Based on other satellites

Kotova, G. A., Bezrukikh, V. V., Verigin, M. I., & Lezhen, L. A. (2002). Temperature and density variations in the dusk and dawn plasmasphere as observed by interball tail in 1999 - 2000. Advances in Space Research, 30(7), 1831-1834. https://doi.org/10.1016/s0273-1177(02)00458-1

Kotova, G. A., Bezrukikh, V. V., Verigin, M. I., Lezhen, L. A., & Barabanov, N. A. (2002). Interball 1/alpha 3 cold plasma measurements in the evening plasmasphere: Quite and disturbed magnetic conditions. Advances in Space Research, 30(10), 2313-2318. https://doi.org/10.1016/s0273-1177(02)80256-3