Five-hundred-meter Aperture Spherical radio Telescope (FAST), will be the largest radio telescope in the world.
The dynamic surveying of the laser total station is one of the key technologies of FAST. So time-delay analysis for
dynamic surveying is very essential for the building of FAST. One Leica laser total stations are employed to measure
position of SMR. Laser tracker API is high-precision measuring device, and is used to monitor the spatial position of
SMR in the real time. Two kinds of measuring data were sent to the same measurement computer, so these data have the
same time-tag. Large numbers of experiment data were obtained, and there are many questions to be answered by this
experiment. The delay time was found, the dynamic measurement precision of laser total station was test. The results of
time-delay examination indicate that time-delay influence great the measurement and control precision. In spite of total
station's dissatisfactory aspects, e.g. time-delay, sample rate, the total station measurement system can meet the
requirement of the model. For higher precision, we need to take steps for eliminating time-delay. With the deepened of
study, the laser total station will play an increasingly important part in the FAST.
The metrology system to measure position and orientation of the cabin for FAST model consists of three Leica laser total stations. An innovative way was involved to test the performance of the metrology system. Large numbers of experiment data were obtained, including 116 groups of dynamic data and 62 groups of static data. There are many problems to be solved from experiment. 240ms delay time was found and characteristic frequency was detected. The dynamic capability of this metrology system was tested. The metrology system will work in the quasi static in FAST and FAST down scale model.The static position RMS error is less than 0.4mm and orientation RMS error less than 0.08°. Results of the total station examination indicate that this system can meet the requirement of the model. In spite of some dissatisfactory aspects, e.g. sampling rate, the total station will play an important role in the FAST.