Application of the PJ and NPS evaporation duct models over the South China Sea (SCS) in winter.

Shaobo Yang,Xin He,Xingfei Li,Chao Wu,Ying Zhong,Vijai Gupta

doi:10.1371/journal.pone.0172284

Abstract

The detection of duct height has a significant effect on marine radar or wireless apparatus applications. The paper presents two models to verify the adaptation of evaporation duct models in the SCS in winter. A meteorological gradient instrument used to measure evaporation ducts was fabricated using hydrological and meteorological sensors at different heights. An experiment on the adaptive characteristics of evaporation duct models was carried out over the SCS. The heights of the evaporation ducts were measured by means of log-linear fit, Paulus-Jeske (PJ) and Naval Postgraduate School (NPS) models. The results showed that NPS model offered significant advantages in stability compared with the PJ model. According the collected data computed by the NPS model, the mean deviation (MD) was -1.7 m, and the Standard Deviation (STD) of the MD was 0.8 m compared with the true value. The NPS model may be more suitable for estimating the evaporation duct height in the SCS in winter due to its simpler system characteristics compared with meteorological gradient instruments.

Highlights

Atmospheric optical refraction has attracted considerable attention in the last few years in atmospheric science, physics, and electronics and so on
Ducts occasionally support the normal propagation of radar signals and can cause signal distortion and attenuation, which be depended on the atmospheric refractivity and on its close relation to atmospheric factors such as moisture, wind, air and sea surface temperatures (SST)
Naval Postgraduate School (NPS) calculates the evaporation duct based on the Monin-Obukhov Similarity Theory, which is different from the PJ model and the modified refractivity profile

Summary

Introduction

Atmospheric optical refraction has attracted considerable attention in the last few years in atmospheric science, physics, and electronics and so on. In 2009, Yang K D used NPS model to calculate evaporation duct height based on the National Centers for Environmental Prediction data. Evaporation duct models based on iron towers are used widely in practice because of their low cost, high accuracy and real-time data compared with the other methods.

Results

Conclusion