Higher-Order Ionospheric Effects on the GPS Double Difference
Observation and Baseline Vectors
1 CCCC Second Harbor Consultants Co, Ltd., 555 Minzhu Road,Wuhan 430071, China
2 School of Geodesy and Geomatics,Wuhan University,129 Luoyu Road, Wuhan 430079, China
Abstract Ionospheric 2nd-order and 3rd-order items of GPS observation are calculated by RINEX HO software. On this basis, higher-order ionospheric delay (ΔIH)p,qi,g of the GPS double difference observation is determined. The relationship between (ΔIH)p,qi,g and geomagnetic latitude, baseline length, baseline direction and the sun's activity level are studied. Then, under the assumption that other conditions are the same, the Bernese 5.0 software are applied to the baseline solution for the observed values, both under and not under the higher-order ionospheric delay correction. Higher-order ionospheric effects on baseline vectors ΔbH are calculated. The results show that the value of ΔbH is very small and can be ignored in the general case. ΔbH has no exact relationship with the factors such as baseline length, solar activity level and so on, but with the decrease of the time, ΔbH will increase.
