Abstract：We have studied the issues that poor survivability and high processing delay of single-layer satellite networks, and complex management and high link redundancy of triple-layer satellite networks, and propose an optimal design scheme of double-layer hybrid satellite network. In our proposed scheme, the networking analysis and constellation design for MEO and LEO satellites have been presented by using Walker constellation and polar orbit constellation respectively. Meanwhile, aiming at the problem that the traditional satellite coverage performance index cannot be used to evaluate the satellite constellation with different configurations generally, a unified evaluation model of satellite constellation is proposed based on Analytic Hierarchy Process(AHP). Simulation results show that the proposed scheme can not only improve the percentage of coverage, but also effectively reduce the average gap duration and average response time, so then meet the overall design requirements for all-day coverage in China.

Abstract：As evidence theory algorithms fail to identify and distinguish the complex and unstable radar signals efficiently, the improvement have be presented for the algorithm of fusion recognition based on evidence theory. Firstly, add the classification strategy to classifying the signals and use the consistency of ranking method to measuring the weight value of each parameters. Then, the improved evidence fusion rules is subsequently applied to exercise fusion processing on the similarity of parameters concerning each signal and the trust value concerning target framework of each signal in order. Finally, finish the recognition according to the final trust value. The results of simulation reveal that the improved algorithm can exert favorable effect on the distinction of unknown complex radar signals, with higher recognition rate and less consumption time, which is more fit for the actual signal fusion recognition.

Abstract：Based on the grid ionospheric correction algorithm of BDSBAS,the paper discusses how to calculate the IGP vertical ionospheric delay by the IPP vertical ionospheric and tests the grid point ionospheric vertical delay error(GIVE).The results show that grid ionospheric model is a kind of high accuracy ionospheric delay correction algorithm and the delay of ionospheric grid is the key of the grid model;selects near the IGP reference station to calculate the vertical grid delay is more accurate and is also beneficial to obtain high-accuracy ionospheric correction effect;Additionally,the correction error is in a normal range,verifies the algorithm of GIVE is workable in the area of China and can limit the grid point ionospheric delay error with a confidence level of 99.9%.

Abstract：In order to ensure high-speed stable storage rate of high-speed large-capacity space-borne storage, we must to manage the bad blocks that occur when writing because of single particle flipping and exceeding erase limits in NAND Flash chip. File-based bad block management links all bad blocks of four-level pipeline into one file, links unused blocks of four-level pipeline into four separate files, and links used blocks into many different payload files. In addition, adopting a four-level pipeline ping-pong buffer mechanism replaces the write failure blocks fast. The file-based bad block management, which runs in the model task, resolves the problem of storage rate jitter when the data is written in a bad block, and stores the multi-payload data into different payload files with four times the write rate of one-level pipeline. Therefore, file-based bad block management ensures the correctness and integrity of the payload data.

Abstract：A high-speed image storage and real-time display system is designed for telemetry system of aiming at the problems of large data volume, high-speed and inability to store display directly. The system takes the Spartan 6 series FPGA as the core processor, and uses the full mode Camera Link interface to gather the image data of CMOS camera output. The system of possessing high-speed image storage and real-time display uses technology of DDR3 Ping-Pong cache to write image data into a disk array consisting of SATA controllers as well as through Gigabit Ethernet interface upload to computer after analysis and processing. Image data is converted to the VGA resolution format of the 1 024×768 pixels in the form of pumping frames and reducing resolution. Finally the system conduct the image real-time display through the VGA interface. What the experimental results show that the system can store and display the high-speed image data with 2 048×2 048 pixels and frame frequency with 150 f/s resolution.

Abstract：In order to satisfy the requirement of solar irradiance spectrometer spectral calibration on the satellite, a mercury-lamp source is designed based on its characteristics which can be described as high voltage to glow and low voltage for work. The single-ended flyback topological structure and four level dual voltage rectifier are used to provide the high glowing voltage. And the degenerative feedback is designed to current constant. The glowing voltage and working voltage can be switched automatically without the microcontroller. Both the usability and the reliability in low temperature of the source are improved. The experiments show that the current precision of the mercury-lamp source designed is 0.000 21, the current adjustment rate is 0.001 8, the current stabilization coefficient is 0.009. The mercury-lamp source can work reliably in low temperature and satisfy the system requirement of the load.