Laser detecting technology can be utilized to the product surface detection for finding the surface deficiency. However, the improving resolving power of laser detecting system is limited by the laser footprint size on the product surface. Employing only echo delay and intensity information, the information of the surface inside the footprint is difficult to be obtained for the echo signal of the objects maybe is submerged by each other. Under the remote laser detecting, the serious loss of image quality may occur because of the large footprint. The product surface detection method based on the single laser return waveform was studied and the provided to get the objects information inside the laser footprint. Firstly, the basis laser echo signal model of the objects inside the footprint was built. On the basis, the decomposition algorithm was provided which can decompose a laser return waveform into a series of components assuming that each component corresponding to a sub-object inside the laser footprint. After the primary sub-target return waveforms was obtained, however, there still exists some small sub-objects inside the laser footprint whose return signal is hardly to be extracted because they are submerged by the neighborhood sub-objects return signal. The subtracting algorithm between the whole return waveform and the components waveform provides the way to get the submerged return waveforms of sub-target. So, the information of sub-objects inside the laser footprint would be obtained. In the end, the actual laser return data of the product surface was analyzed employing the method to get the range position information of the sub-objects inside the laser footprint, which verifies the method validity.
A Water Surface Detection Method by Correlation Analysis of Watermark Images with Time Interval
