干涉参数定标对于机载双天线InSAR（Interferometric Synthetic Aperture Radar）系统的大面积高精度数字高程模型（DEM，Digital Elevation Model）获取具有重要意义。为了高效地进行干涉参数定标，本文从双天线InSAR获取DEM的基本原理出发，构建了一种新的考虑干涉相位偏置、基线长度和基线水平角三个干涉参数的外定标模型，设计了外定标模型的未知参数解算方案。利用GPS（Global Position System，全球定位系统）实测的高程控制点对中国科学院电子学研究所自主研制的机载双天线InSAR系统进行了干涉参数定标实验，统计了利用定标后干涉参数反演地面高程的精度，验证了所采用外定标模型及解算方案的正确性和有效性。-It is significant to calibrate interferometric parameters of dual-antenna airborne InSAR（Interferometric Synthetic Aperture Radar）systems for deriving accurate DEM (Digital Elevation Model) with large areas. A new outside calibration model considering phase offset, baseline length and baseline angle was proposed in order to calibrate interferometric parameters effectively, which was induced from the basic theory of DEM deriving from InSAR. And its solution scheme was designed. The outside calibration experiments were done with height control points measured by GPS to calibrate the dual-antenna airborne InSAR system researched independently by Institute of Electronics, Chinese Academy of Sciences. The accuracy of heights derived with calibrated interferometric parameters was calculated, as validated the proposed calibration model and its solution algorithm.