Accuracy assessment of single and double difference models for the single epoch GPS compass

With multi-antenna synchronized global navigation satellite system (GNSS) receivers, the single difference (SD) between two antennas is able to eliminate both satellite and receiver clock error, thus it becomes necessary to reconsider the equivalency problem between the SD and double difference (DD) models. In this paper, we quantitatively compared the formal uncertainties and dispersions between multiple SD models and the DD model, and also carried out static and kinematic short baseline experiments. The theoretical and experimental results show that under a non-common clock scheme the SD and DD model are equivalent. Under a common clock scheme, if we estimate stochastic uncalibrated phase delay (UPD) parameters every epoch, this SD model is still equivalent to the DD model, but if we estimate only one UPD parameter for all epochs or take it as a known constant, the SD (here called SD2) and DD models are no longer equivalent. For the vertical component of baseline solutions, the formal uncertainties of the SD2 model are two times smaller than those of the DD model, and the dispersions of the SD2 model are even more than twice smaller than those of the DD model. In addition, to obtain baseline solutions, the SD2 model requires a minimum of three satellites, while the DD model requires a minimum of four satellites, which makes the SD2 more advantageous in attitude determination under sheltered environments.

Section: Theoretical Analysissupporting

confidence: 90%

Δ false(L^{i} - L_{0}^{i} false) = A^{i} δ b + ε^{i}

…”

Section: Theoretical Analysismentioning

confidence: 99%

Section: Theoretical Analysismentioning

confidence: 99%

See 1 more Smart Citation

Formal Uncertainty and Dispersion of Single and Double Difference Models for GNSS-Based Attitude Determination

Chen

Dong

et al. 2017

“…When the baseline length is fixed, the baseline vector can be expressed as the nonlinear function of yaw and pitch [ 31 , 32 ]. The nonlinear equations are linearized as:

where the given Taylor point of expansion is at the INS attitude

.…”

Section: Improved Attitude Determination Methods For Single Frequenmentioning

confidence: 99%

A Performance Improvement Method for Low-Cost Land Vehicle GPS/MEMS-INS Attitude Determination

Qin

et al. 2015

Self Cite

Global positioning system (GPS) technology is well suited for attitude determination. However, in land vehicle application, low-cost single frequency GPS receivers which have low measurement quality are often used, and external factors such as multipath and low satellite visibility in the densely built-up urban environment further degrade the quality of the GPS measurements. Due to the low-quality receivers used and the challenging urban environment, the success rate of the single epoch ambiguity resolution for dynamic attitude determination is usually quite low. In this paper, a micro-electro-mechanical system (MEMS)—inertial navigation system (INS)-aided ambiguity resolution method is proposed to improve the GPS attitude determination performance, which is particularly suitable for land vehicle attitude determination. First, the INS calculated baseline vector is augmented with the GPS carrier phase and code measurements. This improves the ambiguity dilution of precision (ADOP), resulting in better quality of the unconstrained float solution. Second, the undesirable float solutions caused by large measurement errors are further filtered and replaced using the INS-aided ambiguity function method (AFM). The fixed solutions are then obtained by the constrained least squares ambiguity decorrelation (CLAMBDA) algorithm. Finally, the GPS/MEMS-INS integration is realized by the use of a Kalman filter. Theoretical analysis of the ADOP is given and experimental results demonstrate that our proposed method can significantly improve the quality of the float ambiguity solution, leading to high success rate and better accuracy of attitude determination.

“…An attitude determination system based on GNSS often consists of two receivers to receive the GNSS signals from independent antennae. Given that the common clock is used in the system, the satellite clock error can be removed by a single difference (SD) [ 4 ]. For a baseline length of a few meters, the orbital and atmosphere errors in Equation (1) are actually the same, so that these errors can be removed by a single difference.…”

Section: Model Of Gnss Attitude Determinationmentioning

confidence: 99%

Rotation Matrix Method Based on Ambiguity Function for GNSS Attitude Determination

Yang

Mao

Tian

2016

Global navigation satellite systems (GNSS) are well suited for attitude determination. In this study, we use the rotation matrix method to resolve the attitude angle. This method achieves better performance in reducing computational complexity and selecting satellites. The condition of the baseline length is combined with the ambiguity function method (AFM) to search for integer ambiguity, and it is validated in reducing the span of candidates. The noise error is always the key factor to the success rate. It is closely related to the satellite geometry model. In contrast to the AFM, the LAMBDA (Least-squares AMBiguity Decorrelation Adjustment) method gets better results in solving the relationship of the geometric model and the noise error. Although the AFM is more flexible, it is lack of analysis on this aspect. In this study, the influence of the satellite geometry model on the success rate is analyzed in detail. The computation error and the noise error are effectively treated. Not only is the flexibility of the AFM inherited, but the success rate is also increased. An experiment is conducted in a selected campus, and the performance is proved to be effective. Our results are based on simulated and real-time GNSS data and are applied on single-frequency processing, which is known as one of the challenging case of GNSS attitude determination.