A Fast PS Sequence Selection Algorithm for GNSS-Based InBSAR

Global Navigation Satellite System-based bistatic synthetic aperture radar interferometry (GNSS-based InBSAR) enables near-real-time 3D deformation monitoring by combining interferometric phases from different satellites at varying time points. However, the low resolution and low SNR compromise the reliability of PS association in time-series imagery, introducing the reuse of PSs. To achieve this, it demands PS selection algorithms with both high computational efficiency and precision. In this letter, a fast PS sequence selection algorithm is proposed for GNSS-based InBSAR. First, pre PS sequences are screened based on sequence length, SNR, position offset, and amplitude dispersion to ensure interferometric phase stability under low-SNR conditions. Second, a criterion is set to select the ’best’ sequence, facilitating the rapid removal of duplicate PSs. Finally, the computational load is quantitatively characterized, demonstratingO(n2)efficiency. Validation of the proposed algorithm is carried out by using BeiDou satellite measured data, achieving 2-hour-interval 3D deformation measurements.