Study On Methodology Of Lunar-based Earth Observation For Global Change

As a planet, the Earth’s long-term natural evolution and dynamic changes with large scale have close relationship with human survival environment. However, global change science demands that the components of the earth should be understood and studied as a unified system. Nowadays, the improvements of Earth observation technology make it possible to analysis and simulate the environmental change of the earth system. However, space borne, airborne and in-situ observations have large limitations for earth’s global environmental change monitoring. These technologies, without exception, could only monitor surface of the Earth surface regionally at the same time, meanwhile the observation period is always couple of weeks or even longer. The results from these methods arc not satisfied for large-scale and short-time globe changes study. The moon, as the earth’s only natural satellite, is the nearest celestial body apart from the earth, and the only planet human can reach currently, what’s more, the motion law of the moon is well known, and its surface environment has been studied as well. The lunar-based has become an ideal place for the space observations of the global change. But no actual effective data for the lunar-based exploration could be obtained for research. The thesis proposes a new idea that it sets up a sensor on the moon in order to monitor global change of the earth, and the study method is based on the sun-earth-moon simulation system, through this, the regularity of the observation for large-scale science phenomenon on the earth is researched.The sun-earth-moon simulation is the most important part of the research for the lunar-based earth observation, and it combined with the application of astronomical information management,3D graphic simulation and space information science research, including the database technique, the numerical calculation simulation and other disciplines as well, and it provides the relative motion simulation and information management platform. It has important scientific significance to program the related work without the effective data for the lunar-based earth observation.The paper starts on summarizing the global change research based on the lunar platform, mainly includes the concept for the lunar-based earth observation and related research progress, what’s more, the idea about it is considered. To realize the science target, it needs to know the spatial relationship and environment between the earth and the moon. According to the sun-earth-moon track characteristics, the NASA JPL planet ephemeris has been introduced, and the data structure and algorithm with the ephemeris DE405also been designed, in order to calculate the real-time track position and speed in the sun centroid coordinate, moreover the results have been saved in file way. And then introduces system structure tor the OpenGL graphics library and drawing principle, the sun-earth-moon operational system is realized with it. Finally the track position of the moon in relative to the earth is converted to the longitude and latitude on the earth surface. The project position of the moon’s centroid in the earth surface has been statistically analyzed, that is called the observation geometry analysis. At the same time the images and other data have been downloaded from the data download center of NASA WorldWind. and it includes the cloud, cyclones and water vapor dynamic, what’s more, they have been demonstrated in this system from the lunar-based platform.