Spherical and oblate Earth conical shadow models for LEO satellites: Applications and comparisons with real time data and STK to IRS satellites

This article reports two conical shadow models: a spherical Earth conical shadow model (SECSM) and an oblate Earth conical shadow model (OECSM), and their comparative study to predict umbra and penumbra shadow regions for the low Earth orbiting (LEO) satellites. First model is described using a projection map technique considering the spherical shape of the Earth whereas the second model is illustrated using the line of intersection method for the oblate Earth. Both models have been implemented to four Indian Remote Sensing (IRS) satellites: Oceansat-2, Resourcesat-2, Cartosat-2A and Meghatropics-1. Computed results are compared well with the real time data and the commercial AGI package, Systems Tool Kit (STK).