嫦娥三号粒子激发X射线谱仪红外距离感知方法

Near Infrared Distance Sensing Method for Chang'E-3 Alpha Particle X-Ray Spectrometer

粒子激发X射线谱仪(APXS)是我国嫦娥三号卫星月球巡视器的有效载荷之一,其主要目的是对月面土壤和岩石完成就位探测和离线分析,距离感知功能是保障APXS有效探测的一项重要功能。本文首先简要介绍了APXS系统,分析了距离感知功能的特殊要求和约束,然后提出了一种利用响应曲线拐点的新型红外距离感知方法。通过理论推导证明了本方法的算法可行性,并且设计试验验证了本方法。理论分析表明,尽管该方法对工作温度和月面反射率不敏感,但是强烈的太阳红外辐射环境可能引起光敏器件饱和。解决措施是适当降低器件增益并避免太阳光直射。

Alpha particle X-ray spectrometer （APXS） is one of the payloads of Chang＇E-3 lunar rover, the scientific objective of which is in-situ observation and off-line analysis of lunar regolith and rock. Distance measurement is one of the important func- tions for APXS to perform effective detection on the moon. The present paper will first give a brief introduction to APXS, and then analyze the specific requirements and constraints to realize distance measurement, at last present a new near infrared dis- tance sensing algorithm by using the inflection point of response curve. The theoretical analysis and the experiment results verify the feasibility of this algorithm. Although the theoretical analysis shows that this method is not sensitive to the operating tem- perature and reflectance of the lunar surface, the solar infrared radiant intensity may make photosensor saturation. The solutions are reducing the gain of device and avoiding direct exposure to sun light.