System approach to the choice of capacity of a high-speed radio data link for modern Earth remote sensing spacecraft

Abstract

The main principles of choosing the capacity of a high-speed radio data link for modern Earth remote sensing spacecraft are discussed in the paper. The following points are taken into account: overfilling of the onboard memory storage device; duration of communication sessions between the spacecraft and the downlink point; the required bandwidth and the reliability of the radio data link. Mathematical restrictions for the conditions of the overflow of the on-board memory storage of target information and the amount of information transmitted to the downlink points during a communication session between the spacecraft and the downlink point are specified. An expression is proposed for the estimation of radio data link capacity on the basis of the Shannon formula with account for the energy relations for satellite communication links, the required width of the passband and the probability of data transmission error. The influence of the probability of the information transmission error and the main parameters of the radio signal (the speed of protective coding and the phase deviation) on the value of high-speed radio data link capacity is analyzed. Changes in radio data link capacity in retrospect for the years immediately ahead are analyzed in accordance with the predicted value of the required volume of space information of Earth remote sensing for radio data links of different reliability.