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171.
Evaluation of ENVISAT ASAR data for sea surface wind retrieval in Hong Kong coastal waters of China 总被引:2,自引:1,他引:1
The C-band wind speed retrieval models, CMOD4, CMOD - IFR2, and CMOD5 were applied to retrieval of sea surface wind speeds from ENVISAT (European environmental satellite) ASAR (advanced synthetic aperture radar) data in the coastal waters near Hong Kong during a period from October 2005 to July 2007. The retrieved wind speeds are evaluated by comparing with buoy measurements and the QuikSCAT (quick scatterometer) wind products. The results show that the CMOD4 model gives the best performance at wind speeds lower than 15 m/s. The correlation coefficients with buoy and QuikSCAT winds are 0.781 and 0.896, respectively. The root mean square errors are the same 1.74 m/s. Namely, the CMOD4 model is the best one for sea surface wind speed retrieval from ASAR data in the coastal waters near Hong Kong. 相似文献
172.
Tidal flow past a headland was modelled and the resulting sandbank formation due to bedload transport by eddy systems was examined with particular emphasis on the role of Coriolis. The headland configuration was extended to the more complex case of a headland with a detached island and the role of Coriolis in sandbank formation was again examined. In the headland case, the contribution of Coriolis resulted in the expected change in bed level at the centre of the residual eddies (positive contribution for the cyclonic eddy and negative change for the anticyclonic eddy). In the headland/island case, the role of Coriolis in the resulting bed level change was a function of eddy shedding from the island, defined by the island wake parameter. When eddy shedding occurred, the inclusion of Coriolis had a large magnitude effect on creating flood/ebb sandbank asymmetry. When eddies remained attached to the island, Coriolis had a minor role in the magnitude of this asymmetry. 相似文献
173.
The drilling parameter monitor is an important tool in drilling engineering applied to monitoring drilling process, carrying out scientific analysis and decision-making. Based on discussing the present development situation of the domestic and foreign drilling machine parameter monitors, the metering scheme for vehicle-loaded drilling parameter monitor was designed. By using detection system for MSP430 single-chip microcomputer (SCM) in combination with peripheral circuit such as sensors, the drilling-rig control system was obtained to detect, and for every parameter in real-time display in order to keep operating the drilling rig status. The experiment shows that the drilling parameter monitor reaches design requirements and can be applied to drilling engineering monitoring, which has characters such as simple structure, high credibility and low cost. 相似文献
174.
175.
We investigated and compared the pattern of accumulation of recent and late atretic follicles in the ovaries of Iberian sardine, Sardina pilchardus, in relation to body size with the aim to examine whether late atresia can be used in back-calculations of individual spawning history. Oppositely to earlier stages, late atresia in sardine was shown to accumulate even at peak spawning periods in fish of larger size/age indicating a relationship between atretic intensity and the distant reproductive performance of the individuals. Despite the fact that intensity of late atresia was very high in some occasions, its accumulation was not shown to impede imminent spawning activity. Lack of dependence between imminent spawning activity and the intensity of late atresia was related to the differential pattern with which postovulatory and atretic follicles are associated to the lamellar epithelium of the ovary. Finally, the effect of the ‘reference trap’ which is a major source of bias when quantifying structures in stereological measurements, could be mediated or even completely removed by using a measure of ovarian growth, such as gonosomatic index in the present study, as a covariate when modeling variability in the intensity of atresia. 相似文献
176.
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???????RTK-GPS(????????λ??)???????????????????????????????????????????????????????RTK-GPS???????????????????????????????????????????????????????????е?? 相似文献
177.
???????????????????????????????????????嶫?????????GPS????????????????????????????????λ??ó?????????β???????仯???????????2001???????8.1???????????β?????????д?????μ?仯????????仯?????????ж??????????С????????????????????????????????????????8.1????????????????????????????????о????????????????β???????п??????????????????? 相似文献
178.
��ά�ռ����ά�ռ��߲���ת����������·��� 总被引:6,自引:1,他引:5
????????????δ?????????????????????????????????·?????????????????????????????????????????????????????????÷?Χ???ó?????:????γ??????Χ??С??8???,??x??y???????????????1 cm??????????侫???????γ??(?????γ??)??Χ????С?????????? 相似文献
179.
180.
高速公路接线处中线偏差的一个特殊处理案例 总被引:1,自引:1,他引:0
喻雄 《测绘与空间地理信息》2009,32(1)
笔者结合高速公路勘测设计中的实践,介绍高速公路接线处中线偏差的处理及调整方法,介绍了其在AutoCAD中处理的一个例子. 相似文献