Top Read Articles

    Published in last 1 year |  In last 2 years |  In last 3 years |  All
    Please wait a minute...
    For Selected: Toggle Thumbnails
    Preliminary location accuracy assessments of GF-14 stereo mapping satellite without ground control points
    WANG Jianrong, YANG Yuanxi, HU Yan, LÜ Yuan, YANG Xiuce, LU Xueliang, CAO Bincai
    Acta Geodaetica et Cartographica Sinica    2023, 52 (1): 8-14.   DOI: 10.11947/j.AGCS.2023.20220255
    Abstract357)   HTML44)    PDF(pc) (10779KB)(320)       Save
    GF-14 is one of the highest mapping accuracy satellites in China, and is adopted advanced multi-load integrated for earth observation technology, which is mainly used for high accuracy location and mapping 1∶10 000 geographic information products on a global wide. In this paper, the payload, ground processing flow and its performance were briefly introduced, then the geometric performance of the satellite images was evaluated using different fields including domestic and foreign areas. As a result, the location accuracy without ground control points (GCPs) of single strip can reach 1.8 m in horizontal and 0.80 m in vertical elevation in domestic areas and 1.76 m in horizontal and 0.82 m in vertical elevation in foreign areas, which can reach the best known level in international optical photogrammetry on location accuracy without GCPs.
    Reference | Related Articles | Metrics
    Effect of satellite attitude quaternions on BeiDou precise point positioning during the eclipse season
    LIU Tianjun, CHEN Qusen, JIANG Weiping, CHEN Hua, XIA Fengyu, FAN Caoming
    Acta Geodaetica et Cartographica Sinica    2023, 52 (4): 550-558.   DOI: 10.11947/j.AGCS.2023.20220245
    Abstract187)   HTML21)    PDF(pc) (8413KB)(161)       Save
    In order to obtain high-precision positioning, precise point positioning (PPP) user side should keep the the consistent satellite attitude model with analysis centers. Based on the satellite attitude quaternions products provided by the Wuhan university analysis centers (WUM), we introduce the yaw angle computation method that uses satellite attitude quaternions. When the BDS-2/BDS-3 satellite is at a low sun elevation angle, the satellite attitude model strategy of WUM is analyzed. By using the open-source positioning software GAMP, the BDS-2/BDS-3 PPP solutions are also investigated with different satellite attitude strategies. During the deep eclipse season, the results demonstrate that the differences between nominal and quaternion yaw angles can reach 360°, which can cause the decimeter-level biases in the phase wind-up and antenna phase center offset correction. In this period, compared with the nominal attitude, the positioning accuracy of PPP solutions with satellite attitude quaternions can be improved approximately 32%, 29% and 38% in the earth (E), north (N) and up (U) components, respectively. Furthermore, the positioning accuracy of PPP solutions with satellite attitude quaternions can be improved approximately 29%,25% and 28%in the E, N and U components, respectively, when compared to that of the deleting the eclipsing satellite strategy(deleting satellite at the farthest and closest point of the orbit). The inconsistent attitude models would reduce the reliability of PPP positioning results, so the satellite attitude quaternions that provided from the analysis centers should be used for phase wind-up and antenna phase center offset correction in the PPP user side.
    Reference | Related Articles | Metrics
    Monitoring global coastline changes over 1987—2016 using Landsat data
    XU Nan
    Acta Geodaetica et Cartographica Sinica    2023, 52 (4): 691-691.   DOI: 10.11947/j.AGCS.2023.20210481
    Abstract126)   HTML13)    PDF(pc) (781KB)(101)       Save
    Related Articles | Metrics