天文研究与技术-国家天文台台刊
天文研究與技術-國傢天文檯檯刊
천문연구여기술-국가천문태태간
ASTRONOMICAL RESEARCH & TECHNOLOGY-PUBLICATIONS OF NATIONAL ASTRONOMICAL OBSERVATORIES OF CHINA
2014年
3期
264-274
,共11页
胡开宇%艾力·玉苏甫%刘奇
鬍開宇%艾力·玉囌甫%劉奇
호개우%애력·옥소보%류기
天线%自适应滤波器%脉冲星%仿真
天線%自適應濾波器%脈遲星%倣真
천선%자괄응려파기%맥충성%방진
Antenna%Adaptive filter%Pulsar%Simulation
为了使天线系统接收和显示的信号更清晰,达到消除系统噪声和电磁干扰的目的,针对中国科学院新疆天文台南山观测基地对射电天文观测和深空探测(探月工程和火星探测)的特殊要求,利用Matlab/Simulink强大的数值计算与仿真功能实现了一种依据自适应方法滤除噪声的滤波器。首先选择脉冲星1910+0728和1913-0440的观测信号为滤波参考信号。在Matlab上通过编写M文件设计了滤波算法并有效滤除了噪声。然后运用Simulink进行建模仿真,通过不断改变系统阶数与步长找到了滤波效果最好的自适应滤波器,确定了其最优参数为8阶,迭代步长为0.005。实验表明在这种阶数和步长下,滤波器能在保证快速滤波的前提下有效地还原接收信号的轮廓,将偏差降到最小。仿真最终结果表明自适应滤波器滤波效果良好,实用性强,满足了射电天文观测和探月的需求。
為瞭使天線繫統接收和顯示的信號更清晰,達到消除繫統譟聲和電磁榦擾的目的,針對中國科學院新疆天文檯南山觀測基地對射電天文觀測和深空探測(探月工程和火星探測)的特殊要求,利用Matlab/Simulink彊大的數值計算與倣真功能實現瞭一種依據自適應方法濾除譟聲的濾波器。首先選擇脈遲星1910+0728和1913-0440的觀測信號為濾波參攷信號。在Matlab上通過編寫M文件設計瞭濾波算法併有效濾除瞭譟聲。然後運用Simulink進行建模倣真,通過不斷改變繫統階數與步長找到瞭濾波效果最好的自適應濾波器,確定瞭其最優參數為8階,迭代步長為0.005。實驗錶明在這種階數和步長下,濾波器能在保證快速濾波的前提下有效地還原接收信號的輪廓,將偏差降到最小。倣真最終結果錶明自適應濾波器濾波效果良好,實用性彊,滿足瞭射電天文觀測和探月的需求。
위료사천선계통접수화현시적신호경청석,체도소제계통조성화전자간우적목적,침대중국과학원신강천문태남산관측기지대사전천문관측화심공탐측(탐월공정화화성탐측)적특수요구,이용Matlab/Simulink강대적수치계산여방진공능실현료일충의거자괄응방법려제조성적려파기。수선선택맥충성1910+0728화1913-0440적관측신호위려파삼고신호。재Matlab상통과편사M문건설계료려파산법병유효려제료조성。연후운용Simulink진행건모방진,통과불단개변계통계수여보장조도료려파효과최호적자괄응려파기,학정료기최우삼수위8계,질대보장위0.005。실험표명재저충계수화보장하,려파기능재보증쾌속려파적전제하유효지환원접수신호적륜곽,장편차강도최소。방진최종결과표명자괄응려파기려파효과량호,실용성강,만족료사전천문관측화탐월적수구。
In order to make signals received by radio-telescope antenna systems more clearly recognizable , i.e.with system noise and electromagnetic interferences reduced to desired levels , we design a type of adaptive filters and numerically simulate their performances using the powerful Matlab /Simulink tools .Our adaptive filters are to meet the special requirements on radio-astronomy observations and deep-space explorations ( of the Moon and Mars ) at the Nanshan Station of the Xinjiang Astronomical Observatory , Chinese Academy of Sciences .In an earlier section of this paper we present signals from the pulsars 1910+0728 and 1913-0440 ( Liu Qi, private communication ) , which serve as reference signals for testing the filters.We write an algorithm in a Matlab M-file realizing the adaptive filtering .The file is easily understandable and allows other people to study .Our simulation tests with the pulsar signals show that the filters can effectively reduce the noise .In addition , we use the Simulink in the Matlab for modeling and simulating antenna systems ( including the filtering ) .By extensively changing the order and the iteration step size of a modeled filter , we find the optimal parameters for our adaptive filter:an order of eight and a step size of 0.005 .In the process , we have also verified that filters of this type can effectively restore profiles of received signals and minimize errors while fast processing signals .The simulation results and subsequent analyses of these ( particularly the results with the Simulink ) show that our adaptive filters can practically result in fine outputs and meet the needs of radio astronomy .With the rapid development of radio astronomy in China and the progress of building the 110m radio telescope in Xinjiang , filters as ours will be widely used for deep-space explorations and astronomical observations .