程序核心 meaning in English

program kernel

The orbit simulation program mainly concentrates on orbit calculation . this thesis first introduces the fundamental knowledge of orbit dynamics , including orbit perturbation and spacecraft attitude control
轨道仿真程序核心部分是轨道计算，本文首先介绍了轨道动力学基础，包括轨道摄动问题，以及飞行器姿态控制等基础知识。
The technology of the three - dimensional figure is the key technology of such a lot of important application as virtual reality and real - time emulation and mutual three - dimension design , etc . because the technology of the three - dimensional figure involves a lot of algorithms and professional knowledge , the fast development of three - dimensional application program has certain difficulty , so there is a very great meaning in the research of the three - dimensional engine
三维图形技术是虚拟现实、实时仿真以及交互三维设计等许多重要应用的关键技术。由于三维图形技术涉及到许多算法和专业知识，要快速的开发三维应用程序是有一定困难的，因此三维引擎(三维程序核心)的研究就有很大的意义。