共查询到14条相似文献,搜索用时 62 毫秒
1.
2.
为进一步规范"二级检查、一级验收"制度,提高作业单位对自身资料潜在质量问题的预判能力,提升海洋测量成果验收的工作效率和成果优秀率,指出:各级业务部门应从两方面对海底地形测量数字测深成果开展质量检查并留存全过程记录,一是构建交叉点不符值数列并基于内、外精度指标作量化表征;二是生成多维、多类型海底地形曲面并在位置交叉域作直观拼接。针对成果水深在深度方向的异构性提出了基于水位改正逆过程的解决方法,多角度展示了《海洋测量信息处理工程》水深数据处理与成图软件中数字测深成果基于测深点、线、面的多样化拼接检查功能。 相似文献
3.
4.
海洋测量中的交叉点误差反应了测量的误差信息,交叉点误差分析是海洋测量数据处理的重要环节。首先对可能引起交叉点误差的误差源进行了分析,然后讨论了从交叉点误差分析中可能提取的信息,最后对数据连续化过程中交叉点的定位与交叉点误差的确定进行详细分析。研究发现在进行数据连续化以定位交叉点的过程中,交叉点处测量值的误差特性将不同于原始测量值的误差特性,而且不同交叉点误差之间可能存在相关性。导出了交叉点误差方差以及不同交叉点误差间协方差的公式,从而能够求得交叉点误差向量的方差协方差矩阵,该矩阵在后续的平差处理中具有重要作用。 相似文献
5.
6.
7.
8.
9.
Angelika Brandt Katrin Linse Myriam Schüller 《Deep Sea Research Part I: Oceanographic Research Papers》2009,56(11):2013-2025
The aim of this study is to compare the depth distributions of four major Southern Ocean macrobenthic epi- and infaunal taxa, the Bivalvia, Gastropoda, Isopoda, and Polychaeta, from subtidal to abyssal depth. All literature data up to summer 2008, as well as the unpublished data from the most recent ANDEEP I–III (Antarctic benthic deep-sea biodiversity: colonisation history and recent community patterns) expeditions to the Southern Ocean deep sea are included in the analysis. Benthic invertebrates in the Southern Ocean are known for their wide bathymetric ranges. We analysed the distributions of four of the most abundant and species-rich taxa from intertidal to abyssal (5200 m) depths in depth zones of 100 m. The depth distributions of three macrofaunal classes (Bivalvia, Gastropoda, Polychaeta) and one order (Isopoda) showed distinct differences. In the case of bivalves, gastropods and polychaetes, the number of species per depth zone decreased from the shelf to the slope at around 1000 m depth and then showed stable low numbers. The isopods showed the opposite trend; they were less species rich in the upper 1000 m but increased in species numbers from the slope to bathyal and abyssal depths. Depth ranges of families of the studied taxa (Bivalvia: 31 families, Gastropoda: 60, Isopoda: 32, and Polychaeta: 46 families) were compiled and illustrated. At present vast areas of the deep sea in the Southern Ocean remain unexplored and species accumulation curves showed that only a fraction of the species have been discovered to date. We anticipate that further investigations will greatly increase the number of species known in the Southern Ocean deep sea. 相似文献
10.
The “C-Plane” is a submerged variable depth ocean current turbine that is tethered to the sea floor and uses sustained ocean currents to produce electricity. As part of the development of a th scale physical model of the C-Plane, a mathematical model and dynamics simulation of the prototype was developed and is presented in this paper. This three-dimensional mathematical model represents the C-Plane as a rigid body with moveable control surfaces that is moored with three linear elastic cable elements. Gravitational, buoyancy, hydrodynamic, cable, gyroscopic, and inertial forces are included and a PC-based dynamics simulation is created. The simulation demonstrates that the C-Plane is stable and capable of changing depth in all expected operating conditions. The C-Plane prototype can fly level from a height of 3 to 6 m using the configuration suggested in this paper. The maximum ascent rates of the C-Plane with a water speed of 0.3 m/s are 0.015 m/s when the pitch is fixed at 0° and 0.030 m/s when the pitch is fixed at 4°. The maximum descent rates of the C-Plane are 0.018 m/s when the pitch is held at 0° and 0.031 m/s if the pitch is held at −4°. 相似文献
11.
Major sequence boundaries associated with eustatic sea level changes are correlated to the general stratigraphy of the north-eastern Gulf of Mexico. The details of a Middle Cretaceous Flooding Surface, marking a major break in sedimentation, are documented. The sequence stratigraphic work provides an example of the ‘stratigraphic signature of the Neogene’. Three major episodes of sediment accumulation are represented by: (1) Late Jurassic (150.5 Ma) to Middle Cretaceous (94 Ma) aggradation and progradation of sediments with significant sediment accumulation in the present shelf and slope areas; (2) an extended period of starved sedimentation during 94-30 Ma corresponding to Middle Cretaceous flooding events (93.5 and 91.5 Ma) and the lack of sediment supply; and (3) since Late Oligocene time, unusually rapid sedimentation rates that characterize the deep water study area. These patterns of sediment accumulation directly affect the formation of allochthonous salt in the study area. 相似文献
12.
In the context of the sea level survey at the mm level, it is necessary all along the lifetime of the altimeter mission to survey the quality of the products from the microwave radiometer. The calibration of the brightness temperatures has been validated using reference brightness temperatures over selected continental areas as well as simulations for a wide range of oceanic and atmospheric situations. The validation of the wet path delay is performed by comparison with radiosonde measurements and pointed out that both the JMR and the TMR estimate wet path delay around 5 mm higher than the one measured by radiosondes. Furthermore, it appeared that the correction of the TMR drift degrades the product with respect to radiosonde measurements. The monitoring of the brightness temperatures since launch shows a mean drift around +0.1 K/year for the 18.7 GHz, ?0.6 K/year for the 23.8 GHz channel, and around ?0.4 K/year for the 34 GHz channel. 相似文献
13.
In the context of the sea level survey at the mm level, it is necessary all along the lifetime of the altimeter mission to survey the quality of the products from the microwave radiometer. The calibration of the brightness temperatures has been validated using reference brightness temperatures over selected continental areas as well as simulations for a wide range of oceanic and atmospheric situations. The validation of the wet path delay is performed by comparison with radiosonde measurements and pointed out that both the JMR and the TMR estimate wet path delay around 5 mm higher than the one measured by radiosondes. Furthermore, it appeared that the correction of the TMR drift degrades the product with respect to radiosonde measurements. The monitoring of the brightness temperatures since launch shows a mean drift around +0.1 K/year for the 18.7 GHz, -0.6 K/year for the 23.8 GHz channel, and around -0.4 K/year for the 34 GHz channel. 相似文献
14.
《Ocean Modelling》2008,20(3):207-222
Free oscillations in the period range from 9 to 40 h and their corresponding adjoint solutions are used to synthesize semidiurnal and diurnal tides of second degree. The free oscillations are determined with explicit consideration of frictional terms and the full loading and self-attraction effect. This allows for a detailed analysis of the loading and self-attraction effect on the dynamics of ocean tides, e.g. a physical explanation is given for the induced phase delay computed by ocean tide models.Further, the synthesis gives a spectral composition of certain well known tidal features and pairs of free oscillations are identified, diminishing their contribution either on a global or local scale. 相似文献