Instantaneous GPS–Galileo Attitude Determination: Single-Frequency Performance in Satellite-Deprived Environments

Abstract

New and modernized global navigation satellite systems (GNSSs) are paving the way for an increasing number of applications in positioning, navigation, and timing (PNT). A combined GNSS constellation will significantly increase the number of visible satellites and, thus, will improve the geometry of observed satellites, enabling improvements in navigation solution availability, reliability, and accuracy. In this paper, a global positioning system (GPS)+Galileo robustness analysis is carried out for instantaneous single-frequency GNSS attitude determination. Precise attitude determination using multiple GNSS antennas mounted on a platform relies on successful resolution of the integer carrier-phase ambiguities. The multivariate-constrained least squares ambiguity decorrelation adjustment (MC-LAMBDA) method has been developed to resolve the integer ambiguities of the nonlinearly constrained GNSS attitude model that incorporates the known antenna geometry. In this paper, the method is used to analyze the attitude determination performance of a combined GPS+Galileo system. Special attention is thereby given to the GPS and Galileo intersystem biases (ISBs). The attitude determination performance is evaluated using GPS/Galileo data sets from a hardware-in-the-loop experiment and two realdata campaigns. In the hardware-in-the-loop experiment, a full GPS/Galileo constellation is simulated, and performance analyses are carried out under various satellite-deprived environments, such as urban canyons, open pits, and other satellite outages. In the first real-data experiment, single-frequency GPS data, combined with the data of Galileo in-orbit validation element (GIOVE) satellites GIOVE-A/GIOVE-B (the two experimental Galileo satellites), are used to analyze the two constellation attitude solutions. In the second real-data experiment, we present the results based on single-frequency data from one of the Galileo IOV satellites, combined with the data of GIOVE-A and GPS. We demonstrate and quantify the improved availability, reliability, and accuracy of attitude determination using the combined constellation.

Instantaneous GPS/Galileo/QZSS/SBAS Attitude Determination: A Single-Frequency (L1/E1) Robustness Analysis under Constrained Environments

“…Analyses of PNT solutions using a dual system (GPS with one of the other systems) have been reported in various studies. The performance of the combined GPS-Galileo PNT solutions has been analyzed in [23][24][25][26][27]. The benefit of augmenting GPS with QZSS is demonstrated in [28].…”

Attitude Determination Algorithms through Accelerometers, GNSS Sensors, and Gravity Vector Estimator

“…Newton-Euler equations are used in order to estimate angular velocity (see (9)), where I B is the rocket inertia tensor defined in (10), M ai are the passive aerodynamic moments which actuate on the projectile, and M control are the moments generated by control surfaces. Passive aerodynamic moments are defined in (11), where O is the overturn moment, P M is the pitch damping moment, M M is the Magnus moment, and S is the spin damping moment.…”

“…The underlying theory and advanced algorithms for much of the above-referred integer-ambiguity-resolved carrier-phase GNSS attitude determination methods can be found in [7][8][9]. Multi-GNSS developments of integrating GNSS systems for attitude determination are stated in [10,11].…”

Dual frequency long-short baseline ambiguity resolution for GNSS attitude determination

“…The baseline length is a readily available and widely used constraint [1]. As most of the recent attitude determination AR methods search in the ambiguity domain [2], such as C-LAMBDA and MC-LAMBDA [3][4][5][6][7]. In challenging environments, the search-based AR methods suffer from serious pseudo-range multipath and bad satellites geometry.…”