Carrier smoothing code pseudorange technology-based dynamic attitude positioning method

Abstract

The invention discloses a carrier smoothing code pseudorange technology-based dynamic attitude positioning algorithm method, which comprises the following steps of: (1) detecting whether cycle slip occurs in the current epoch by using a three-difference method, if so, using the code observation of the current epoch, otherwise, acquiring the smoothed code observation by using Hatch filtering and recording the smoothing window length k; (2) solving the floating solution of the integer ambiguity and the variance-covariance matrix of the floating solution by utilizing the code observation and the code observation of the current epoch; (3) taking the floating solution of the integer ambiguity and the variance-covariance matrix of the floating solution as initial parameters, substituting the initial parameters into an LAMBDA algorithm for solving the fixed solution of the ambiguity, and acquiring former N ambiguity candidate values; and (4) performing the ambiguity test on the former N ambiguity candidate values in turn, until the ambiguity candidate solution meeting the constraint condition is found, and solving the obtained attitude angle. The carrier smoothing code pseudorange technology-based dynamic attitude positioning algorithm method does not have the problem of initialization time, can be effectively used for real-time dynamic attitude measurement, and can self-adaptively regulate the smoothing window length and the ambiguity candidate solution space aiming at the occurrence of the cycle slip. Therefore, the success rate and the overall efficiency of the algorithm are improved.

Description

technical field [0001] The invention relates to a dynamic attitude determination method based on carrier smooth code pseudo-range technology, which belongs to the technical field of satellite orientation and attitude determination. Background technique [0002] Attitude measurement is generally used on high-dynamic carriers such as satellites, spacecraft, manned aircraft, drones, ships, and automobiles. These carriers require attitude measurement systems to have the characteristics of high precision, strong real-time performance, and easy installation. High-precision real-time attitude calculation system has important strategic significance and application value for national defense and aerospace fields. [0003] The Global Positioning System (GPS) has global, all-weather and continuous precision three-dimensional positioning capabilities. In the past ten years, GPS has been widely used in various fields. GPS precision positioning includes two major directions, that is, si...

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Problems solved by technology

[0006] At present, there are two relatively mature methods for solving the attitude of the carrier. One is the ambiguity function method (AFM). The advantage is that it can be solved in a single epoch without considering the cycle slip problem. Dr. Wang Yongquan improved this method in his doctoral thesis "Research on GPS / GLONASS Attitude Measurement under Long-term and High Dynamic Conditions", which greatly reduced the amount of calculation, but the success rate still needs to be improved; the other is the LAMBDA algorithm, which The method was originally proposed by Professor P.J.G Teunissen of Delft University of Technology. Later, many scholars carried out research and improvement, and it is widely used in academia. The advantage of the LAMBDA algorithm is that it is the most effective method for estimating the ambiguity of the whole circle. However, this method is not practical in practical applications. There are also some shortcomings. First, the LAMBDA algorithm needs to obtain the floating-point solution of the entire ambiguity and the variance-covariance matrix of the floating-point solution in advance. For a single-frequency receiver, the acquisition of the floating-point solution often requires multiple historical The observation data of one epoch needs a certain initialization time, and using multiple epochs to solve the baseline coordinates, it must be ensured that the number of satellites does not change during the solving process of each epoch, and no cycle slips occur, but the carrier is in motion. , which is inevitably blocked by various obstacles, causing the receiver to lose lock and cycle slip, or the satellite is "invisible" due to occlusion

Second, the LAMBDA algorithm is relatively mature in the static baseline attitude measurement. Since the baseline coordinates remain unchanged at any time, it is easy to use the least squares to solve the floating point solution and the LAMBDA algorithm to estimate the initial integer ambiguity, usually within a few minutes Solve the baseline coordinates and attitude angles, but in dynamic situations, the baseline coordinates correspond to different unknowns at different times, the classical least squares method and the LAMBDA algorithm cannot be directly applied, and the current existing methods require a long initialization time. The process of completing the convergence of the ambiguity to the integer solution is not conducive to practical engineering applications; third, the success rate of the LAMBDA algorithm for solving the carrier attitude is sensitive to the accuracy of the floating-point solution, and the higher the accuracy of the floating-point solution, the higher the success rate; Fourth, Using the LAMBDA algorithm, only using the carrier phase observation to solve it in a single epoch, will encounter the rank deficiency problem of the observation equation, and cannot obtain the ambiguity floating point solution

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