With the continuous increase of global greenhouse gas concentrations and the escalating issue of climate warming, lidar based on the differential absorption coherent detection principle has become crucial for vertical profiles of greenhouse gas concentrations. To address the technical challenges in current ground-based CO₂ detection lidar systems of simultaneously achieving high integration, high precision, high range resolution, and long-term stability, this study developed a micro-pulse CO₂ profiling lidar operating at 1.57 μm with an all-fiber-integrated architecture. The system combines an injection-locked fiber laser and an off-axis reflective telescope in a coaxial transceiver design, realizing a compact system architecture(0.93 m × 0.34 m × 0.34 m) and sub-picometer wavelength stability (<0.6 pm under 10°C~40°C thermal variations). Horizontal detection experiments as well as continuous observation experiments were conducted. Experiments for horizontal detection revealed a significant linear relationship (R²=0.998) between the logarithmic ratio of dual-wavelength echo power and the detection range, confirming system precision; and the stability of the lidar system was verified by a continuous observation experiment.

To address the prevalent issues of poor hardware platform versatility and high redundancy development in China's arrow-borne telemetry transmitters, this paper proposes a novel universal design methodology based on operational requirements analysis of existing equipment. By constructing a dynamic reconfigurable intelligent software architecture, diverse mission requirements across different models can be achieved on a universal hardware platform. When mission parameters change, hardware circuit redesign is eliminated; instead, functional updates and parameter adjustments are accomplished via external serial communication with a ground station. Compared to conventional dynamic reconfiguration techniques that only support static parameter modification, this architecture enables real-time online updates and software reconfiguration of telemetry transmitters. Leveraging a crewed spaceflight mission as an engineering case, a multi-code rate arrow-borne telemetry transmitter is developed, with key technologies including universal hardware platform design, real-time health monitoring, and dynamic reconfigurable software architecture thoroughly investigated. Experimental results demonstrate that the proposed solution achieves high integration, autonomous control of domestically produced chips, and real-time health monitoring accuracy. Successful maiden flight validation confirms its engineering feasibility, providing an innovative technical pathway for next-generation arrow-borne telemetry systems.

In response to the high reliability requirements of missile-borne equipment in complex mechanical environments, a design method for vibration isolators based on high-manganese copper alloy is proposed. Firstly, a dynamic model of the missile-borne equipment was established, and the damping characteristics of the high-manganese copper alloy were thoroughly analyzed to determine its damping parameters. Subsequently, to balance the damping and strength properties of the vibration isolator, an optimization design model for the missile-borne equipment vibration isolator based on high-manganese copper alloy was constructed. The genetic algorithm was employed to optimize the relevant design parameters of the vibration isolator, resulting in an improved design scheme. Finite element analysis and mechanical testing demonstrates that, compared to traditional silicone rubber vibration isolators, the deformation of the high-manganese copper alloy-based vibration isolator was reduced by 40%, while its damping characteristics still met the vibration isolation requirements of the missile-borne equipment. This fully proves the superiority and rationality of the proposed design scheme.

Spaceborne synthetic aperture radar is one of the important means of detecting ocean internal waves, and sea surface wind speed has a significant impact on the ability of synthetic aperture radar to detect ocean internal waves. Based on the theory of the influence of sea surface wind speed on the ability of synthetic aperture radar to detect ocean internal waves, combining the insitu measured parameters of ocean internal waves, additional with the corresponding ocean environment and synthetic aperture radar data, this paper analyzes the imaging mechanism of ocean internal waves on synthetic aperture radar images, discusses the different manifestations of upward and downward ocean internal waves, and elaborates on the ability of synthetic aperture radar to detect ocean internal waves under the combined influence of internal wave amplitude, thermocline depth, and thermocline intensity under different wind speed conditions. Simulation analysis shows that the smaller the sea surface wind speed, the larger the internal wave amplitude, the shallower the thermocline depth, and the stronger the thermocline intensity, the stronger the ability of synthetic aperture radar to detect internal waves in the ocean. The results can provide technical support for the planning of satellite observation tasks in the early stage of detecting ocean internal waves using spaceborne synthetic aperture radar.

The current wireless SAW (Surface Acoustic Wave) sensor based on langasite (LGS) can work at temperatures as high as 600 °C. Nevertheless, the propagation loss of LGS increases significantly as frequency and temperature increase, which limits the operating frequency of the SAW sensor based on LGS to 1 GHz. However, SAW resonator based on AlN/sapphire structure exhibits gigantic potential for high-temperature sensing applications due to its resistance to high temperatures, high Q-factor, and low propagation loss. In this work, an efficient model for SAW resonator based on AlN/sapphire is developed using the coupled mode (COM) theory combined with the finite element method (FEM). The influence of different numbers of interdigital transducers(IDT), reflective gratings, and different aperture lengths on device performance are investigated. Furthermore, the relationship between resonant frequency and temperature at various temperatures is simulated, which compares well with that of the experimental results. The investigation results show that the resonator works reliably in the temperature range of up to 500 °C and the operating frequency of up to 2.45 GHz. The frequency-temperature characteristics exhibit good linearity, with a temperature coefficient of-67×10^-6 °C^-1. This work provides an important reference for designing high-performance SAW high-temperature sensors.

