Teng Long

SPECAN algorithm for forward-looking bistatic SAR

In this paper, we present a computationally efficient method for forming image from FL-BSAR phase history data. First, the bistatic geometry and an ideal signal model that results from it were defined. Then, based on this ideal signal model, image formation was deduced and the flow-chart of algorithm was given out, finally, we analyzed the limits on the scene size. The validity of the SPECAN algorithm is proved by the imaging results.

A long-term coherent integration method of phase-coded pulse train

In pulsed Doppler radar, the phase-coded signal is used to achieve high range resolution profiles. When the target radial velocity is high, linear range migration occurs. It results in the degradation of a long-term coherent integration. A novel coherent integration method of coherent phase-coded pulse train is proposed based on Keystone transform. In order to reduce the computation complexity, the FT-IFT (Fourier transform - inverse Fourier transform) algorithm is presented for the implementation of Keystone transform. By using the proposed method, the detection sensitivity of weak targets is improved. Some computer simulation results are presented which illustrate the effectivity of the method.

Design and realization of high-performance universal radar signal processing system

Designing high-performance universal radar processing system is the method of solving the problem of increasing task needs of new radar system and that of different arithmetic requiring different system structure. Based on the theoretical analysis on the shared bus type and distributed type parallel structure, and according the characteristic of the radar signal processing, one high-performance universal radar signal processing system was designed and realized. The system has the characteristics of standardization, modularization, scalability, restructure, hybrid parallel processing, and multi-layer interconnection. And through using the system to design and realize typical radar signal processing system, the high-performance and the universality of the system were proved.

The Fourier analyse of Non-truncation DDS output characteristic

Using the principle of number theory, periodicity property of the output phase sequences of an M-bit Non-truncation DDS phase-accumulator have been analyzed, and the linear relationships between them have been deduced as well. Combining the symmetry property of the Discrete Fourier Transform Matrix, linear relationships between spectrums of different output signals generated by different frequency control words with the same Lowest Nonzero Bit Position have been deduced. The analysis results show that the output signals can be grouped into M groups, according to the lowest nonzero bit position of their frequency control words. Signals in the same group have the identical Signal-to-Noise-Ratio(SNR) and Spurious Free Dynamic Range(SFDR). As a result, only M DFTs are necessary for the analysis of all output signals generated by an M-bit Non-truncation DDS. Simulation results showed that the academic analysis is correct.

Critical address aligning issues in real time DSP image processing system

This paper focuses on the critical address aligning issues in real time DSP image processing system. SAD and byte array moving operation which are quite sensitive to the address aligning issues are discussed thoroughly, and get well solved. At the end of the paper, we present an optimized design and implementation of the template matching real time image processing system based on the high performance TigerSHARC DSP COTS module and the solution of severe address aligning issues.

Maneuvering target tracking based on multistatic system Doppler measurements

The bistatic Doppler measurements are introduced to multistatic target tracking. A complete velocity vector may be deduced by more than two Doppler measurements, which may be more accurate than other measurements in a multistatic system. A sequential velocity vector method in maneuvering interactive multimode method (IMM) filtering and data fusion is introduced in this paper. These Doppler measurements are considered to come from another sensor, and the farther data processing of this sensor produces the velocity measurements. Monte Carlo simulation is introduced to compare its performance with the traditional one. The result demonstrates that it has better performance in maneuvering target tracking, and has a nice association quality under smaller calculation capacity than JPDA.

A high-speed real-time digital signal processor for the modulated frequency stepped pulse radar signal

The modulated frequency stepped pulse radar signal uses a chirp signal as the in-burst pulse of a frequency stepped pulse string radar signal, so it has the advantages of both chirp pulse and frequency stepped burst. The signal processing algorithms should firstly do chirp pulse compression, then do IFFT to acquire the high range resolution. This paper analyzes the algorithms of this kind of radar signal processing, implements the signal processor on the most powerful DSP chip TMS320C6201, analyzes the finite word length effect caused by the TMS320C6201, and offers the solution to this effect.

Research on Applications of Chaff

Through the analysis of the mechanism and motion characteristics of chaff, mathematic models are built for threaten target and chaff. To support strategy making, the applications of chaff are studied in various environments, with aspects of chaffs usage methods, timing of jamming, strength of jamming etc

A digital signal processor for high range resolution tracking radar

This paper studies the processing of the modulated frequency stepped radar signal, which is a kind of high range resolution radar signal. The influence of the targets velocity and its solution are introduced firstly, and a high-resolution range tracking and angular tracking algorithm are advanced. The radar digital signal processor uses many TMS320C6201 DSP chips, and the processing flow of the DSP is given. The paper finally offers the experimental results, and the results prove the correctness of the theoretical analysis.

Improved High Range Resolution Profiling using synthetic spectrum processing and stepped-frequency LFM waveforms

In this paper, an improved synthetic spectrum signal processing schemes using stepped-frequency waveforms is presented which enables High Range Resolution Profiles (HRRP) of targets. This synthetic spectrum schemes contrasted with conventional or hybrid stepped-frequency methods achieves both unambiguous range coverage as well as good range grating lobes without requiring a large number of frequency steps. We present the reason why the grating lobes are located and why the ambiguous ranges are occurred by analyzed the ambiguity function, autocorrelation function and parameter setting of such signal. Because this method need more data memory and computation resource, we studied the factors which effected the performance of high range resolution profiling, such as waveform, processing parameter and system delay, and give a realized application for real time system.