Assessment of International GNSS Service Global Ionosphere Map products over China region based on measurements from the Crustal Movement Observation Network of China

Abstract

Map (GIM) products over China region is systemically evaluated.• Marked dependencies on local time and latitude, coupled with seasonal variations, are evidenced in errors within the IGS-GIM products.• The sparse measurement coverage, compounded by China's distinct geomagnetic topology, induces uncertainties in the IGS-GIM products.