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161.
Precise aircraft single-point positioning using GPS post-mission orbits and satellite clock corrections 总被引:3,自引:0,他引:3
Summary Aircraft single point position accuracy is assessed through a comparison of the single point coordinates with corresponding DGPS-derived coordinates. The platform utilized for this evaluation is a Naval Air Warfare Center P-3 Orion aircraft. Data was collected over a period of about 40 hours, spread over six days, off Florida's East Coast in July 94, using DGPS reference stations in Jacksonville, FL, and Warminster, PA. The analysis of results shows that the consistency between aircraft single point and DGPS coordinates obtained in single point positioning mode and DGPS mode is about 1 m (rms) in latitude and longitude, and 2 m (rms) in height, with instantaneous errors of up to a few metres due to the effect of the ionosphere on the single point L1 solutions. 相似文献
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邱国荣 《地震地磁观测与研究》1992,13(2):61-66
文章根据长周期地震观测的理论和我国763长周期台网的观测实践,分析了长周期观测中的环境干扰。认为长周期观测对环境干扰(主要指温、湿度)敏感,但影响长周期仪器正常工作的关键是潮湿,尤其是记录室的潮湿。文章以763台网优秀台站的观测实践为例,认为只要掌握了环境干扰的规律,在防潮问题上采取有效措施,长周期地震观测是完全可以做到仪器工作稳定,管理得心应手。 相似文献
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内蒙红花沟金矿床同位素地质特征及矿床成因探讨 总被引:4,自引:0,他引:4
通过对红花沟金矿床主要岩类及金矿石的氧、氢、铅、钾-氩和铷锶同位素的测定,研究了该矿的同位素地球化学特征,探讨了成矿物质来源、成矿时代、成矿温度等矿床成因问题。认为成矿物质来自建平群变质岩,元古宙钾长花岗岩的成岩作用使金活化迁出而成矿。成矿热液以岩浆水为主,并有部分大气降水混入,成矿温度为250~350℃。 相似文献
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近年来湖南省在地勘行业管理上开展了法规法制建设、规划计划编制、勘查秩序维护、勘查成果管理、勘查外部环境改善等方面的工作,“八五”后3年继续开展法制建设、勘查登记管理、勘查成果管理、建立行业统计系统、做好服务协调工作,推广改革经验等。 相似文献
169.
In situ measurements of stratospheric H2SO4 and HSO3vapors using passive chemical ionization mass spectrometry were made in October 1982 after the eruption of volcano El Chichon. Data were obtained between about 20 and 41 km showing [H2SO4 + HSO3] sum concentrations between about 104 and 2 × 105 cm?3 below 29 km and a steep rise above this altitude. Maximum [H2SO4 + HSO3] values of about 3 × 106 cm?3 are reached above 35 km.Partial [HSO3] concentrations increase above 34 km reaching about around 40 km. From the measurements it is concluded that H2SO4 and probably HSO3photolysis have an important influence above 34 km leading to the observed increase of [HSO3] and a depletion of H2SO4vapor.It also seems that the data support the view of heterogeneous HSO3 removal. If correct, this would imply that stratospheric aerosols are formed primarily from HSO3 rather than H2SO4vapor. 相似文献
170.
Radium-226 (226Ra) activities were measured in the surface water samples collected from the Arctic Ocean and the Bering Sea during the First
Chinese National Arctic Research Expedition. The results showed that 226Ra concentrations in the surface water ranged from 0.28 to 1.56 Bq/m3 with an average of 0.76 Bq/m3 in the Arctic Ocean, and from 0.25 to 1.26 Bq/m3 with an average of 0.71 Bq/m3 in the Bering Sea. The values were obviously lower than those from open oceans in middle and low latitudes, indicating that
the study area may be partly influenced by sea ice meltwater. In the Bering Sea, 226Ra in the surface water decreased northward, probably as a result of the exchange between the 226Ra-deficient sea ice meltwater and the 226Ra-rich Pacific water. In the Arctic Ocean, 226Ra in the surface water increased northward and eastward. This spatial distribution of 226Ra reflected the variation of the 226Ra-enriched river component in the water mass of the Arctic Ocean. The vertical profiles of 226Ra in the Canadian Basin showed a concentration maximum at 200 m, which could be attributed to the inputs of the Pacific water
or/and the bottom shelf water with high 226Ra concentration. This conclusion was consistent with the results from 2H, 18O tracers. 相似文献