漫反射激光测距和高精度测角一体化技术方案和实验研究

In the field of monitoring space debris, diffuse reflection laser ranging has broad application prospects. At present, diffuse reflection laser ranging observation is still in experimental stage. Affected by weather condition, the number and the geographical coverage of laser ranging stations and other factors, there are some difficulties in realizing multi-station laser ranging observation. And the orbit of objects can hardly be determined by ranging data only from one single station. According to the principle of orbit determination, the success rate and reliability of orbit determination of the object will be improved obviously if the tangential constraint of the object is afforded while laser ranging. In this project, we will develop the research of the integration scheme of diffuse reflection laser ranging and angle measurement with high precision on the basis of previous test. An optical telescope is planned to be installed on the present satellite laser ranging telescope system. The angle measurement with high precision can be realized while laser ranging, and key observational data can be obtained for the monitoring of space debris. The project aims at how to improve the precision of angle measurement and how to work simultaneously for laser ranging and angle measurement. We plan to establish a test integration system of diffuse reflection laser ranging and angle measurement with high precision by means of 60 cm satellite laser ranging telescope system at Sheshan Station of Shanghai Astronomical Observatory, carry out necessary experimental observation research, and provide the reference and technical basis for the development of similar type of equipments.

在空间碎片监测领域，漫反射激光测距技术具有广泛的应用前景。目前，非合作目标的漫反射激光测距处于试验阶段，受天气条件、测站数量和地理覆盖范围等因素的影响，实现多站测距存在较大难度，而仅靠单站漫反射激光测距数据又难以直接实现目标定轨。根据轨道理论，如果在测距同时，能够提供目标的切向约束，可显著提高目标定轨的成功率和可靠性。本项目拟在前期试验基础上，开展漫反射激光测距和高精度测角一体化技术方案研究，在现有激光测距系统上增加光学测角设备，在测距同时，实现高精度测角，为空间碎片监测提供关键数据。本项目重点研发如何提高测角精度、实现测距和测角同时工作的方法；同时，借助于上海天文台佘山60厘米激光测距望远镜系统，建立一套具备漫反射激光测距和高精度测角一体化技术的试验系统，开展必要的实验观测研究，为同类型设备的研制提供参考依据和技术基础。

在空间目标监测领域，漫反射激光测距技术比常规卫星激光测距具有更广泛的应用前景。现阶段，漫反射激光测距主要在夜间进行，且易受天气和可视弧段的限制，在测站数量有限、地理覆盖范围不大的情况下，实现多站测距存在较大难度；仅靠单站激光测距数据又难以实现目标定轨，制约了漫反射激光测距技术的应用。根据卫星定轨理论，如果在测距同时，能够提供目标的切向约束，可显著提高目标定轨的成功率和可靠性。本项目提出了在现有激光测距望远镜上增加光学测角设备，在测距同时，提供目标的切向约束，以提高单台站的空间目标监测能力。在项目实施期间，重点研制了跟踪低轨目标情况下测角资料处理方法，包括：大视场观测图像的预处理、拖长恒星星象的高精度提取和定心、复杂背景下的目标星象自动识别和CCD图像的视场畸变改正方法等。根据实测数据验证了方法和程序的可靠性。以上海天文台60cm激光测距望远镜为基础，通过增加短焦距、大视场的光学测角设备，建立了一套激光测距和测角一体化技术的试验系统。基于该试验系统开展了低轨目标的跟踪观测试验。试验结果表明，对于合作目标，利用激光测距与测角数据联合定轨，24小时轨道预报精度达到百米级；对于非合作目标，与TLE根数24小时预报的外符精度达到公里级，激光测距和测角一体化技术能够有效提高单站观测设备的监测能力。本项目研究成果可在激光测距望远镜上推广应用，也可为同类大型设备的研制提供参考依据和技术基础。