The rapid relative motion of satellites causes the burst spread-spectrum signals to produce a Doppler frequency shift. In low signal-to-noise ratio (SNR) environments, the traditional acquisition algorithms are limited in their abilities to capture large Doppler frequency shift when signals are seriously disturbed by noise. In view of the above problems, this paper designs a parallel burst spread spectrum signal acquisition algorithm based on pilot information and Partial Match Filter-Fast Fourier Transform (PMF-FFT). The algorithm utilizes pilot information and multi-path parallel processing method to achieve fast acquisition of Doppler frequency shift and PN code, which greatly reduces the acquisition time of burst signal. Firstly, the mathematical model and the acquisition loss of the algorithm are analyzed in detail. Then, the scallop loss of the acquisition system is reduced by zeroing the FFT. Finally, a method of the shortest synchronization segment based on a constant false-alarm rate and a specified detection probability is designed. The simulation results show that the acquisition probability of the proposed algorithm reaches 99 % for burst signals under the -31 dB signal-to-noise ratio when the false alarm probability is 10^-6，which verifies the feasibility of the design method.

The development of wireless communication technology has imposed strict requirements on antennas, including high-frequency operation, miniaturization, and strong directivity, to support higher data transmission rates in the future. Due to inherent amplitude and phase differences among channels in millimeter-wave chips and multi-antenna arrays, as well as additional amplitude and phase differences caused by factors such as temperature characteristics and aging during operation, beamforming accuracy can be significantly degraded. To mitigate the impact of inter-channel amplitude and phase differences on beam control, this paper proposes a near-field calibration algorithm based on plane wave spectrum expansion. The algorithm constructs a signal model between the antenna under test (AUT) and the probe using plane wave spectrum theory. Based on this model, a virtual signal for calibration measurement is generated and compared with the measured signal. A genetic algorithm is used to optimize the difference between the virtual and measured signals, and the initial excitations of the millimeter-wave array antenna are determined when the difference reaches its minimum. To validate the effectiveness of the proposed calibration algorithm, a four-element millimeter-wave linear array was calibrated. The probe scanning range was approximately one-third of the array aperture. The obtained amplitude calibration error range was ±0.43 dB, and the phase calibration error range was ±4.6°, achieving high-precision calibration.

Aiming at the absolute and relative location service needs of low-altitude flight drones in complex electromagnetic environments, a three-dimensional distributed drone cooperative localization method based on high-precision ranging information is proposed. All nodes in the cluster are equipped with navigation positioning sensors with the same accuracy, and use the inertial error as a state variable, the height value of the altimeter as a height measurement and 0.1 Hz visual matching information as position and speed measurements to correct the absolute positioning error of the nodes. Use the ranging values of the nodes as cooperative measurements to correct the relative positioning error, and use the extended Kalman filter to fuse the measuring range and inertial/altimeter/vision system output. Construct the flight test scene of the 6-node drone group to complete the simulation verification of low-altitude flight scenes. Verified, through the cooperative positioning algorithm, the absolute position accuracy is improved by 61%, and the relative positioning accuracy increases by 93%, which proves the effectiveness of the cooperative localization method.

By constructing an angle tracking loop model and performing simulations in the phased array TT&C (Telemetry, Tracking and Command) system, it is used to assist in designing the parameters for the α-β filtering estimation algorithm in the angle tracking loop and the closed-loop period and delay time of the entire loop. Firstly, the equipment composition of the phased array antenna angle tracking system is introduced, and a simulation model of the angle tracking loop is constructed. Then, when the parameters of the filtering estimation algorithm and the closed-loop period and delay time of the angle tracking loop change, the step signal is used to test the dynamic response performance of the angle tracking loop, and based on this, the design parameters of each link in the loop are determined. Subsequently, constant-velocity signals and sinusoidal signals are used to simulate the maneuvering characteristics of the flight target, and the lag error of the angle tracking loop is simulated to verify whether the design parameters meet the usage requirements of the system. Finally, the sinusoidal signal is used to simulate the disturbance characteristics of the antenna carrier platform. The anti-disturbance performance of the angle tracking loop is verified through loop lag error simulation, and by simply improving the filtering estimation algorithm, the anti-disturbance performance of the loop is improved. Experimental results demonstrate that modeling and simulation of the angle tracking loop enable rapid parameter and algorithm design for all components in the loop, significantly reducing trial-and-error costs.

This study investigates the application of flower-shaped bionic topology in phased array antenna liquid cooling systems through computational fluid dynamics (CFD) simulations and experimental validation. The phased array antenna comprises a rectangular transmitting module, 4 L-shaped receiving modules and 12 rectangular receiving modules. All these three types of liquid cooling plates are designed to form either a flower-shaped bionic topology or a fully parallel topology. Comparative analysis reveals that the flower-shaped bionic topology offers a highly efficient thermal control solution. The temperature gradient of the antenna employing flower-shaped bionic topology is significantly smaller than that of the fully parallel topology. The temperature difference between modules is controlled to ±3 ℃, representing an 8%~15% improvement over the fully parallel topology.

