共查询到19条相似文献，搜索用时 109 毫秒
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卫星测高在确定地球重力场中的应用 总被引：2，自引：1，他引：2
根据测高所得的几何量与地球重力场物理量之间的关系，探讨了卫星测高数据在确定地球重力场参数中的应用，主要包括利用卫星测高数据确定海洋大地水准面、确定海洋重力异常和改善地球重力场模型。 相似文献
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褶皱臂尾轮虫(Brachionus plicatilis)是轮虫动物门(Rotifera)中的广盐种。其个体微小、培养容易、营养丰富,是目前唯一能够在海水养殖中进行大规模培养,并用于海产动物人工育苗的物种。褶皱臂尾轮虫生活史为孤雌生殖和有性生殖世代交替进行,是生物学研究的模型生物。本研究用FIASCO法构建了褶皱臂尾轮虫微卫星富集文库,分离了135个微卫星;用PCR-PAGE分型法分析山东半岛褶皱臂尾轮虫群体,获得8个多态微卫星。等位基因数2~4个;观测杂合度和期望杂合度范围分别为0.1471~0.6364和0.3139~0.6559;遗传偏离指数为-0.3624~0.05353;多态信息含量为0.2615~0.5841。无微卫星偏离哈温平衡,但有2个微卫星处于连锁不平衡。本研究筛选的8个微卫星为褶皱臂尾轮虫遗传多样性和种群结构分析提供了标记。 相似文献
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van Ballegooijen E.C. van Mierlo G.W.M. van Schooneveld C. van der Zalm P.P.M. Parsons A.T. Field N.H. 《Oceanic Engineering, IEEE Journal of》1989,14(4):375-383
A practical method is described for the three-dimensional determination of the position, shape, and attitude of a hydrophone array towed from a surface vessel. It provides successive snapshots of the array configuration with a maximum rate of about three per minute. The method is intended as an alternative to the use of fixed test ranges and provides results suitable for validating computer models of array motion. It uses the travel-time differences of impulsive waves measured across the array. The waves are generated by two explosive charges dropped from consorts. Results of a typical experiment are presented as an illustrative example. The array position relative to the tow ship is obtained to within an accuracy of a few metres 相似文献
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A four‐antenna GPS attitude determination system was used to estimate roll, pitch, and heading parameters of a 52‐meter surveying vessel in an operational marine environment. The least squares algorithm for platform attitude estimation using multiple baseline vector observables is presented. An efficient on‐the‐fly carrier phase ambiguity searching method is derived, which utilizes the Cholesky decomposition method and the known baseline constraints between the GPS antennas to construct the potential ambiguity sets on the sphere. The accuracy of the estimated attitude parameters from the GPS multi‐antenna system was assessed with an independent inertial navigation system (INS). Results from sea trials show that the proposed GPS multi‐antenna system and processing algorithms delivered a satisfactory performance under various ship maneuvers. The accuracy of GPS estimated ship attitude parameters is better than 0.06 degrees at an output rate of 10 Hz. Such a performance demonstrates a new alternative means to provide accurate, reliable, and cost‐effective ship attitude information for hydrographic applications. 相似文献
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利用2016年6月17日~7月18日期间北斗卫星导航系统IGSO-6卫星相关数据,针对IGSO-6卫星的单星服务性能和对系统的服务性能影响以及新姿态控制模式对轨道确定的影响三个方面进行分析评估。分析结果表明,IGSO-6卫星空间信号用户测距误差为1.85m,卫星钟天稳定度为10-14量级,准确度为10-11量级,天漂移率接近10-13量级;新卫星的加入提升了系统服务性能,不同区域提升程度不同,PDOP最大提升20%左右;新姿态控制模式有助于改善地影期卫星精密轨道确定。 相似文献
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目前业内普遍使用的机械式海流计功耗大,连续工作时间短,姿态测量精度较低,体积较大,存储容量较小,维护复杂,在需要长时间进行海洋观测使用时十分不便。针对这一实际问题,为提高海流计的性能,设计以STM32f103ZE处理器为核心,运用现代锂离子电池技术,存储技术,传感器技术,无线充电技术,无线通信技术,对机械式海流计电子电路进行了重新设计。样机测试结果表明:该设计功耗低,流向精度高,维护简单且可长时间在水下稳定工作,完全满足各种海洋作业中海流测量需求,具有很大的实用价值。 相似文献
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多波束测深系统作业的基本前提是测船保持匀速直线运动状态,而实际作业中非匀速运动状态下的多波束测量普遍存在,此时常用的基于加速度测量原理的测姿设备会受到影响。为此,在多波束测姿误差分析的基础上,针对直线加速、U型转弯两种情况下的测姿误差进行研究,通过INS测姿与GNSS三天线测姿的数据比较,对非匀速直线运动状态下姿态误差的影响特点及程度进行了分析。实验证明当测船做直线加速运动时,会使纵摇角产生较大误差;当测船转弯时,会使横摇角产生较大误差,这对指导多波束实际测量具有一定的参考价值。 相似文献
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Abstract The paper describes a general mathematical model for the determination of depths, using “stereoscopic”; Side Scan Sonar images. It is based on the assumption that the attitude and position parameters of the sensor can be continuously recorded or reconstructed by calculation. 相似文献
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Shipborne GPS attitude determination during MMST-93 总被引：1，自引：0，他引：1
Lachapelle G. Cannon M.E. Lu G. Loncarevic B. 《Oceanic Engineering, IEEE Journal of》1996,21(1):100-104
The attitude parameters of a ship underway were measured using a configuration of four 10-channel NovAtel Model 951 narrow-correlator-spacing receivers. These C/A code receivers have output rates of up to 10 Hz and maintain effective carrier phase lock under relatively harsh ship dynamics. The attitude parameters are calculated independently at each epoch using differential carrier phase measurements, carrier phase ambiguities are resolved on-the-fly by constraining the approximately known distances between the antennas that are rigidly mounted on the ship. Carrier phase thermal noise and multipath are minimized by mounting the antennas as far apart as possible. The four-antenna configuration provides redundancy and further improves accuracy. During the Matthew Motion Sensor Trials (MMST-93) conducted off the coast of Halifax, Nova Scotia, in June-July 1993, the GPS-derived attitude parameters were compared with those obtained with a Honeywell HG1050 ring laser gyro inertial navigation system (INS) which provides roll and pitch with an accuracy of 15 arcsecs and heading with an accuracy of 2 arcmins. To simulate rough weather conditions, sharp maneuvers were performed to induce roll angles in excess of 10°. No accuracy degradation nor any loss of GPS measurements occurred. The RMS agreement between GPS and INS derived attitude parameters is better than 2 arcmins in heading, 1 arcmin in pitch and 3 arcmins in roll. This level of accuracy demonstrates the capability of GPS for cost-effective shipborne attitude determination at an accuracy level of 0.05 相似文献