High-precision carrier phase timing method with single communication satellite and the test campaign

GPS Solutions ◽  
2021 ◽  
Vol 25 (2) ◽  
Author(s):  
Yang Zhang ◽  
Lingling Xu ◽  
Yu Su ◽  
Wenfang Jing ◽  
Xiaochun Lu
Keyword(s):  
High Precision ◽  
Carrier Phase ◽  
Communication Satellite

Carrier-Phase Differential GPS/INS Integrated Navigation System

2013 ◽  
Vol 760-762 ◽  
pp. 457-461
Author(s):  
Lu Zhang ◽  
Gong Liu Yang
Keyword(s):  
High Precision ◽  
Navigation System ◽  
Carrier Phase ◽  
Closed Loop ◽  
Measurement Data ◽  
Integrated Navigation ◽  
Differential Gps ◽  
Actual Measurement ◽  
Integrated Navigation System ◽  
Arm Processor

According to high accuracy demand in the measurement field, this paper designs a high precision inertial measurement system by using DSP and ARM processor to realize carrier-phase differential GPS/INS integrated navigation. This paper chooses Kalman filter to estimate the systematic error, uses closed loop method to correct, and carries out carrier-phase differential GPS/INS data fusion. Through manipulating actual measurement data, the integrated navigation results indicate that position accuracy reaches cm level; velocity accuracy reaches cm/s level and attitude achieves high precision. The experiment proves the feasibility and effectiveness of carrier-phase differential GPS/INS integrated navigation system.

scholarly journals On the feasibility of resolving Android GNSS carrier-phase ambiguities

2020 ◽  
Author(s):  
Jianghui Geng ◽  
Guangcai Li
Keyword(s):  
High Precision ◽  
Patch Antenna ◽  
Carrier Phase ◽  
Low Cost ◽  
Integer Ambiguity ◽  
Smart Devices ◽  
Ambiguity Fixing ◽  
Gnss Ambiguity Resolution ◽  
Phase Data ◽  
Carrier Phase Tracking

High-precision navigation using low-cost handsets has profound potential for mass-market applications, which has been being boosted by the release of raw GNSS data from Google Android smart devices. However, integer ambiguity fixing for centimeter-level GNSS positioning is prevented by the unaligned chipset initial phase biases (IPBs) found within Android carrier-phase data. In this study, we thus investigate the temporal behaviors of those chipset IPBs using zero baselines where smart devices are linked to external survey-grade antennas, and find that the IPBs are generally stable over time as the mean standard deviation of single-epoch IPB estimates derived from continuous carrier-phase data is as low as 0.04 cycles for all satellites. Unfortunately, these chipset IPBs differ randomly among satellites and change unpredictably if carrier-phase signals are re-tracked, discouragingly suggesting that the chipset IPBs cannot be pre-calibrated or even calibrated on the fly. We therefore have to presumably correct for them in a post-processing manner with the goal of inspecting the potential of Android GNSS ambiguity resolution if hopefully the IPBs can be gone. For a vehicle-borne Nexus 9 tablet with respect to a survey-grade receiver located 100-2000 m away, we achieve the first ambiguity-fixed solution within 321 s and finally 51.6% of all epochs are resolved; the ambiguity-fixed epochs can achieve a positioning accuracy of 1.4, 2.2 and 3.6 cm for the east, north and up components, respectively, showing an improvement of 30%-80% compared to the ambiguity-float solutions. While all smart devices above are connected to external survey-grade antennas, we find that a Xiaomi 8 smartphone can be coupled effectively with a miniaturized portable patch antenna, and then achieve commensurate carrier-phase tracking and ambiguity-fixing performance to those of a commercial μ-blox receiver with its dedicated patch antenna. This is encouraging since a compact and inexpensive patch antenna paired with smart devices can promote the democratization of high-precision GNSS.

scholarly journals Phase Ambiguity Resolution Method Using Processing of Code and Carrier Phase Pseudoranges in a Kalman-Type Filter

2021 ◽  
Vol 8 (3) ◽  
pp. 72-80
Author(s):  
V. E. Vovasov ◽  
◽  
R. B. Mazepa ◽  
D. A. Sukharev ◽  
A. V. Voropaeva ◽  
...  
Keyword(s):  
High Precision ◽  
Ambiguity Resolution ◽  
Carrier Phase ◽  
Phase Ambiguity ◽  
Phase Measurements ◽  
Phase Ambiguity Resolution ◽  
Code Pseudorange ◽  
L1 And L2 ◽  
Base Network ◽  
Observation Period

