BDS建立超高层建筑施工控制网的约束平差分析

Analysis of constrained adjustment for establishing construction control network of super high-rise buildings using BDS

针对评估北斗卫星导航系统(BDS)独立建立超高层建筑施工控制网的可行性,分析不同约束条件对网平差的影响,该文结合建立超高层建筑施工控制网工程实例,比较了BDS和全球定位系统(GPS)静态控制测量的精度差异,研究了高精度全站仪距离测量作为约束条件对网平差的影响。实验结果表明,BDS独立建立超高层建筑施工控制网完全可行,BDS静态控制网坐标约束平差后整体点位精度相对于GPS平均高出15.7%;进一步将全站仪测距值作为约束条件进行网平差后,相对于坐标约束平差,使用GPS观测值的网平差结果在施工坐标系两个方向上分别平均改善了10.3%和29%,BDS分别平均改善了16.7%和18.9%,GPS+BDS组合则分别平均改善了11%和24.7%,同时还将网平差的尺度差平均减少了65.9%,使基线向量平差后的尺度与地面网的尺度更加接近。

In order to evaluate the feasibility of establishing the construction control network for super high-rise buildings using Beidou satellite navigation system(BDS) independently and analyze the influence of different constraints on network adjustment,the accuracy difference between BDS and global positioning system(GPS) static control survey were compared with the construction control network survey case of a super high-rise building in this paper,also the influence of high-precision total station distance measurements as a constraint for network adjustment were analyzed.The results showed that it was completely feasible to establish the construction control network of super high-rise buildings using BDS.The overall point accuracy after adjustment with constrained coordinates was 15.7% higher than that of GPS on average;after the network adjustment was further carried out with constrained distance measured by total station,compared with the adjustment with constrained coordinates,the network adjustment results of the GPS observation values were improved by 10.3% and 29% respectively in the two directions of the construction coordinate system,the BDS was improved by 16.7% and 18.9% respectively,and the GPS+BDS combination was improved by 11% and 24.7% respectively,moreover,the scale difference of the network adjustment was reduced by 65.9% on average,so that the scale of the baseline was closer to that of the ground network.