When conducting coseismic slip distribution inversion with interferometric synthetic aperture radar (InSAR) data, there is no universal method to objectively determine the appropriate size of InSAR data. Currently, little is also known about the computing efficiency of variance component estimation implemented in the inversion. Therefore, we develop a variance component adaptive estimation algorithm to determine the optimal sampling number of InSAR data for the slip distribution inversion. We derived more concise variation formulae than conventional simplified formulae for the variance component estimation. Based on multiple sampling data sets with different sampling numbers, the proposed algorithm determines the optimal sampling number by the changing behaviors of variance component estimates themselves. In three simulation cases, four evaluation indicators at low levels corresponding to the obtained optimal sampling number validate the feasibility and effectiveness of the proposed algorithm. Compared with the conventional slip distribution inversion strategy with the standard downsampling algorithm, the simulation cases and practical applications of five earthquakes suggest that the developed algorithm is more flexible and robust to yield appropriate size of InSAR data, thus provide a reasonable estimate of slip distribution. Computation time analyses indicate that the computational advantage of variation formulae is dependent of the ratio of the number of data to the number of fault patches and can be effectively suitable for cases with the ratio smaller than five, facilitating the rapid estimation of coseismic slip distribution inversion.

在利用干涉合成孔径雷达（InSAR）数据进行同震滑移分布反演时，目前还没有通用的方法来客观地确定InSAR数据的合适大小。目前，对于反演中实现的方差分量估计的计算效率还知之甚少。因此，我们开发了一种方差分量自适应估计算法来确定滑移分布反演的InSAR数据的最佳采样数。我们导出了比传统的方差分量估计简化公式更简洁的变异公式。该算法基于不同采样数的多个采样数据集，通过方差分量估计本身的变化行为来确定最佳采样数。在3个仿真案例中，得到的最优采样数对应的4个低级别评价指标验证了该算法的可行性和有效性。与采用标准下采样算法的传统滑移分布反演策略相比，五次地震的模拟案例和实际应用表明，所开发的算法更加灵活和稳健，能够产生适当大小的InSAR数据，从而提供合理的滑移分布估计。计算时间分析表明，变分公式的计算优势取决于数据数量与断层斑块数量的比值，可以有效地适用于比值小于5的情况，有利于同震滑移分布反演的快速估计。