The direction of arrival (DOA) is one of the most important parameters measured by electronic warfare systems. Monopulse direction finding techniques based on amplitude comparison have many advantages because of their simplicity but they generally have limited accuracy. There are many sources of error in such a system. This work focuses on improving the noise error. An algorithm is proposed for error reduction in amplitude comparison-based direction finding systems. The algorithm, based on signal level and DOA, adaptively utilises either adjacent or alternate antennas for the DOA measurement. No additional hardware is required for the implementation of this algorithm. A prototype system is developed using spiral antennas and the performance of the proposed technique is compared against traditional ratio-based and correlation-based amplitude comparison schemes. Simulations and laboratory experiments show that the DOA accuracy can be improved by an average of 36 and 21% as compared to the ratio-based and correlation-based methods, respectively.

中文翻译：

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通过自适应斜视选择提高基于幅度比较的无源测向系统的精度

到达方向（DOA）是电子战系统测得的最重要参数之一。基于振幅比较的单脉冲测向技术由于其简单性而具有许多优点，但是它们通常具有有限的精度。在这样的系统中有许多错误来源。这项工作的重点是改善噪声误差。提出了一种在基于幅度比较的测向系统中减少误差的算法。该算法基于信号电平和DOA，自适应地利用相邻或备用天线进行DOA测量。实现此算法不需要其他硬件。使用螺旋天线开发了原型系统，并将所提出技术的性能与传统的基于比率和基于相关的幅度比较方案进行了比较。仿真和实验室实验表明，与基于比率的方法和基于相关的方法相比，DOA的平均精度分别提高了36％和21％。