Global Navigation Satellite System (GNSS) Radio Occultation (RO) is an excellent remote sensing technique for sounding the atmosphere. GNSS satellites send signals through the atmosphere of the Earth, and a GNSS receiver mounted on a Low Earth Orbit (LEO) satellite receives them. Through GNSS RO, refractivity will be estimated, which is considered the main parameter in the determination of planetary boundary layer height (PBLH). This paper presents the use of GNSS RO for the detection of PBLH over Egypt.

PBLH is an important parameter to characterize the lower troposphere and plays a significant role in air quality adjustment. GNSS RO can be used to detect PBLH because of its high spatial and temporal coverage. The estimated PBLHs from GNSS RO are compared with PBLH estimated from the European Centre for Medium-range Weather Forecasts (ECMWF) model. This paper introduces the variation of the PBLH over Egypt for the period from 2006 to 2019. GNSS RO PBLH distribution is consistent with that of ECMWF. The maximum value of PBLH (4.75 km) occurs in the summer and its minimum value (0.43 km) occurs in the winter. PBLH shows higher values around 15:00 LT (late afternoon) in Egypt. Our results show that GNSS RO is a promising technique for sensing the atmosphere's dynamics.

全球导航卫星系统 (GNSS) 无线电掩星 (RO) 是一种用于探测大气的优秀遥感技术。GNSS 卫星通过地球大气层发送信号，安装在低地球轨道 (LEO) 卫星上的 GNSS 接收器接收信号。通过 GNSS RO，将估计折射率，这被认为是确定行星边界层高度 (PBLH) 的主要参数。本文介绍了使用 GNSS RO 探测埃及上空的 PBLH。

PBLH是表征对流层低层的重要参数，在空气质量调节中起着重要作用。GNSS RO 可用于检测 PBLH，因为它具有较高的空间和时间覆盖率。将 GNSS RO 估算的 PBLH 与欧洲中期天气预报中心 (ECMWF) 模型估算的 PBLH 进行比较。本文介绍了埃及2006-2019年PBLH的变化情况。GNSS RO PBLH分布与ECMWF一致。PBLH的最大值（4.75 km）出现在夏季，最小值（0.43 km）出现在冬季。PBLH 在埃及的 LT 15:00（下午晚些时候）左右显示出更高的值。我们的结果表明，GNSS RO 是一种很有前途的大气动态检测技术。