From: An overview of GNSS remote sensing
MISSION
Total atm occs
Total ion occs
CHAMP
399,968
303,291
CNOFS
120,588
0
COSMIC
4,039,311
3,707,966
GPSMET
5,002
GPSMETSA
4,666
GRACE
273,013
132,817
METOPA
993,084
SACC
353,808
TSX
276,549
Total
6,465,989
4,144,074