PolyU scientists make great strides in lunar mapping

 　　HONG KONG, Sept. 9 (Xinhua) -- The Hong Kong Polytechnic¹ University (PolyU) announced Friday that its surveying experts had successfully developed methodologies for precise mapping of the Moon, after intensive analysis of the data captured by the Chinese lunar orbiter ChangE-1 and other lunar exploration missions.

　　According to the PolyU, the team has made significant contributions to lunar mapping. Their efforts culminated² in the development of a unique and innovative³ approach to the creation of accurate 3D models of the lunar surface.

　　The team has produced the most updated parameters⁴ of the lunar figure (the shape of the moon), which is essential for lunar mapping using 17.5 million laser altimetry measurements from the ChangE-1and the Japanese SELENE missions.

　　In addition, they also used the new topographic and gravity models to calculate improved crustal thickness and mass distribution of the Moon and established that the average thickness of the Moon's crust is about 40 km on the near side and 50 km on the far side.

　　It was introduced that the resulting lunar mapping was the hard work of a dedicated⁵ research team led by Professor Chen Yong-qi, Emeritus⁶ Professor of the Department of Land Surveying and Geo-Informatics, who is also serving on the Expert Committee of China's Lunar Exploration Programme (ECCLEP), with the concerted efforts of team members Prof. Chen Wu, Prof. Ding Xiao-li, Prof. Baki Iz, Dr. Bruce King, and Dr. Wu Bo.

　　According to Chen Yong-qi, the lunar mapping project started in 2006. The primary objective was to develop the methodologies and techniques for mapping the Moon surface, which is much more challenging than mapping the Earth's surface because of very few surveyed control points which are essential for accurate map making.

　　Statistics showed that there were only fourteen lunar laser ranging retro reflectors (LRRR) and Apollo lunar surface experiment package (ALSEP) transmitter sites with accurately⁷ known coordinates⁸ available only on the near side of the Moon, installed by the U.S. Apollo and former Soviet⁹ Union Luna missions in the 1960s.

　　Moreover, according to the team, the gravitational field of the Moon is not as well-known as that of Earth, which means the accuracy of the computed¹⁰ lunar satellite's position at any given time is lower than for Earth satellites, thus degrading the mapping accuracy and reliability¹¹.

　　In addition, the team expressed that highly reflective lunar surface created significant problems for the automatic processing of images to develop 3D models using the technique of photogramemtry, which is a widely used and highly reliable technique for the creation of maps and 3D models on Earth.

　　Furthermore, the team also revealed they had a plan to compare such data with other data sources in order to evaluate the performance of the ChangE mapping sensors¹². Since Chen Yong-qi is serving on the ECCLEP, the team has direct access to more recent data captured by the ChangE satellite.

1 polytechnic   

adj.各种工艺的，综合技术的；n.工艺(专科)学校；理工(专科)学校

参考例句：

• She was trained as a teacher at Manchester Polytechnic.她在曼彻斯特工艺专科学校就读，准备毕业后做老师。
• When he was 17,Einstein entered the Polytechnic Zurich,Switzerland,where he studied mathematics and physics.17岁时，爱因斯坦进入了瑞士苏黎士的专科学院，学习数学和物理学。

2 culminated   

v.达到极点( culminate的过去式和过去分词 )

参考例句：

• a gun battle which culminated in the death of two police officers 一场造成两名警察死亡的枪战
• The gala culminated in a firework display. 晚会以大放烟火告终。 来自《简明英汉词典》

3 innovative   

adj.革新的，新颖的，富有革新精神的

参考例句：

• Discover an innovative way of marketing.发现一个创新的营销方式。
• He was one of the most creative and innovative engineers of his generation.他是他那代人当中最富创造性与革新精神的工程师之一。

4 parameters   

因素，特征； 界限； （限定性的）因素( parameter的名词复数 )； 参量； 参项； 决定因素

参考例句：

• We have to work within the parameters of time. 我们的工作受时间所限。
• See parameters.cpp for a compilable example. This is part of the Spirit distribution. 可编译例子见parameters.cpp.这是Spirit分发包的组成部分。

5 dedicated   

adj.一心一意的；献身的；热诚的

参考例句：

• He dedicated his life to the cause of education.他献身于教育事业。
• His whole energies are dedicated to improve the design.他的全部精力都放在改进这项设计上了。

6 emeritus   

adj.名誉退休的

参考例句：

• "Perhaps I can introduce Mr.Lake Kirby,an emeritus professor from Washington University?"请允许我介绍华盛顿大学名誉教授莱克柯尔比先生。
• He will continue as chairman emeritus.他将会继续担任荣誉主席。

7 accurately   

adv.准确地，精确地

参考例句：

• It is hard to hit the ball accurately.准确地击中球很难。
• Now scientists can forecast the weather accurately.现在科学家们能准确地预报天气。

8 coordinates   

n.相配之衣物；坐标( coordinate的名词复数 )；（颜色协调的）配套服装；[复数]女套服；同等重要的人（或物）v.使协调，使调和( coordinate的第三人称单数 )；协调；协同；成为同等

参考例句：

• The town coordinates on this map are 695037. 该镇在这幅地图上的坐标是695037。 来自《简明英汉词典》
• The UN Office for the Coordination of Humanitarian Affairs, headed by the Emergency Relief Coordinator, coordinates all UN emergency relief. 联合国人道主义事务协调厅在紧急救济协调员领导下，负责协调联合国的所有紧急救济工作。 来自《简明英汉词典》

9 Soviet   

adj.苏联的，苏维埃的；n.苏维埃

参考例句：

• Zhukov was a marshal of the former Soviet Union.朱可夫是前苏联的一位元帅。
• Germany began to attack the Soviet Union in 1941.德国在1941年开始进攻苏联。

10 computed   

adj.[医]计算的，使用计算机的v.计算，估算( compute的过去式和过去分词 )

参考例句：

• He computed that the project would take seven years to complete. 他估计这项计划要花七年才能完成。 来自《简明英汉词典》
• Resolving kernels and standard errors can also be computed for each block. 还可以计算每个块体的分辨核和标准误差。 来自辞典例句

11 reliability   

n.可靠性，确实性

参考例句：

• We mustn't presume too much upon the reliability of such sources.我们不应过分指望这类消息来源的可靠性。
• I can assure you of the reliability of the information.我向你保证这消息可靠。

12 sensors   

n.传感器，灵敏元件( sensor的名词复数 )

参考例句：

• There were more than 2000 sensors here. 这里装有两千多个灵敏元件。 来自《简明英汉词典》
• Significant changes have been noted where sensors were exposed to trichloride. 当传感器暴露在三氯化物中时，有很大变化。 来自辞典例句