光学与SAR卫星遥感影像复合式“立体”定位技术的研究

Research on Stereo Positioning among Optical & SAR Sensors

针对某些特殊区域因气候或污染造成立体成像测图的困难,尝试将光学与SAR卫星遥感影像联立构成"立体像对"进行复合式定位,并对其原理与方法进行研究与试验。以线阵CCD构像模型及F.Leberl公式为基础,利用若干地面控制点对线阵CCD影像和SAR影像分别进行外定向,再依据外定向参数将两种影像构成一"立体像对",从而建立复合式立体定位的数学模型,在已知一组同名像点的情况下,即可解算出相应地面点的大地坐标。初步试验表明,将具有一定重叠范围的多源卫星遥感影像构成"立体像对"进行复合式定位是可行的,且复合式立体定位可取得接近于传统立体像对的定位精度。

It is still difficult to acquire stereoscopic space-borne image pairs of some area for complicated climate condition or serious atmosphere pollution. This paper describes the geometric aspects and the mathematical treatment for the stereoscopic image pair composed of optical and SAR space-borne images in positioning. First, the geometric equation for linear array push-broom imagery and F. Lerbel model for SAR imagery as well as methods to simultaneously determine or refine individual parameters of these models are briefly reviewed. And a straight-forward singlestep procedure has been developed which follows the philosophy of photogrammetric bundle adjustment techniques. Then the composite stereoscopic pair is constructed according to these geometry models of optical and SAR images. The stereo positioning is the process of determining the ground coordinate of a ground point from a pair of corresponding homologous points in the composite stereoscopic pair. Experimental results show that it is feasible to construct stereoscopic pair with one optical and SAR image for composite stereo positioning, and its average positioning RMS value is close to stereoscopic pair with classical optical or SAR stereoscopic pairs.