Effect Analysis of GNSS/INS Processing Strategy for Sufficient Utilization of Urban Environment Observations

Abstract

The occlusion of buildings in urban environments leads to the intermittent reception of satellite signals, which limits the utilization of observations. This subsequently results in a decline of the positioning and attitude accuracy of Global Navigation Satellite System (GNSS)/Inertial Navigation System (INS) integrated system (GNSS/INS). This study implements a smooth post-processing strategy based on a tightly coupled differential GNSS/INS. Specifically, this strategy used the INS-estimated position to reinitialize integer ambiguity. The GNSS raw observations were input into the Kalman filter to update the measurement. The Rauch–Tung–Striebel smoothing (RTSS) algorithm was used to process the observations of the entire period. This study analyzed the performance of loosely coupled and tightly coupled systems in an urban environment and the improvement of the RTSS algorithm on the navigation solution from the perspective of fully mining the observations. The experimental results of the simulation data and real data show that, compared with the traditional tightly coupled processing strategy which does not use INS-aided integer ambiguity resolution and RTSS algorithm, the strategy in this study sufficiently utilized INS observations and GNSS observations to effectively improve the accuracy of positioning and attitude and ensure the continuity of navigation results in an obstructed environment.

A Review of Mobile Mapping Systems: From Sensors to Applications

“…The traditional DGPS method achieves submeter accuracy in the horizontal position, while with much more advanced techniques and solvers, the RTK-GPS, as a type of DGPS, can achieve centimeter-level accuracy in three dimensions. However, these achievable accuracy measures are conditioned to open areas, while when collecting 3D data in dense urban areas with tall buildings or indoor environments, the GNSS signal can be largely impacted by the occlusions and the resulting measurements can be inaccurate [32], thus, it requires other complimentary sensors when operating under such conditions. In general, the positioning platform of an MMS is expected to achieve an accuracy of 5-50 mm at speed that can reach the maximum speed of highways (120-130 km/h) when considering the integration of complementary sensors.…”

A novel ambiguity resolution model of BeiDou navigation satellite system/inertial navigation system tightly coupled for kinematic-to-kinematic precise relative positioning

“…Afterwards, R k , P k, kÀ1 are used to update R k , P k, kÀ1 in filtering equation (14). When robust adaptive filtering is realized, the more accurate ambiguity floats are obtained.…”

“…Therefore, the GNSS/INS integrated system can maintain high-precision navigation under complex dynamic environments. [14][15][16][17] There are two representative GNSS/INS integration methods with loosely coupled (LC) and tightly coupled (TC). Among them, the LC method is simple implementation but unreliability with less than four visible satellites; 18 while the TC method offers theoretical soundness and high accuracy, which is used in various fields such as airborne navigation, intelligent transportation, and precision agriculture.…”

Improved Adaptive Iterated Extended Kalman Filter for燝NSS/INS/UWB-Integrated Fixed-Point Positioning

“…And the most widely used example is the loosely-integrated localization model. For example, the GNSS/INS loosely processing strategy has been proposed in [5]. In [6], the loosely-integrated model is investigated, and then used to the indoor pedestrian tracking.…”