Polymer Derived Ceramics (PDCs) thin-film thermocouples have the advantages of a simple preparation process and a stable high-temperature performance. They are very suitable for temperature measurement of hot-end components such as aircraft engine turbine blades. However, as the operating temperature of advanced engines increases, the upper limit of their temperature resistance needs to be improved. This article develops a precursor ceramic encapsulated PDCs: ITO/In₂O₃ thin film thermocouple. The encapsulation layer uses SiCN as the precursor solution and nano-Al₂O₃ powder as the filling material, and is prepared by the screen printing process. High-temperature test results show that the prepared sensor can survive at 1 500 °C in the short term and have stable output within 1 400 °C. The calibration test at 1 100 °C shows a linearity better than 0.999, with a multiple-cycle error of less than 1%.

The operating temperature of common acrylic-coated optical fibers is usually -65 °C to 80° C, and the working temperature of common high-temperature polyimide-coated optical fibers is up to 300 °C. At higher temperatures, metal-coated special optical fibers, such as aluminum-coated, copper-coated, and gold-coated fibers, are usually used for signal transmission. In this paper, the transmission loss of gold-coated fibers is tested at different ambient temperatures, and it is found that the transmission loss of gold-coated fibers varies greatly when the ambient temperature changes. For fiber optic temperature sensors based on the blackbody radiation principle, the error introduced by the variation in transmission loss can exceed 60 °C. On this basis, based on the transmission characteristics of light in different bands in gold-coated fibers, a dual-band correction method is proposed, which can correct the transmission loss of optical fibers caused by ambient temperature. After the correction, the error caused by the transmission loss is less than 15 °C.

Solid rocket motors are widely used in space launch vehicles, missile weapon propulsion, and spacecraft attitude and orbit control. Its tail flame temperature is a key parameter in evaluating propellant combustion performance and the engine efficiency. Due to the high temperature, high pressure and strong washout characteristics of the solid rocket motor exhaust flame, the test site environment is often accompanied by strong vibration, strong stray radiation, dust pollution and high noise, it's a challenge to temperature measurement techniques. In this paper, the development of contact and contactless temperature measurement techniques for solid rocket motor exhaust flame is summarized, and the advantages and disadvantages of the current techniques are analyzed. It is also pointed out that multispectral radiometric imaging thermometry and its temperature inversion algorithm are the current and future research frontiers.

Fiber Optic Gyroscope (FOG) is the core component of the fiber optic strapdown inertial navigation system, which has been widely used in aviation, aerospace, navigation and other fields. The scale factor is the main factor affecting the dynamic performance of FOG. Because the photoelectric devices inside FOG are highly sensitive to temperature vaviations, the scale factor error will be produced under the influence of temperature, which will affect the precision of FOG. In the variable temperature environment, each photoelectric device is heated unevenly, which leads to the hysteresis of the scale factor error. In this paper, the scale factor hysteresis error of FOG is studied, and a multi-temperature sensor measuring system is built. The source and characteristics of the scale factor hysteresis error are determined by the experimental results. Based on the above analysis, an error compensation algorithm based on gravitational search algorithm (GSA) and long short-term memory (LSTM) network is proposed. The parameters of LSTM network are optimized by GSA, and the LSTM model is used to compensate the scale factor hysteresis error. The experimental results show that the peak-to-peak value of scale factor error in the whole temperature range is reduced from 835.1×10^-6 to 38.02×10^-6 by the proposed algorithm. By comparing with the compensation results of multilayer perceptron (MLP) and traditional LSTM algorithm, the effectiveness of the proposed algorithm in scale factor hysteresis error compensation is further verified.

To meet the application requirements of inertial navigation, autonomous driving, and other fields, and to advance the development of micro-electromechanical systems (MEMS) silicon gyroscopes towards high precision, digitalization, and miniaturization, this paper presents the design and implementation of a MEMS silicon gyroscope interface ASIC with digital output, based on a 0.35 μm BCD process and a monolithic integration approach. A closed-loop drive scheme based on noise self-excitation is adopted, enabling the gyroscope to achieve harmonic vibration in the drive direction. The detection circuit uses a low-noise capacitive-to-voltage (C/V) conversion circuit to efficiently convert the small displacement signal into a voltage signal. Signal processing is performed using switched-capacitor phase-sensitive demodulation technology, combined with low-pass filtering, effectively suppressing noise interference and yielding a low-noise analog angular velocity output signal. To achieve the digital output of the silicon gyroscope's angular velocity, an integrated fourth-order feed-forward Sigma-Delta (ΣΔ) analog-to-digital converter (ADC) is designed to convert the analog angular velocity signal into a digital signal. The chip test results show that the dynamic range of the ΣΔ modulator reaches 110 dB, with a low-frequency noise floor of approximately -120 dB. The overall range of the gyroscope is ±200(°)/s, with a scale factor of 21 310 LSB/((°)/s), a nonlinearity of 178×10^-6, bias instability of 0.259(°)/h, and angle random walk of 0.028 7(°)/√h. The chip area is 4.3 mm×4.3 mm. By using the integrated interface ASIC to replace the traditional PCB-level system, the system's integration is significantly improved, successfully meeting the miniaturization requirements for MEMS silicon gyroscopes and promot-ing their development in high-precision digital applications.