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101.
GPS-based sea level measurements to help the characterization of land contamination in coastal areas
P. Bonnefond P. Exertier O. Laurain P. Thibaut F. Mercier 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2013
The Corsica site has been established in 1996 to perform altimeter calibration on TOPEX/Poseidon and then on its successors Jason-1 and Jason-2. The first chosen location was under the #85 ground track that overflight the Senetosa Cape. In 2005, it was decided to develop another location close to Ajaccio, to be able to perform the calibration of Envisat and in a next future of SARAL/AltiKa that will flight over the same ground tracks. Equipped with various instruments (tide gauges, permanent GPS, GPS buoy, weather station…) the Corsica calibration site is able to quantify the altimeter Sea Surface Height bias but also to give an input on the origin of this bias (range, corrections, orbits, …). Due to the size of Corsica (not a tiny island), the altimeter measurement system (range and corrections) can be contaminated by land. The aim of this paper is to evaluate this land contamination by using GPS measurements from a fixed receiver on land and from another receiver onboard a life buoy. Concerning the altimeter land contamination, we have quantify that this effect can reach 8 mm/km and then affects the Sea Surface Height bias values already published in the framework of the Corsica calibration site by 5–8 mm for TOPEX and Jason missions. On the other hand, the radiometer measurements (wet troposphere correction) are also sensitive to land and we have been able to quantify the level of improvement of a dedicated coastal algorithm that reconciles our results with those coming from other calibration sites. Finally, we have also shown that the standard deviation of the GPS buoy sea level measurements is highly correlated (∼87%) with the Significant Wave Height derived from the altimeters and can be used to validate such parameter. 相似文献
102.
传统的夹芯结构复合材料通常是将面板和芯材粘结在一起,这使得夹芯结构芯材与面板的界面性能薄弱.为了弥补现有夹芯结构材料界面性能薄弱的缺点,研究了缝纫增强泡沫夹芯结构复合材料一体化成型工艺,并对其力学性能进行了试验研究.通过与未缝纫泡沫夹芯结构的对比试验,发现缝纫能显著提高泡沫夹芯结构的弯曲强度、平压强度和侧压强度,而且随着缝纫密度的增加,该夹芯结构的抗弯、平压和侧压性能均有提高. 相似文献
103.
崔海涛%温卫东%佟丽莉 《宇航材料工艺》2003,33(6):39-42
基于ANSYS有限元分析软件,利用其中的层合板单元,对纤维缠绕复合材料弯管的强度进行分析,并进一步预测了弯管的破坏压力。通过与试验结果的对比,验证了分析模型和分析方法的有效性,为分析纤维缠绕弯管结构的强度提供了一种有效的途径。 相似文献
104.
Development of PLC-based Tension Control System 总被引:1,自引:0,他引:1
REN Sheng-le LU Hua WANG Yong-zhang FU Hong-ya 《中国航空学报》2007,20(3):266-271
Fiber winding tension is an important factor in the molding techniques of composite material which influences the quality of winding product directly, and the tension control is a key technique in fiber winding techniques. This paper introduces a closed-loop tension control system with the programmable logic controller (PLC) with function modules as its control kernel, the alternating current (AC) servo motor as execute element and the radius-following device to accomplish the real-time radius compensation. The mechanism of the tension control system is analyzed and the numerical model is set up. The compensation technique of the radius of the scroll is analyzed. Experimental results show that the system is well qualified with high control precision and high reaction speed. 相似文献
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介绍了64点导电环塑料组环座方案的选择、注射模的设计要素及模具型芯中64条环形槽的加工方案。使用表明,该导电环塑料组环的各项指标均符合产品使用要求。 相似文献
107.
对某缠绕壳体芯模形制的选择及芯模成型工装的设计进行了分析和探讨,提出了金属骨架石膏面层可拆卸芯模成型设计方案。通过对芯模金属骨架和刮刀的精心设计,重点考虑芯模骨架组装和可拆卸以及装配制造精度,解决了石膏芯模刮制成型技术问题,实现了缠绕壳体内型面及尺寸的精确控制。 相似文献
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