近程毫米波合成孔径辐射计被动测距原理

Near range millimeter wave synthetic aperture radiometer passive range measurement

毫米波合成孔径技术利用了物体自身辐射电磁波的相位信息,采用很少阵元就能实现实时成像,但目前合成孔径技术只是限于亮温成像,缺少了目标的距离信息,这对于目标探测与识别很不利。提出在近程条件下合成孔径被动测距原理和相应的双正交傅立叶变换算法,并给出了近程距离分辨率公式,近程成像的特点是成像公式中存在二次相位因子,而且距离分辨率和距离的平方成反比。毫米波合成孔径被动成像可以同时得到物体辐射的亮温分布和距离分布,能够有效克服离焦引起的图像模糊,对图像的反降晰和目标识别具有重要意义。

Millimeter wave synthetic aperture radiometer（MMW-SAR） technology will be real-time imaging with less receiver elements due to use phase information of electromagnetic wave radiating from target.But MMW-SAR is limited to brightness temperature imaging nowadays,it is very unfavorable for target detection and identification lacking of target range information,thus this paper presents novel principle and BFT algorithm for MMW-SAR passive range measurement under near range conditions,and then gives the range resolution formula.The features of near rang imaging are existence of quadratic phase factor in imaging formula and the range resolution is inverse proportion into the square of range.MMW-SAR passive imaging can get both range distribution and brightness temperature distribution,which could effectively overcome fuzzy problem caused by defocus.