RT Journal Article
SR Electronic
T1 Ionospheric spatial decorrelation assessment for GBAS daytime operations in Brazil
JF NAVIGATION: Journal of the Institute of Navigation
JO NAVIGATION
FD Institute of Navigation
SP 391
OP 404
DO 10.1002/navi.418
VO 68
IS 2
A1 Hyeyeon Chang
A1 Moonseok Yoon
A1 Sam Pullen
A1 Leonardo Marini-Pereira
A1 Jiyun Lee
YR 2021
UL https://navi.ion.org/content/68/2/391.abstract
AB Extensive ionospheric studies were conducted to support the initial phase of system design approval for the existing SLS-4000 GBAS installed at Antonio Carlos Jobim International Airport (formerly Galeão International Airport) (GIG) in Rio de Janeiro, Brazil. This paper focuses on determining the broadcast value of the standard deviation of vertical ionospheric gradients (or 𝜎vig) that is required to bound ionospheric spatial gradients in Brazil under nominal conditions during daytime hours. The time-step method is useful for gaining sufficient samples at distances less than the physical separation distance of ground stations and was utilized to estimate ionospheric spatial gradients. A new method called “geometric similarity” was developed to estimate ionospheric temporal gradients and evaluate the temporal effect added to the bounding 𝜎vig values. As a result, a 𝜎vig of 13 mm/km, including a temporal gradient contribution of approximately 2 mm/km, is conservative enough to bound ionospheric spatial decorrelation for daytime GBAS operations in Brazil.