3 results about "Time gating" patented technology

This invention discloses a method for generating and evaluating Doppler simulation data for low-Earth orbit (LEO) satellites. By employing source-end discrete-time gating, the system is forced to directly block output when the time deviation exceeds 1 ms, fundamentally severing the error coupling path and ensuring the purity of the output data. In the inertial frame velocity synthesis, an explicit Earth rotation-related velocity correction term is introduced, enabling even stationary receivers to accurately reflect their motion in inertial space. An elevation-angle-weighted noise model is used to accurately simulate the physical phenomenon of sharp link deterioration in LEO satellites at low elevation angles, realistically reflecting the tracking and loss-of-lock behavior of receivers in complex geometric environments. Terminal physical consistency verification is introduced. By comparing the distance change rate calculated in the velocity domain with the distance rate of the position domain derivative in real time, a rigorous closed-loop feedback mechanism is constructed, which can automatically identify and eliminate abnormal data caused by ephemeris jumps or numerical divergences, significantly improving the engineering confidence of the simulation data.

The application provides a heterodyne distributed acoustic wave sensing system based on frequency shift time gating and a demodulation algorithm, and belongs to the technical field of distributed acoustic wave sensing. A light coupling module divides continuous laser into two paths of signal light and local oscillator light. A light modulation module sequentially performs pulse modulation and frequency shift modulation on the signal light, and outputs the modulated light pulse. A sensing optical fiber receives the light pulse output by the light modulation module, and generates a backscattering signal based on the back Rayleigh scattering effect. A light mixing module coherently mixes the backscattering signal and the local oscillator light. A photoelectric detection module converts the coherently mixed light signal into an electric signal. A signal processing unit collects the electric signal and extracts vibration information at different positions of the optical fiber through a phase demodulation algorithm. The application realizes synchronous integration of pulse and frequency shift modulation, optimizes the demodulation algorithm, improves the system stability, sensing accuracy and response efficiency, reduces the hardware cost and energy consumption, and is suitable for multi-scene application through innovative light path design and signal processing strategy.

This invention discloses a method and system for early warning of abnormal behavior of dormitory personnel based on millimeter-wave radar. It combines three-dimensional spatial semantic modeling to divide the area into beds, desktops, and floors, and introduces a time gating mechanism to filter normal sleep and accurately determine abnormal prolonged lying-down states. By extracting the trajectory curvature probability distribution entropy value and round-trip repetition degree within specific semantic regions, it effectively overcomes the limitations of existing technologies in objectively quantifying and accurately identifying latent behavioral patterns such as student anxiety in real-life scenarios. A multi-source evidence fusion framework is constructed, which dynamically weights radar motion intensity evidence and acoustic energy evidence by calculating the spatial consistency between the radar target and the audio source location. Furthermore, by utilizing synthesis rules that include conflict handling, it effectively suppresses false alarms, greatly improving the accuracy and reliability of fall detection and violent conflict identification in complex practical applications.