The new radar system of combination of the hopped-frequency with the conical scan is presented. According to the principle and expression of the conical scan hopped-frequency signal, the angle processing method in whi...The new radar system of combination of the hopped-frequency with the conical scan is presented. According to the principle and expression of the conical scan hopped-frequency signal, the angle processing method in which angle information is obtained by taking discrete Fourier transform （DFT） for the conical envelop of each scattering centre by means of high range resolution profile （HRRP） is presented, and the corresponding formula is derived. The influence of non-ideal factors, such as amplitude fluctuation noise and system noise, leakage of time and frequency domain, unstable rotation of antenna, and missile rotation, on angle-measurement precision and the possible solving methods are also focused on. The simulation results show that the combination of the hopped-frequency and conical scan system could get satisfactory angle information, which could ensure good quality when used in practical tracking radar.展开更多
An introduction of an auto-tracking antenna is given to replace the nutating conical-scankind.In tracking the signal target with linear polarization,the use of the nutating joint with complexstructure can be avoided.T...An introduction of an auto-tracking antenna is given to replace the nutating conical-scankind.In tracking the signal target with linear polarization,the use of the nutating joint with complexstructure can be avoided.The advantages are evident in economy and stability.The design principle ofthe antenna and feed is also introduced.According to this principle,the antenna has been made.Themeasured values of the feed and antenna show that the angles of the beam deviated from the antenna axisin any plane are almost the same and the polarization performances are excellent.In tracking the signal tar-get with linear polarization,the target is caught quickly and exactly,and the situation of the antenna is sta-ble.The tracking performences are satisfactory.展开更多
This paper focuses upon the novel optical conical scanning imaging working mode design for small satellites.This kind of satellite employs only one inclined optical camera achieving wide-swath imaging via a rotational...This paper focuses upon the novel optical conical scanning imaging working mode design for small satellites.This kind of satellite employs only one inclined optical camera achieving wide-swath imaging via a rotational motion about the nadir axis either by the camera or by the satellite.Three working modes are designed,i.e.,high-speed rotational mode,low-speed rotational mode,and variable-speed rotational mode.For the high-speed and low-speed working modes,the camera rotates at a constant speed and the corresponding angular velocity is derived under the consideration of guaranteed coverage and minimized overlap.To improve the system performance,an enhanced working mode taking advantages of both the high-speed rotational mode and lowspeed rotational mode is proposed.Working in this variable-speed rotational mode,the camera rotates slowly to get high-quality pictures when it works,while it rotates rapidly to reduce the energy consumption and save the storage during which period the camera is turned off to minimize the overlap.All these working modes are illustrated in detail,and numerical simulation tests are conducted to validate their effectiveness.展开更多
基金the Ministerial Level Advanced Research Foundation(040230105)
文摘The new radar system of combination of the hopped-frequency with the conical scan is presented. According to the principle and expression of the conical scan hopped-frequency signal, the angle processing method in which angle information is obtained by taking discrete Fourier transform （DFT） for the conical envelop of each scattering centre by means of high range resolution profile （HRRP） is presented, and the corresponding formula is derived. The influence of non-ideal factors, such as amplitude fluctuation noise and system noise, leakage of time and frequency domain, unstable rotation of antenna, and missile rotation, on angle-measurement precision and the possible solving methods are also focused on. The simulation results show that the combination of the hopped-frequency and conical scan system could get satisfactory angle information, which could ensure good quality when used in practical tracking radar.
文摘An introduction of an auto-tracking antenna is given to replace the nutating conical-scankind.In tracking the signal target with linear polarization,the use of the nutating joint with complexstructure can be avoided.The advantages are evident in economy and stability.The design principle ofthe antenna and feed is also introduced.According to this principle,the antenna has been made.Themeasured values of the feed and antenna show that the angles of the beam deviated from the antenna axisin any plane are almost the same and the polarization performances are excellent.In tracking the signal tar-get with linear polarization,the target is caught quickly and exactly,and the situation of the antenna is sta-ble.The tracking performences are satisfactory.
基金supported by the National Natural Science Foundation of China(Grant No.11972130)。
文摘This paper focuses upon the novel optical conical scanning imaging working mode design for small satellites.This kind of satellite employs only one inclined optical camera achieving wide-swath imaging via a rotational motion about the nadir axis either by the camera or by the satellite.Three working modes are designed,i.e.,high-speed rotational mode,low-speed rotational mode,and variable-speed rotational mode.For the high-speed and low-speed working modes,the camera rotates at a constant speed and the corresponding angular velocity is derived under the consideration of guaranteed coverage and minimized overlap.To improve the system performance,an enhanced working mode taking advantages of both the high-speed rotational mode and lowspeed rotational mode is proposed.Working in this variable-speed rotational mode,the camera rotates slowly to get high-quality pictures when it works,while it rotates rapidly to reduce the energy consumption and save the storage during which period the camera is turned off to minimize the overlap.All these working modes are illustrated in detail,and numerical simulation tests are conducted to validate their effectiveness.
