Accurate node localization holds prime significance across a range of future network applications. In this letter, we present a novel scheme for instantaneous localization of Internet-of-Remote-Things (IoRT) terminals from the satellite/network side, employing a single-channel probing by a single-antenna-equipped single-orbiter. Our method measures both Round Trip Time (RTT) and Doppler shift, which aid the proposed localization scheme. A geometric framework to establish a probabilistic relationship between satellite transmit (Tx) and receive (Rx) positions with the target IoRT terminal location is proposed. The key steps of the proposed framework are summarized in an algorithmic form. Furthermore, a thorough performance analysis is also conducted where the impact of various channel and geometric parameters on the localization accuracy is investigated.Â