an integer cycle slip under the condition that the occurrence of the cycle slip is judged, and performing cycle slip repair on the reconstructed subcarrier phase observation value according to the integer cycle slip.
6. The method for positioning a single point of a GNSS standard based on subcarrier observations reconstruction as claimed in claim 1, wherein, the estimating floating ambiguity in the reconstructed subcarrier phase observations according to the reconstructed pseudo-range observations comprises: Correcting satellite-end hardware deviation in the reconstructed pseudo-range observation value by using satellite-end hardware deviation correction obtained by demodulating the navigation message to obtain a reconstructed pseudo-range observation value correction value; calculating a third difference between the reconstructed pseudorange observation correction and the reconstructed subcarrier phase observation; And taking the average value of the third difference value as floating ambiguity of the reconstructed subcarrier phase observation value in a preset time window.
7. The method for GNSS standard single point positioning based on subcarrier observation reconstruction as set forth in claim 6, wherein said converting the reconstructed subcarrier phase observations into absolute distance information based on the floating ambiguity, performing standard single point positioning based on the absolute distance information, outputting receiver position information, includes: adding the floating ambiguity to the reconstructed subcarrier phase observation value to obtain absolute distance information; And correcting satellite orbit errors, satellite clock errors, ionospheric delays and tropospheric delays in the absolute distance information by combining satellite ephemeris and an atmospheric delay model, and estimating to obtain receiver position information.
8. A GNSS standard single point positioning system based on subcarrier observation reconstruction, comprising: The system comprises a sideband observation value generation module, a carrier phase observation value generation module and a carrier phase detection module, wherein the sideband observation value generation module is used for receiving GNSS broadband signal intermediate frequency data, respectively tracking an upper sideband signal and a lower sideband signal of the GNSS broadband signal, and respectively generating pseudo-range observation values and carrier phase observation values of the upper sideband signal and the lower sideband signal; a broadband observation value reconstruction module, configured to reconstruct a subcarrier phase observation value and a carrier phase observation value of the GNSS broadband signal in an observation domain according to carrier phase observation values of the upper sideband signal and the lower sideband signal, and reconstruct a pseudo-range observation value of the GNSS broadband signal in an observation domain; And the subcarrier positioning module is used for estimating floating ambiguity in the reconstructed subcarrier phase observation value according to the reconstructed pseudo-range observation value, converting the reconstructed subcarrier phase observation value into absolute distance information according to the floating ambiguity, and carrying out standard single-point positioning according to the absolute distance information to output receiver position information.
9. An electronic device comprising a memory, a processor and a computer program stored on the memory and executable on the processor, wherein the processor implements the GNSS standard single point positioning method based on subcarrier observations reconstruction as claimed in any of claims 1 to 7 when the program is executed.
10. A non-transitory computer readable storage medium having stored thereon a computer program, which when executed by a processor implements the GNSS standard single point positioning method based on subcarrier observation reconstruction according to any of claims 1 to 7.

Description

GNSS standard single-point positioning method and system based on subcarrier observation value reconstruction Technical Field The invention relates to the technical field of satellite navigation positioning, in particular to a GNSS standard single-point positioning method and system based on subcarrier observation value reconstruction. Background The global Navigation satellite system (Global Navigation SATELLITE SYSTEM, GNSS) is continuously pushing numerous industries to develop automation and intelligence as a key spatio-temporal information infrastructure with global coverage, all-day, all-weather Positioning, navigation and time service (PNT) capabilities. In the process of GNSS modernization, in order to improve the spectrum resource utilization efficiency and enhance the compatibility and interoperability between different systems, a wideband subcarrier modulation technique is widely used for new generation GNSS signals. Representative are typically MBOC signals comprising L1C/E1/B1C frequency bands, and E5 AltBOC, B2 ACE-BOC, B1 SCBOC signals formed by combining adjacent frequency bins. Such wideband subcarrier modulated signals exhibit significant high-precision ranging potential in noisy, multipath and interference environments by virtue of their large bandwidth characteristics. In order to break through the inherent limitations of the traditional pseudo code ranging signal that the noise is large and the influence of multipath is easy, development of a novel processing method capable of efficiently extracting and utilizing the high-precision subcarrier observation value of the broadband signal is needed to further improve the GNSS standard single-point positioning performance. However, as the order of the subcarriers increases, the multimodal structure of the autocorrelation function of the wideband subcarrier modulation signal becomes increasingly complex, resulting in a dramatic increase in its processing difficulty and implementation complexity. Specifically, the traditional one-dimensional tracking method for estimating the pseudo code and the subcarrier delay as common parameters faces a serious risk of locking a secondary peak, and the robust non-fuzzy tracking of the broadband subcarrier modulation signal is difficult to realize. Although the existing two-dimensional tracking method can fundamentally eliminate the problem of pseudo code tracking ambiguity and generate independent subcarrier phase observations by independently estimating the pseudo code and subcarrier time delay, the observations still contain unknown integer ambiguity and cannot be directly used for standard single-point positioning solution. Moreover, the error characteristic analysis and correction model research on the broadband subcarrier observation value is imperfect, and an accurate positioning model capable of fully exerting the high-precision potential of the broadband subcarrier observation value is lacking. In addition, if the broadband signal is subjected to full-bandwidth receiving and two-dimensional tracking, the receiver faces extremely high front-end sampling rate requirements and real-time calculation load, and a baseband processing architecture needs to be reconstructed, so that the implementation difficulty and cost are remarkably improved. Therefore, how to stably generate high-precision subcarrier observations of wideband signals based on a traditional or moderately improved tracking loop structure and to construct an effective positioning model to fully release the precision advantages thereof has become an important technical problem to be solved in the field of GNSS positioning. Disclosure of Invention The invention provides a GNSS standard single-point positioning method and system based on subcarrier observation value reconstruction, which are used for solving the defects of high processing difficulty and high implementation complexity of the GNSS standard single-point positioning method in the prior art, so as to reduce the application and popularization difficulty of subcarrier positioning technology and improve the GNSS standard single-point positioning performance. In a first aspect, the present invention provides a GNSS standard single point positioning method based on subcarrier observation reconstruction, including: Receiving GNSS broadband signal intermediate frequency data, respectively tracking an upper sideband signal and a lower sideband signal of the GNSS broadband signal, and respectively generating pseudo-range observation values and carrier phase observation values of the upper sideband signal and the lower sideband signal; Reconstructing a subcarrier phase observation value and a carrier phase observation value of the GNSS broadband signal in an observation domain according to the carrier phase observation values of the upper sideband signal and the lower sideband signal, and reconstructing a pseudo-range observation value of the GNSS broadband signal in the observation domain; p