The radar seeker simulation system is crucial for the process of the seeker striking the target accurately. As simulation systems become more complex and data processing demands grow, traditional serial computing methods can no longer satisfy the strict real-time requirements of radar seeker digital simulations. To address the challenge of lengthy simulation times in the radar seeker simulation process, this paper proposes a full-process digital real-time simulation method. Firstly, the core components of the traditional full-process simulation architecture—receiving and controlling system commands, simulating echo data reception, SAR imaging processing, uploading imaging results, and dynamically updating the user interface—are restructured into a pipeline-based parallelization framework. Secondly, the SAR imaging algorithm's primary steps are parallelized using the OpenMP multi-core parallel programming model on multi-core CPUs. Furthermore, the high-performance mathematical computing library FFTW3 is introduced to quickly realize the Fourier transform of the imaging algorithm to accelerate the processing speed of the SAR imaging algorithm. Finally, the simulation results show that compared with the traditional serial simulation, the acceleration ratio of the whole process design method reaches about 100 times, and the similarity of SAR images before and after acceleration is close to 1. Under the premise of consistent processing accuracy and effect, this approach enables full-process real-time simulation of the radar seeker system, showcasing promising prospects for practical engineering applications.

The task volume of TT&C equipment executing satellite management tasks is increasing day by day. The daily shutdown maintenance, performance index testing and increasing workload of equipment have become contradictory. Equipment maintenance and performance index testing demand efficient automated testing methods. This article researches the integrated operation management system based on lightweight cloud, analyzes the software and hardware composition of the automated testing system, deploys automated testing software on the integrated operation management system, and improves the reliability of software operation. It has also proposed an automated testing strategy for high-density task states, optimized the automated testing process, and implemented the function of rapid and automated testing of TT&C performance indices. By testing the effective isotropic radiated power—EIRP value of the system, and applying the automated testing system in practice, the testing efficiency has been significantly improved.

In response to the development trend of on-board routing devices, namely the improvement of interaction rate, bandwidth increase, and lightweight design, this paper proposes a design scheme for on-board high-speed switching algorithm based on improved polling. This scheme adopts a two-level queue scheduling algorithm based on the combination of the improved RR(Round Robin) polling scheduling algorithm and PBPW (Priority-based Bandwidth Privilege with Weighting) algorithm. In the first level scheduling, priority polling scheduling is introduced to ensure that high priority data frames can be forwarded first. A cache sharing mechanism is opened to avoid congestion and resource waste to a certain extent. In the second level scheduling, thresholds are assigned to each link to avoid certain links from being unable to receive service due to hunger, while also preventing congestion issues in other links. Compared with traditional simple queue scheduling algorithms based on FIFO (First In First Out), this improved polling scheduling mechanism significantly improves the forwarding rate of on-board routers and reduces forwarding latency. In addition, priority forwarding of high priority data frames has been achieved through polling, further optimizing the performance of the router.

In this paper, we propose a novel method of attitude determination for spinning vehicles based on standalone GNSS. A baseband algorithm is first developed to resolve the shadowing effect encountered by 4-antenna receivers mounted on spinning vehicles, enabling continuous and precise signal tracking. Then the particular geometry of the 4-antenna configuration is exploited to yield differential ENU-velocity vectors from co-located antennas. By taking the inner product, the vehicle's pose information is derived from the orthonormality of rotation matrices, and yields the roll rate in the body frame. Finally, we use the roll rate to devise linearly independent differential vector pairs and solve for the rotation matrix in the linear system relating ENU velocities and body-frame velocities. The attitude information, defined by Tait-Bryan angles, can thereby be resolved. The algorithm presented is implemented in a 4-antenna real-time GNSS receiver and experiments are carried out with a spinning cylindrical platform. The results are confirmed via evaluation of the PVT results and comparisons with the platform's true attitude.

With the ongoing advancements in equipment informatization and lightweight design, the development of navigation guidance and control (GNC) systems faces escalating complexity, while demands for system miniaturization and weight reduction grow increasingly urgent. System-in-Package (SiP), a high-density integrated packaging technology, addresses these challenges by encapsulating multiple functional chips into compact cavities, thereby achieving enhanced integration and system miniaturization. To meet the miniaturization requirements of GNC systems, this study presents a GNC information processing microsystem circuit designed using SiP technology. The circuit employs a DSP+FPGA architecture, integrates diverse interface and memory chips, and leverages mature ceramic substrate microsystem integration techniques. Comprehensive multi-physics simulations were conducted to validate the design. Experimental results demonstrate normal circuit functionality and full compliance with design specifications. Compared to the prototype verification board, the optimized circuit exhibits dimensions of 45 mm×45 mm×11 mm and a weight of approximately 60 g. Substituting traditional board-level systems with this circuit significantly improves product integration and fulfills critical miniaturization requirements for control systems.