Large-scale compact range on-site alignment based on laser tracker measurement network

Large-scale compact range generally consists of multi reflectors, how to align these numerous small reflectors into a high precision surface, this has to be carefully taken into account following two key issues: measurement system and alignment approach. Firstly, aim to solve the large scale, high precision and longtime stability measurement system issues, a measurement network based on laser tracker metrology was established, key technology for the metrology including: deducing the error in point measurement and uncertainty ellipsoid of laser tracker; optimizing the measuring stations and carrying out weighted measurement network regression. Secondly, a practical alignment approach was proposed; this approach divides the entire process into three key phases including: marked points positioning phase, gaps equalizing phase and constrained surfaces smoothing phase; due to gradually improve the adjustment precision step-by-step, it effectively reduces the adjustment iterations and avoids mutual physical contact, and ensure the surface accuracy and the gaps widths. Finally, the on-site alignment of a large compact range with a width of 23 m and height of 16 m which will generate a Φ15 m quiet zone at 40 Ghz is presented; The uncertainty of the measurement network is controlled to 0.025 mm, and the final surface root mean square accuracy was up to 0.054 mm and the gaps widths achieved 0.4 ± 0.2 mm.