一种高精度超大仪器高的测量方案设计

针对中国散裂中子源（CSNS）隧道内装置区永久点采用常规GPS三脚架观测模式中对中整平和仪器高量取精度差等问题，提出了一种高精度的仪器对中和超大仪器高的测量方案。该方案设计可微调的屋顶支架、目标半球垂准镜，实现了仪器的稳固安置和精确对中；改造GPS天线头支架适于放置目标球，以便采用激光跟踪仪获取高精度的超大仪器高；最后通过激光跟踪仪对隧道内6个装置区永久点重复两次测量，并与钢尺测量结果进行比较。结果表明，该方案可实现高30 m内仪器0.5 mm的对中精度和0.2 mm的量高精度，避免了卷尺测量尺长受拉伸影响的缺点，有效解决了CSNS装置永久点的精密对中和超大仪器高的获取，也为同类点位的对中和仪器高测量提供了借鉴和参考。

A High Precision Measurement Design to Obtain Super Instrument Height

Since the accuracy of centering leveling and instrument height measurement is poor when the permanent point of device area in tunnel of the Chinese spallation neutron source ( CSNS) being observing in the conventional GPS tripod observation mode, a high precision measurement scheme is proposed. In the scheme, the fine-tuned roof bracket and the hemisphere plumbing mirror are designed to ensure stable placement and precise alignment. GPS antenna head bracket is modified to be suitable for placing the target ball and use laser tracker to obtain high precision large instrument height. Finally, six permanent points are measured twice individually using laser tracker which result is compared with the measurement result using the ruler. The results show that the scheme can achieve a high accuracy of 0. 5 mm in centering and 0. 2 mm in height measuring, which avoids the influence of stretching using ruler to measure, and effectively improve the precision of centering and large instrument height measurement of the permanent point of device area of the CSNS. In addition, the new scheme also provides reference for centering and instrument height measurement of similar points.