摘要
机载平台对抗干扰全自主的天文导航系统提出了迫切的需求,现有小视场跟踪式白天测星天文导航设备存在适装性差、精度受限等问题,难以满足机载平台对导航精度日益苛刻的需求,满足海拔10~20 km高度测星的机载大视场白天测星问题亟待解决,大部分研究只停留在理论分析和光学系统设计阶段,未见实际应用和试验。针对上述需求,在分析大气背景辐射的基础上,选取短波红外测星传感器并设计了白天测星光学系统,对选用的探测器和设计的光学系统在10 km海拔高度的单像元电子数、背景电子数和测星能力进行了分析,研制了一款轻量化机载平台用大视场白天测星星敏感器样机,工作波段为1.4~1.7μm。开展了高空飞行搭载试验,研制的星敏感器样机在海拔8 km可实现多星检测识别,测星能力优于H波段1.3等星,在海拔20 km可实现H波段2.7等星探测,能够满足设计要求。高空飞行实验表明机载大视场白天测星技术可以实现10~20 km海拔高度多星探测识别,对提升机载平台自主导航精度和定位精度具有重要意义。
Objective Astronomical navigation utilizes natural celestial bodies as navigation targets,offering the advantages of being free from external interference and possessing strong autonomy.This method can effectively address the issue of satellite navigation systems being susceptible to interference,which renders satellite/inertial integrated navigation systems inadequate for meeting the safety and high-precision autonomous navigation requirements of airborne platforms.While some airborne platforms are equipped with astronomical navigation systems based on tracking axis and small-field-view star sensors,these systems are burdened by weight and tracking axis errors that affect accuracy.In contrast,large-field-view star sensors,which do not require a tracking axis system,offer significant advantages in terms of accuracy,size,weight,lifespan,maintainability,reliability,and cost.However,despite these benefits,there have been no practical applications or reports of large-field-view star trackers being used at the altitude range of 10-20 km,where most airborne platforms operate.To meet the autonomous navigation equipment needs of airborne platforms,research is being conducted on daytime startracking technology for large-field-view star trackers at an altitude of 10-20 km.Methods Based on a thorough analysis of atmospheric background radiation distribution data,this study aims to optimize the working wavelength band for daytime star measurement.It conducts a comprehensive analysis of the capabilities of airborne large-field-view star trackers for daytime star measurement,considering factors such as optical system design,imaging sensor selection,and star measurement accuracy.To test its findings,an engineering prototype of the star tracker was developed and its performance was evaluated through a daytime star measurement experiment on a flight test vehicle.Results and Discussions A large-field-view daytime star tracker optical system has been designed and an engineering prototype has been developed for an airborne application.The prototype weighs less than 1.5 kg and has been successfully tested on a flight test vehicle.At altitudes above 8 km,the engineering prototype is capable of multi-star measurement and accurately outputting attitude,with a star measurement capability of over 1.3 magnitude(H-band)(Fig.4).At an altitude of approximately 20 km,the star tracker can reliably detect more than 10 star targets and output stable attitude measurements.In fact,at this altitude,the engineering prototype has a measurement capability of over 2.7 magnitude(H-band)even during the daytime.Conclusions According to the requirements of a large field-of-view star tracker for an airborne platform,a 10-20 km airborne large field-of-view daytime star measurement technology has been proposed.The atmospheric background radiation,transmittance,and the daytime star measurement ability of the star tracker at the working altitude of the airborne platform were analyzed,including factors such as the number of electrons for each pixel and the number of sky background electrons at an altitude of 10 km.An engineering prototype was designed and a daytime star measurement experiment was conducted.The experimental data showed that the designed star tracker could achieve continuous and stable output at an altitude of more than 10 kilometers during the daytime.Additionally,for the first time,the daytime large field-of-view star measurement was successfully achieved at altitudes of 10-20 km.The daytime star measurement ability of the star tracker could reach the second-class star in the short-wave infrared H-band.High altitude flight tests have demonstrated that the airborne large field-of-view daytime star measurement technology can detect and identify multiple stars at altitudes of 10-20 km,which is of great significance in improving the autonomous navigation and positioning accuracy of airborne platforms.
作者
张前程
钟胜
李显成
ZHANG Qiancheng;ZHONG Sheng;LI Xiancheng(School of Artificial Intelligence and Automation,Huazhong University of Science and Technology,Wuhan 430074,China;National Key Laboratory of Science and Technology on Multi-Spectral Information Processing,Huazhong University of Science and Technology,Wuhan 430074,China;Huazhong Institute of Electro-Optics-Wuhan National Laboratory for Optoelectronics,Wuhan 430223,China)
出处
《红外与激光工程》
北大核心
2025年第7期336-342,共7页
Infrared and Laser Engineering
关键词
机载平台
白天测星
天空背景
信噪比
airborne platform
daytime star measurement
sky background
SNR
