Wenfeng Nie

TL;DR: This paper designs a LEO-based optimal global navigation and augmentation constellations designed by a non-dominated sorting genetic algorithm III (NSGA-III) and genetic algorithm (GA) and proves that the computation efficiency of the constellation design can be considerably improved by using master–slave parallel computing.

TL;DR: Evaluation of PWV values derived by 268 Global Navigation Satellite Systems stations around the world covering the period from 2016 to 2018 indicates that the absolute accuracies of five reanalysis products are highest in the polar regions and lowest in the tropics.

TL;DR: Evaluating the performance of ZTD derived from ERA5 reanalysis data over China using 219 GNSS stations of the Crustal Movement Observation Network of China (CMONOC) covering the period from 2015 to 2016 finds that the ERA5 ZTD over China has obvious seasonality, with higher accuracy in winter and lower accuracy in summer.

TL;DR: To evaluate the future capacity for repetitive GNSS-R observations, a GNSS satellite selection method is proposed and a simulation of the orbit of eight-satellite LEO and partial multi-GNSS constellations shows that the multi- GNSS -R system has major advantages in terms of available satellite numbers and revisit times over the GPS-R system.

TL;DR: In this paper, the accuracy analysis of the undifferenced ambiguity-fixed carrier phase ionospheric observable determined from a global distribution of permanent receivers is revisited, and the results achieved are: (1) using data from an entire month within the last solar cycle maximum, the undeferenced ambiguities fixed CARI observable is found to be over one order of magnitude more accurate than the carrier phase leveled to code ionosphere observable and the raw code ionosphere observable, respectively, and (2) the remaining part of the observation errors present a sidereal