46results about How to "Improve measurement signal-to-noise ratio" patented technology

The invention discloses an on-line digestion and detection device for total nitrogen content in a solution, which comprises a light source, a digestion device, a reflex condenser, a sampling detection mechanism, and a light guide stick, wherein a top end of the digestion device is connected with the reflex condenser; the outer surface of the digestion device is provided with a heating device; thelight guide stick is inserted into the digestion device and the reflex condenser; the upper end of the light guide stick corresponds to a detection disk of the sampling detection mechanism, and the lower end of the light guide stick corresponds to the light source. The invention is the on-line digestion and detection device for the total nitrogen content in the solution which has a simple and compact structure, low cost, simple and convenient operation, high measurement accuracy, and quick measurement speed.

The invention discloses a brain-computer interface system based on an atom magnetometer, and a use method thereof. The invention combines the work characteristics of the atom magnetometer to design abrain magnetic cap and a magnetic shielding device with practicality; a scheme of separating an atom magnetometer probe from a light source is adopted to improve a system integration level; system probability is intensified; a brain magnetic signal processing process capable of greatly improving operation speed and reducing processing process complexity; and for scenes which may be applied by thesystem, a feasible commutation and peripheral support system is given. By use of the brain-computer interface system provided by the invention, the control of a local and remote application system isfinished conveniently through the brain magnetic signal, and the system owns practicality and good expansion performance.

The invention discloses an adaptive optical system based on a modulation and modulation-free combined pyramid wave-front sensor. The adaptive optical system comprises a wave-front correction module, a beam-splitting module, an imaging module, a pyramid wave-front sensor module and a control module, wherein before the adaptive optical system works, the pyramid wave-front sensor in a modulation operating mode is utilized to measure the transfer function of the system, and when the adaptive optical system works, the pyramid wave-front sensor in a modulation-free operating mode is utilized to perform closed-loop control. According to the adaptive optical system, the signal to noise ratio can be improved when the transfer function of the system is measured, and a stable transfer function matrix is obtained; and meanwhile, the detection sensitivity can be effectively improved in the closed-loop control process.

The invention relates to a differential anti-jamming current amplifying circuit with two channels, wherein a first and a second input ends of an electric current-voltage convertor are used as a first and a second input ends of the invention, and reference voltage ends of the first and the second input ends are used as a first and a second reference input ends, the output ends of the first and the second electric current-voltage convertors are respectively connected with positive input ends of a first and a second differential amplifiers, the first and the second reference input ends are respectively connected with negative input ends of the first and the second differential amplifiers, the output ends of the first and the second differential amplifiers are respectively connected with a positive-negative input end or a negative-positive input end of a secondary differential amplifier, and the output end of the secondary differential amplifier is the output end of the invention. The invention successfully measures weak signal of pien grade under the condition without a screen, measuring signal-to-noise ratio can be further improved under the condition with the screen, and non-electric common mode interference signal of vibration, thermal drift and the like can be inhibited.

A multicarrier non-linear clipping distortion compressed sensing estimation method of relieving the observation interference, provided by the present invention, comprises the following steps of S1 before the target information is measured, pre-configuring a channel observation interference inhibition module; S2 before the target information is measured, using the channel observation interference inhibition module to pre-estimate an observation interference component, denoising a reception end original frequency domain symbol, and constructing an alternative observation vector; S3 during a target information measurement process, generating a corresponding row step measurement matrix according to the observation interference component estimation information, a measurement compression ratio and a measurement criterion, and acquiring data in a plurality of sub-channels as the final observation vector information. The method of the present invention still shows a strong communication performance on the conditions of the low measurement compression ratio and the depth clipping, and enables the system robustness to be improved.

The invention provides a self-adaptive high-dynamic-range three-dimensional measuring method based on a gray scale histogram. The method comprises: through analyzing the gray scale histogram of a measured object, determining the reflectivity distribution of the measured object and the optimum exposure time needed by each reflectivity; and using an exposure technology for multiple times, respectively exposing the measured object according to the optimum exposure time needed by each reflectivity, obtaining images of the measured object, shot in the different optimum exposure time, and then fusing the images shot in the different optimum exposure time so as to restore the three-dimensional morphology of the measured object. The method overcomes the blindness existing in a conventional high-dynamic-range measuring method and improves the measuring efficiency.

The invention discloses a DOAS measurement system by means of polarizing beam splitting. The DOAS measurement system comprises a lambda / 4 wave wafer, a polarizing beam splitting piece, a parabolic mirror primary mirror, a corner mirror, an optical fiber, a power source device and a spectrograph detector. By means of the characteristics of the polarizing beam splitting piece, due to the fact that a signal carrying an absorbing spectrum passes through the lambda / 4 wave wafer for two times, the polarizing state will change, and the signal will be reflected to the receiving optical fiber by the polarizing beam splitting piece; due to the fact that a telescope stray light signal which does not carry the absorbing spectrum and is not in atmospheric transmission does not pass through the lambda / 4 wave wafer, the polarizing state does not change, and the signal passes through the polarizing beam splitting piece and will not be reflected to the receiving optical fiber by the polarizing beam splitting piece. Compared with an existing light-path receiving and transmitting integrated DOAS measurement system, the DOAS measurement system can reduce the proportion of stray light inside a telescope and scattered light in the atmospheric background in the measurement signals, also improve the signal to noise ratio of DOAS measurement on the premise that the lighting effect is ensured, and improve the detection precision of the DOAS.