remote sensing Article Enhanced Neural Network Model for Worldwide Estimation of Weighted Mean Temperature Fengyang Long 1 , Chengfa Gao 1,*, Yuxiang Yan 1 and Jinling Wang 2 1 School of Transportation, Southeast University, Nanjing 211189, China;
[email protected] (F.L.);
[email protected] (Y.Y.) 2 School of Civil and Environmental Engineering, University of New South Wales, Sydney, NSW 2052, Australia;
[email protected] * Correspondence:
[email protected] Abstract: Precise modeling of weighted mean temperature (Tm) is critical for realizing real-time conversion from zenith wet delay (ZWD) to precipitation water vapor (PWV) in Global Navigation Satellite System (GNSS) meteorology applications. The empirical Tm models developed by neural network techniques have been proved to have better performances on the global scale; they also have fewer model parameters and are thus easy to operate. This paper aims to further deepen the research of Tm modeling with the neural network, and expand the application scope of Tm models and provide global users with more solutions for the real-time acquisition of Tm. An enhanced neural network Tm model (ENNTm) has been developed with the radiosonde data distributed globally. Compared with other empirical models, the ENNTm has some advanced features in both model design and model performance, Firstly, the data for modeling cover the whole troposphere rather than just near the Earth’s surface; secondly, the ensemble learning was employed to weaken the impact of sample disturbance on model performance and elaborate data preprocessing, including up-sampling and down-sampling, which was adopted to achieve better model performance on the global scale; Citation: Long, F.; Gao, C.; Yan, Y.; furthermore, the ENNTm was designed to meet the requirements of three different application Wang, J.