The Variant Reguarity of Ionospheric Vertical Total Electron Content in Hong Kong Area

In this paper,an assessment of measured ionospheric vertical total electron content (VEC) in Hong Kong area based on dual GPS data which are from the Hong Kong DGPS universal reference station is presented. The variances of VEC on four seasons in one year are given, and the variant regularity of VEC in one day is also analyzed. It is favorable for building a practical model of ionosphere in Hong Kong area.