(1. 中南大學(xué) 地球科學(xué)與信息物理學(xué)院，長(zhǎng)沙 410083；2. 中南大學(xué) 物理與電子學(xué)院，長(zhǎng)沙 410083)
摘 要: 基于連續(xù)波信號(hào)的穿墻雷達(dá)定位系統(tǒng)憑借其低廉的成本、簡(jiǎn)潔的結(jié)構(gòu)以及優(yōu)秀的靜態(tài)雜波抑制等諸多優(yōu)勢(shì)，無(wú)論是在軍事還是民用領(lǐng)域都受到廣泛關(guān)注。然而，連續(xù)波穿墻雷達(dá)的傳統(tǒng)定位算法基于短時(shí)傅里葉分析，由于受限于算法所固有的時(shí)頻分辨率折中矛盾，其探測(cè)精度通常較差。針對(duì)傳統(tǒng)定位算法在時(shí)變低信噪比條件下檢測(cè)精度低、虛警率高以及目標(biāo)識(shí)別困難等缺陷，提出一種基于高階模糊函數(shù)的目標(biāo)定位新算法。該算法通過實(shí)時(shí)估測(cè)噪聲的統(tǒng)計(jì)參數(shù)，自適應(yīng)地對(duì)濾波器函數(shù)進(jìn)行調(diào)整，實(shí)現(xiàn)在時(shí)變低信噪比條件下的恒虛警檢測(cè)，抑制虛假目標(biāo)的產(chǎn)生；此外，該算法還能基于回波的高階模糊函數(shù)對(duì)多個(gè)目標(biāo)分量進(jìn)行高精度分離和參數(shù)估計(jì)，同時(shí)實(shí)現(xiàn)對(duì)多個(gè)目標(biāo)的準(zhǔn)確跟蹤和定位。實(shí)驗(yàn)結(jié)果驗(yàn)證了新算法的有效性，證實(shí)其能夠提供比傳統(tǒng)算法更高的檢測(cè)精度，為連續(xù)波穿墻雷達(dá)的高精度成像提供可能。
關(guān)鍵字: 連續(xù)波穿墻雷達(dá)；恒虛警檢測(cè)；高階模糊函數(shù)；CLEAN 算法
（1. School of Geosciences and Info-Physics, Central South University, Changsha 410083, China;
2. School of Physics and Electronics, Central South University, Changsha 410083, China）
Abstract:In both the military and civil areas, through wall radar based on continuous wave signals was attached people’s attentions because of its obvious advantages, such as low price, compact structure and outstanding ability of static clutter suppression. However, the corresponding detection accuracy of the traditional target localization algorithm, which is based on the short time Fourier transform (STFT), is usually poor because of the inherent tradeoff of the algorithm between time and frequency resolutions. A new target localization algorithm, which is based on the high order ambiguous function, is proposed to deal with the issues such as low detection accuracy, high false alarm rate and identification difficulties in time-varying low signal-to-noise ratio environments. The proposed algorithm can estimate the noise statistic coefficients in real time and adapt the filter function accordingly to maintain a constant false alarm rate and suppress the rise of the fake targets. Besides, this algorithm can achieve high accurate separation and parameter estimation to multiple signal components based on the high order ambiguous function of the echo, which can help observers accurately track and locate multiple targets. The experimental results verify the effectiveness of the new algorithm that larger detection accuracy can be afforded than the case when the traditional algorithm is used individually. The possibility for the high resolution imaging of the continuous-wave through-wall radar can be obtained with the new algorithm.
Key words: through wall radar; constant fake alarm rate; high order ambiguous function; CLEAN algorithm
