Comparing with the image-based method, the method based on fan beam projections have better real-time and lower detecting cost due to its needlessness of image reconstruction.

• 相比于基于图像重建的方法，本文提出的方法不需要进行图像重建，因此具有更好的实时监控性和更低的监控成本，具有一定的现实意义。