The main problem of implementing high-precision pseudoranges by carrier phase lies in their ambiguity associated with the ambiguity of the phase measurements of the navigation receiver. Thus, the development of new methods for phase ambiguity resolution becomes a very important element of high-precision positioning. The paper considers relative methods for estimating the coordinates of a stationary object that involve the use of both user and base (network in the case of a network of base receivers) receivers with precisely known coordinates located at a distance of several thousand kilometers from each other. We propose an algorithm for phase ambiguity resolution (integer type) based on the use of a Kalman-type filter (KTF), which receives ionosphere-free combinations of code and carrier phase pseudoranges. It is shown that traditional methods of ambiguity resolution require a significant observation period (about 2,000 seconds). We propose a method for evaluating the linear combination of phase ambiguities in the L1 and L2 bands obtained from instantaneous phase measurements. Its application along with the estimation of KTF parameters makes it possible to resolve phase ambiguities from as early as 50 seconds of observation. Set forth are the results of an experiment, in which code pseudorange measurements are used prior to the resolution of phase ambiguities and carrier phase pseudorange measurements are used after ambiguity resolution.

scholarly journals A Holistic Approach to Guarantee the Reliability of Positioning Based on Carrier Phase for Indoor Pseudolite

2020 ◽  
Vol 10 (4) ◽  
pp. 1199 ◽  
Author(s):  
Yinzhi Zhao ◽  
Jiming Guo ◽  
Jingui Zou ◽  
Peng Zhang ◽  
Di Zhang ◽  
...  
Keyword(s):  
Kalman Filter ◽  
High Precision ◽  
Carrier Phase ◽  
Holistic Approach ◽  
Indoor Positioning ◽  
Test Statistics ◽  
Error Sources ◽  
Integrity Monitoring ◽  
Dynamic Experiments ◽  
Probability Of Missed Detection

The integrity monitoring algorithm based on pseudorange observations has been widely used outdoors and plays an important role in ensuring the reliability of positioning. However, pseudorange observations are greatly affected by the error sources such as multipath, clock drift, and noise in indoor pseudolite system, thus the pseudorange observations cannot be applied to high-precision indoor positioning. In general, double differenced (DD) carrier phase observations are used to obtain a high-precision indoor positioning result. What’s more, the carrier phase-based integrity monitoring (CRAIM) algorithm is applied to identify and exclude potential faults of the pseudolites. In this article, a holistic method is proposed to ensure the accuracy and reliability of positioning results. Firstly, if the reference pseudolite operates normally, extended Kalman filter is used for parameter estimation on the premise that the number of common pseudolites meets positioning requirements. Secondly, the innovation sequence in the Kalman filter is applied to construct test statistics and the corresponding threshold is determined from the Chi distribution with a given probability of false alert. The pseudolitehorizontal protection level (HPL) is calculated by the threshold and a prior probability of missed detection. Finally, compared the test statistics with the threshold to exclude the faultypseudolite for the reliability of positioning. The experiment results show that the proposed method improves the accuracy and stability of the results through faults detection and exclusion. This method ensures accuracies at the centimeter level for dynamic experiments and millimeter levels for static ones.

High-Precision Kinematic Satellite and Doppler Aided Inertial Navigation System

2010 ◽  
Vol 64 (1) ◽  
pp. 91-108 ◽  
Author(s):  
Ranjan Vepa ◽  
Amzari Zhahir
Keyword(s):  
High Precision ◽  
Navigation System ◽  
Carrier Phase ◽  
Inertial Navigation System ◽  
Unscented Kalman Filter ◽  
Inertial Navigation ◽  
Satellite Navigation ◽  
Initial Alignment ◽  
Phase Measurements ◽  
Satellite Navigation System

In this paper an adaptive unscented Kalman filter based mixing filter is used to develop a high-precision kinematic satellite aided inertial navigation system with a modern receiver that incorporates carrier phase smoothing and ambiguity resolution. Using carrier phase measurements with multiple antennas, in addition to a set of typical pseudo-range estimates that can be obtained from a satellite navigation system such as GPS or GLONASS, the feasibility of generating high precision estimates of the typical outputs from an inertial navigation system is demonstrated. The methodology may be developed as a stand-alone system or employed in conjunction with a traditional strapped down inertial navigation system for purposes of initial alignment. Moreover the feasibility of employing adaptive mixing facilitates the possibility of using the system in an interoperable fashion with satellite navigation measurements.

Research on the High-Precision Phase Simulation of DSSS Signal

2013 ◽  
Vol 712-715 ◽  
pp. 1987-1994
Author(s):  
Shi Wen Li ◽  
Peng Xu
Keyword(s):  
High Precision ◽  
Spread Spectrum ◽  
Carrier Phase ◽  
Satellite System ◽  
Direct Sequence Spread Spectrum ◽  
Direct Sequence ◽  
Frequency Signal ◽  
Generating Method ◽  
Precision Phase ◽  
Global Navigation Satellite

In order to meet the developing requirements of the high-precision GNSS(Global Navigation Satellite System) receiver and spread-spectrum TT&C equipment, we researched high-precision simulating technology of DSSS (Direct Sequence Spread Spectrum) signal and proposed simulating technology of carrier phase and pseudo code phase based on correction technology online. This technology avoids sacrificing implement slice to improve phase precision and can simulate relative motion between receiver and object. In this paper, high-precision generating method of digital middle frequency signal is focused on. The effectiveness of this algorithm has been corroborated by theoretical analysis, simulation and applied to some spaceflight simulator successfully.

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