Space debris with size larger than 1 cm poses a threat to spacecraft. Recently, space debris surveillance, tracking and early warning become far more urgent than ever before owing to the explosive growth of the number of debris. At the base of these problems is how to determine the visibility of debris to observation equipment, which will be discussed in this study. The statistics related to the orbital altitude, inclination and eccentricity of space debris are presented first, and then the principles of orbital parameter design of the space-borne radar (SBR) are given. Next, systemic parameters of SBR, such as wavelength, antenna type, are determined upon the observation aim. Detectable debris subset is preliminarily selected in accordance with some constraints. At last, based on the simplified general perturbations (SGP4) model, the range and velocity vectors of debris to SBR at specific time are calculated. Another expression form of relative position between debris and radar, range, azimuth and elevation (RAE) course is obtained by means of coordinate rotation which can be accomplished by directing projection or rotational matrix. The RAE data guide file can be used to carry on guidance tracking. Furthermore, the conversion accuracy of two different coordinate transformation methods is also analysed.

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Noise Frequency Modulated (NFM) interference causes a disaster to almost all types of Radar systems. The echo signal and the interference are overlapped and because of strong energy of the NFM interference nothing could be detected except the interference in the Radar receiver system. Up to now no good method against NFM has been declared, conventional methods are based on the passive Radar to track the interference source which are not applicable under most conditions. Here a novel anti-noise FM method is proposed to suppress the NFM interference, the method multiply the mixed signal two times by different reference signals. The principle and some key factors of the new method are analyzed in detail and some rules for parameters designing are given. What's more, results show that the method can eradicate NFM effectively.