Validation of Integrated Water-Vapor Content from GNSS Data of Ground-Based Measurements

Abstract

Time series of integrated water-vapor (IWV) content for 2015–2017 at eight paired GNSS stations and solar photometry data from the AERONET network in Europe have been compared. The distance between station pairs was no more than 20 km. The average and standard deviations of discrepancies have been shown to vary seasonally. The GNSS–photometer bias in winter was from –0.61 to 0.34 mm. The IWV content in summer is overestimated by the GNSS relative to photometers by 0.52 to 2.26 mm. The standard deviation is from 1.31 to 1.64 mm with a maximum in summer and decreases to 0.49–0.86 mm in winter, which is 5–6% of IWV.