48 results about "Coherent processing interval" patented technology

The invention relates to a knowledge-assisted broadband radar target detector in non-uniform clutter and a design method, and the method comprises the steps: dividing a broadband radar target signal into a plurality of sub-bands, and obtaining each sub-band and each pulse signal during a coherent processing interval; the method comprises the following steps: dividing a broadband radar non-uniform clutter signal into a plurality of sub-bands, modeling a clutter covariance matrix into a random matrix, and obtaining clutters of auxiliary data in each sub-band; obtaining a probability density function of clutters of the auxiliary data in each sub-band, and establishing a clutter covariance matrix relation model and a clutter power relation model between the original data and the auxiliary data; establishing a broadband radar target detection problem model according to each pulse signal and the clutter of the auxiliary data; and constructing a knowledge auxiliary detector by using a maximum posterior probability density function. According to the method, a knowledge auxiliary detector for broadband radar target detection in the non-uniform clutter environment is provided, and the problem of broadband radar target detection in the non-uniform clutter environment is solved.

The invention discloses a method for space-time adaptive processing of airborne radar based on EFA (Extended Factored Approach) and MWF (Multistage Wiener Filter). The train of thoughts is that the method comprises the following steps: performing spatial domain dimension reduction processing on echoes received by the airborne radar in a coherent processing interval; acquiring included N sub arrays of the airborne radar in a coherent processing interval after spatial domain dimension reduction; recording the echo received by the nth sub array of the airborne radar in a coherent processing interval after spatial domain dimension reduction as Xn; then calculating an echo space-time vector Yk of the kth Doppler channel in the N sub arrays of the airborne radar after weighted fast Fourier transform processing; then performing multistage wiener filtering processing on the echo space-time vector Yk to obtain an echo adaptive weight vector W[Yk] of the kth Doppler channel in the N sub arrays of the airborne radar after D-stage wiener filtering processing; and finally, performing wiener filtering on the echo space-time vector Yk by using the echo adaptive weight vector W[Yk] to obtain an echo adaptive weight vector Zk of the kth Doppler channel in the N sub arrays of the airborne radar after two-stage dimension reduction space-time adaptive processing based on the EFA and the MWF.

A radar antenna system includes a single transmitter for creating pulses from a wideband waveform. A splitter divides each pulse into half-power pulses, and sends them along respective paths. On one path, successive half-power pulses are alternately modulated with a phase shift ϕA or ϕF. On the other path, the half-power pulses are not modulated. Each modulated half-power pulse is then combined with an un-modulated half-power pulse to transmit pulses of a full aperture beam with either ϕA or ϕF. This establishes two degrees of freedom for the system. Two separate receivers then simultaneously receive the pulse echoes and a signal processor uses the consequent four degrees of freedom to create a radar indicator with mitigated clutter and useable azimuth estimation. A coherent processing interval can then be selected for multi-mode operation of the system.

The invention provides an airborne radar real-time Doppler beam sharpening super-resolution imaging method, which belongs to the field of radar detection and imaging. The present invention adopts the fast iterative weighted least squares estimation to realize Doppler beam sharpening (DBS) super-resolution imaging for the echo signal of the current adjacent coherent processing interval (CPI) by means of scanning-while-acquiring-while-processing , and then use the spatial correlation of adjacent CPI azimuth echoes to recursively update the next CPI weighted least squares estimation result, thereby improving the convergence speed and greatly reducing the computational complexity. Compared with the traditional DBS imaging technology, the present invention can not only effectively improve the imaging resolution, but also can reduce the number of iterations, improve the convergence speed, and satisfy the real-time imaging performance while ensuring the imaging resolution.