摘要
月球作为光谱特性稳定、光强在探测器动态范围内的理想定标源,利用月球进行卫星在轨对月定标是提高辐射定标效率、监测探测器成像稳定性的重要手段之一。针对低轨高分辨率遥感卫星,提出了一种姿态机动对月定标方法,包括对月定标时机选择、对月定标卫星姿态规划以及载荷成像参数选取等技术。并基于某在轨运行的低轨光学遥感卫星成功开展了15次对月定标实验,卫星姿态角速度为0.06(°)/s,载荷积分时间为0.2938 ms,月相角覆盖-79.872°~89.236°。实验结果表明,卫星姿态实际执行情况符合设计的对月定标卫星姿态规划流程,且该对月定标方法具有很高的观测效率,仅耗时1500 s,不会影响卫星正常的对地观测任务;地面获取的15幅月球图像纹理清晰、稳定,对月空间分辨率优于1.18 km,图像DN值分布层次感较好;计算得出的月球辐照度分布趋势与国际上ROLO(Robotic Lunar Observatory)模型公布的趋势一致。实验结果验证了提出的对月定标方法的正确性及合理性,同时实现了中国首次低轨高分辨率遥感卫星姿态机动对月球多月相角观测,可为长期监测卫星探测器的成像稳定性和大量积累对月定标数据、建立中国自主可控的月球辐射模型提供可靠依据。
As an ideal calibration source,the moon has stable spectral characteristics and light intensity within the dynamic range of the detector.Thus,lunar calibration on-orbit is one of the important means to improve the efficiency of radiometric calibration and monitor the imaging stability of remote sensing satellites.Targeting low earth orbit and high-resolution remote sensing satellites,an on-orbit lunar calibration method,which includes imaging time,satellite attitude,imaging parameters of lunar observation,etc.,is proposed in this paper.Lunar observation experiments on a low-orbit optical remote sensing satellite were successfully conducted 15 times in July,2019,under the conditions of satellite attitude angular velocity of 0.06(°)/s and integration time of 0.2938 ms.The lunar phase angle covered the range of-79.872°to 89.236°.The results suggest that the satellite attitude of the actual implementation is in accordance with that of the design.Moreover,the lunar calibration method has high observation efficiency,which takes only 1500 s and will not affect the normal earth observation mission.Furthermore,the texture of 15 acquired images of the moon has a better distribution hierarchy of image DN value,and the spatial resolution is better than 1.18 km.The calculated lunar irradiance distribution trend is consistent with that of the RObotic Lunar Observatory(ROLO)model published internationally.The experimental results verified the correctness and rationale of the proposed method.Multiple lunar phase angle observation has been realized for the first time in China though the attitude maneuver of a low-orbit remote sensing satellite,which can provide a reliable basis for long-term monitoring of the imaging stability of the senor and accumulating a large amount of lunar calibration data to establish a lunar radiation model independently in China.
作者
朱军
李永昌
白照广
陆春玲
付凯林
茅歆白
张璐
ZHU Jun;LI Yong-chang;BAI Zhao-guang;LU Chun-ling;FU Kai-lin;MAO Xin-bai;ZHANG Lu(DFH Satellite Computer,LTD, Beijing 100094, China;National Satellite Meteorological Center, Beijing 100081, China)
出处
《光学精密工程》
EI
CAS
CSCD
北大核心
2020年第9期1913-1923,共11页
Optics and Precision Engineering
基金
国家重点研发计划基金资助项目(No.2018YFB0504900)
高分辨率对地观测系统重大专项青年基金资助项目(No.GFZX04061502)。
关键词
低轨卫星
高分辨率
姿态机动
对月定标
月球辐射模型
low-earth-orbit satellite
high resolution
attitude maneuver
lunar calibration
lunar radiation model
