Acta Geodaetica et Cartographica Sinica ›› 2026, Vol. 55 ›› Issue (8): 1482-1495.doi: 10.11947/j.AGCS.2026.20260159

• Cartography and Geographic Information • Previous Articles    

Fine structure extraction method of overpass based on trajectory and remote sensing image fusion

Yali Li1(), Yuezhu Hao1, Longgang Xiang2(), Caili Zhang3, Maohua Liu1   

  1. 1.School of Transportation and Surveying Engineering, Shenyang Jianzhu University, Shenyang 110000, China
    2.State Key Laboratory of Information Engineering in Surveying, Mapping and Remote Sensing, Wuhan University, Wuhan 430079, China
    3.School of Geomatics and Urban Spatial Information, Henan University of Urban Construction, Pingdingshan 467000, China
  • Received:2026-04-27 Revised:2026-06-17 Published:2026-09-09
  • Contact: Longgang Xiang E-mail:lyllhjgbx@163.com;geoxlg@whu.edu.cn
  • About author:Li Yali (1992—), female, PhD, lecturer, majors in multi-source spatio-temporal data fusion and analysis, and artificial intelligence. E-mail: lyllhjgbx@163.com
  • Supported by:
    Liaoning Provincial Department of Education Basic Research Project for Universities(LJ212410153040);Science and Technology Planning Project of the Liaoning Provincial Department of Housing and Urban-Rural Development(LNSJSKJ-2026-041);The National Natural Science Foundation of China(42471460)

Abstract:

Interchanges are critical components of urban grade-separated transportation networks, and the extraction of their fine-grained structures is essential for high-precision map construction and navigation route planning. Existing trajectory-based road network construction methods are susceptible to trajectory sparsity and projection overlap between upper-and lower-level roads, often resulting in road discontinuities and erroneous inter-level connections. Remote-sensing-image-based methods, constrained by two-dimensional orthographic projection and occlusion, have difficulty accurately representing the hierarchical topology of interchanges. To address these issues, this paper proposes a fine-grained interchange structure extraction method that integrates crowdsourced trajectories and remote sensing imagery. First, the crowdsourced trajectory data are preprocessed, and an initial road centerline is generated through density raster construction, skeleton extraction, and vectorization. The centerline is then sampled at equal intervals to construct initial geometric nodes. Next, to restore road network discontinuities caused by sparse trajectories, trajectory-derived geometric nodes are used as geometric priors and fused with candidate nodes extracted from remote sensing imagery to form a unified candidate node set. SAM-Road image features are subsequently employed to infer local connectivity and restore missing road connections. Finally, a topology correction method based on geometric continuity is developed to address pseudo-planar intersections in vertically overlapping areas. Pseudo-nodes are identified by evaluating pairs of oppositely directed extension vectors using cosine similarity, and the upper-and lower-level road networks are topologically decoupled through pseudo-node removal and path reconstruction. Experiments conducted using crowdsourced trajectories and remote sensing imagery from Beijing demonstrate that the proposed method effectively extracts fine-grained interchange structures. The geometric accuracy (GEO-F1 score) and topological correctness (TOPO-F1 score) reach 0.922 0 and 0.933 1, respectively, and the overall extraction performance surpasses that of the compared single-source methods.

Key words: overpass, crowdsourced trajectory data, remote sensing image, topological correction, road network construction

CLC Number: