Abstract: The incoherent scatter radar (ISR) is one of the most powerful tools to monitor the ionosphere on the ground, and can also be used to observe and investigate the space objects (like space debris etc).Starting from the Bayesian statistical inversion model, which acts as the theory foundation, we introduce the main method for the signal processing and parameter estimation. Then present the coherent and non-coherent integration method and their comparison using the measurement data, finally the errors are investigated. This paper is of importance to improve the measurement and forecasting of space debris, and shows good prospect in the beam-parking measurement of small-sized space debris by using the Qujing ISR, China.