CAJ | 학술논문

在被动定位中，从图像中提取目标的线性旋转不变特征很重要，而非合作目标特征提取要比合作目标困难得多。借鉴圆形目标固有的旋转不变特性，提出了一种虚拟圆方法。该虚拟圆为图像序列相邻帧内三个匹配点经等边三角形向外延拓生成的三个点的外接圆。模拟结果表明，此虚拟圆较其他途径构成的虚拟圆有尖锐的误差分布概率密度函数，进一步研究表明该虚拟圆的直径是一个相当不错的距离相关线段特征。线段特征用于距离估计的特点是简单，虚拟圆概念则增加了它在应用中的灵活性。因为三个匹配点是基于目标特征跟踪的最少匹配点数，故该方法在非合作目标被动定位中具有吸引力。该方法对相邻帧成像时目标相对相机偏斜变化不超过±10°有效。
재피동정위중，종도상중제취목표적선성선전불변특정흔중요，이비합작목표특정제취요비합작목표곤난득다。차감원형목표고유적선전불변특성，제출료일충허의원방법。해허의원위도상서렬상린정내삼개필배점경등변삼각형향외연탁생성적삼개점적외접원。모의결과표명，차허의원교기타도경구성적허의원유첨예적오차분포개솔밀도함수，진일보연구표명해허의원적직경시일개상당불착적거리상관선단특정。선단특정용우거리고계적특점시간단，허의원개념칙증가료타재응용중적령활성。인위삼개필배점시기우목표특정근종적최소필배점수，고해방법재비합작목표피동정위중구유흡인력。해방법대상린정성상시목표상대상궤편사변화불초과±10°유효。
It is critical to extract the linear rotational invariant of an imaged target in passive ranging from the images, and it′s more difficult to extract the parameters from a general non-cooperative than from a cooperative ones. A method was presented to construct a virtual circle as the inherent rotation invariance of a circular target. The proposed virtual circle was the circumcircle of equilateral by triangles extended from three matched points in adjacent frames in the image sequence. It is demonstrated by the simulations that the probability density function curve of the proposed virtual circle has tighter error distribution than that of a few other methods, and further studies indicate that the diameter of this virtual circle is also a preferable depth-related line segment feature. The line segment feature is used for the target distance estimation and it displays superior performance. It is characterized by its simple for the distance estimation using line segment features, and the concept of virtual circle increases the flexibility in practice. Because as few as three matched points are the least points in target tracking based image feature, so it is attractive for passive ranging to non-cooperative targets. The method is valid under the condition of the inclination angle of target relative to camera increased or decreased from -10 degree to 10 degree between adjacent sampling times.