2 results about "Dynamic aperture" patented technology

The application discloses an ultrasonic CT waveform inversion method and device based on a dynamic aperture, and belongs to the technical field of ultrasonic image processing, and comprises the following steps: acquiring an observed sound pressure signal at a position of a receiving element of an ultrasonic CT data acquisition system; inputting a current sound velocity distribution into a wave equation to obtain a synthesized sound pressure signal at the position of the receiving element; for each transmitting element, extracting the synthesized sound pressure signals at the positions of M receiving elements away from the transmitting element; calculating the difference between the synthesized sound pressure signals at the positions of the M receiving elements corresponding to all the transmitting elements and the corresponding observed sound pressure signals; calculating the gradient of the current sound velocity distribution by using an adjoint state method according to the difference, and then obtaining an updated sound velocity distribution; re-substituting the updated sound velocity distribution into the wave equation for iteration, and simultaneously increasing the value of M until the iteration is stopped, and outputting the updated sound velocity distribution. The application can improve the accuracy of a reconstructed image under the condition of missing low-frequency information.

According to the FSO system visual feedback alignment device based on multi-optical-axis rigid integration, the independent optical axis design is adopted, no spectroscope is arranged in a signal receiving main link, zero-loss receiving of light energy is achieved, the sensitivity of a communication system is remarkably improved, the communication distance of the communication system is remarkably increased, and energy efficiency maximization is achieved. In order to solve the parallax problem caused by an independent optical axis, a dynamic aiming circle is designed, and zoom self-adaptive'dynamic aperture 'aiming can be achieved. The upper computer calculates and draws a circle representing an optimal power point in real time according to the current camera magnification, and a user does not need to care about a specific angle value and only needs to move a beacon light spot into the circle, so that accurate alignment can be realized. A zoom camera structure is adopted, the contradiction that a single focal length cannot give consideration to near-field wide-angle search and far-field long-focus identification is solved, a target can be seen clearly through zoom under different communication distances, and the alignment precision is ensured through an algorithm.