This paper investigates the potential for 83.4 nm imaging of the plasmaspheric dense oxygen torus, using simple models for core plasma density and composition to constrain a simulated image code. We derive the requirements for plasmaspheric O+ imaging, and the expected performance of an imager based on a slightly modified version of the IMAGE extreme ultraviolet camera. We find that such an imager can achieve a sensitivity of 0.69(s R pixel)−1, sufficient to capture the dense torus 83.4 nm signal with 25 min integration time. The background rejection ratios for this design are 1.5 × 10−4 at 58.4 nm and 7.4 × 10−8 for Lyman‐α. We discuss the effects of ion temperature and motion, and O++ glow. We compute simulated O+ images of the formation and global distribution of the dense torus. We also examine the possibility of direct observation of oxygen outflow from the ionosphere.
We present an algorithm and real time implementation for rapid code phase synchronization to direct sequence spread spectrum signals.The synchronization algorithm utilizes a complex matched filter to achieve code synchronization without sequential search over code phases, significantly reducing synchronization time. The algorithm is implemented on a Xilinx Spartan FPGA and is highly tailored to exploit the integrated signal processing resources on that device. Real time performance was demonstrated using less than one fourth of the device resources. Synchronization can be achieved with a latency of one code cycle and zero synchronization overhead in the signal.
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