Effects of the tropospheric horizontal gradients on GPS coordinates estimation: a case study for severe storms conditions

GRAFFIGNA, VICTORIA; HERNÁNDEZ-PAJARES, MANUEL; GENDE, MAURICIO

Viena

Conferencia; EGU 2018; 2018

European Geosciences Union

The neutral layer of the atmosphere causes a vertical delay on the GNSS signals typically of about 2 meters, andup to one order of magnitude more in slant directions. Over the last past decade there has been shown that thisquantity has an azimuthally asymmetric behavior that can systematically affect the precise positioning as well aslead to misinterpreting the repeatability of the site?s coordinates. We are currently showing on this present workhow this parameter is estimated with an in-house software and its performance is being compared to results fromJPL?s software (GIPSY 6.2).This scenario will be applied on a case study for the recent Harvey hurricane where gradients, i.e. az-imuthal ZTD variations, of up to 1 centimeter have been found. Moreover, we are showing the impact on thecoordinates estimation when different processing strategies such as PPP (static and kinematic) or relative precisepositioning are applied. The conclusions confirm the convenience of estimating ZTD horizontal gradients duringstrong weather events for avoiding a degradation of the quality of the precise GPS positioning.