查询词典 GPS

Error sources of velocity estimate have been changed since SA was off. Firstly influence quantities of all kinds of error sources of velocity determination were analyzed, the potential accuracy of GPS absolute velocity estimate was derived from both theory and field GPS data simulation.

首先从理论和实测数据模拟两方面分析了SA取消后各类误差源对GPS测速的影响，推导并计算了GPS单点测速可能达到的精度水平。

The quality of the initial fields of the numerical model and the accurateness of the precipitation forecast are both improved. How to obtain and assimilate the GPS bending angle are studied and realized.

介绍了如何获得GPS折射角资料的原理，研究了对GPS折射角资料的同化方法，实现了对GPS折射角资料的同化。

The heading determination model based on two total positioning systemis used to calibrate the ship alongshore heading together with the GPS attitude determination equipment, time synchronization system via receiving GPS second pulse to synchronize the two kinds of data is also designed.

结合GPS姿态测量设备，通过采用数据插值融合技术，进行舰船组合航向测量。为了提高组合航向测量的精度，设计了通过接收GPS秒脉冲对两种航向测量数据进行时间同步的系统。

The research work discussed in this dissertation aims to image time-dependent 3-D distribution of ionospheric electron density, Ne, in the region to be recovered from the combination of ground-based GPS network measurements and GPS beacon observations obtained by a receiver on board of Low Earth Orbit satellite when the GPS satellite is occulted by the surface of the Earth as seen by the receiver.

比如，结合地基GPS与掩星观测的时变三维电离层层析成像数学上的重建公式尚未建立，由GPS地面台网观测和低轨卫星获得的掩星观测数据实现时变三维电离层层析的反演算法和计算机程序有待发展等等。

In this research we increased the backsights from 3 to 10 points.and observed 5 sets of VRS,1 set of static GPS,5 sets of 3D LASER. we considered the Static GPS as the standard observation set,and compared it with the VRS's coordinates after adjustment.The RMS and the range of differences are taken as the indicator of accuracy .

一般而言，3D LASER作业只须三个已知点即可定得绝对坐标，为了增加多余观测量，本研究将3个后视点增加为10个后视点，针对这10个后视点分别施测5组VRS、1组静态GPS、及5组3D LASER，文中以静态GPS为对照组，以改正前后之VRS坐标与静态GPS坐标较差之RMS及分布范围为精度分析之指标。

Muti antennae GPS/Gyro integrated navigation system is studied too in this paper. Using single difference GPS carrier phase observations and quaternion error, state equation and measurement equation is established for muti antennae GPS/Gyro integrated navigation system.

本文也对多天线GPS/Gyro组合捷联航姿系统进行了研究，利用单差载波相位测量的方法，建立了基于四元数误差的多天线GPS与Gyro组合航姿系统的状态方程和量测方程。

10 P.m.-- When I bypass the last watchtower which is 700m from the confluence, I excitement rush down the hill, holding the GPS, and headed out to the spot, I was too busy to say hello to the local rustics who were ingathering potatoes on the hillside, following the GPS pointer from 200, 100, 70,20, at the spot even showed within 1 m, I succeed hunting my first confluence.

5：10 p.m。--当我绕过最后一个距汇交点最近的烽火台时，GPS显示汇交点就在距此偏西北700多米的距离了。我兴奋地冲下山直奔它，山坡上农民正在收获土豆，我已顾不上和他们打招呼，手持GPS直奔那点，GPS也迅速显示距该点从200，100，70，20，到最后竟然闪过精度不到1米，我成功了。

In order to solve the heavy workload and the low efficiency of the train maneuver, one kind of train security alarm system based on GPS and INS technique was presented. The Kalman filter used in the information fusion of GPS and ISN was analyzed, solving the problem of the infinite position error of an INS and the slow modification rate of a GPS. By using the original train database to correct the mileage, the precision of the system was improved.

为了弥补目前火车车辆运行中人工统计调度工作量大、效率低等缺陷，提出了一种基于全球定位系统和惯性导航技术的火车安全告警系统的设计方案；重点讨论了GPS/INS在信息融合时所使用的卡尔曼滤波方法，避免了独立的惯性导航系统无限位置误差和GPS的1 Hz慢速数据修正的问题；利用原有国家铁路网数据库进行数据修正，进一步提高了系统的精度。

a system of along-track mode sar based on the gps is established.by seeing the gps signal as a chirp,chirp scaling algorithm of this mode with large squint angle is investigated.chirp scaling algorithm is considered more efficient and widely applicable when the bistatic sar system is in side-look or small squint angle mode,but in large squint angle case,the errors caused by taylor expansion are so large that the algorithm could lose its precision.in such a case,an equivalent mono-static sar range mode which has fewer errors than taylor expansion with large squint angle is proposed to substitute the range history of bistatic sar.then bistatic sar images with large squint angles are gotten by common nonlinear cs algorithm.the effectivity of the method is verified by matlab simulation.

摘 要：建立了基于gps的顺轨sar系统模型，通过将gps信号等效为chirp信号，研究了在该模式下的大斜视角chirp scaling算法。在正侧视或小斜视情况下，cs算法具有较好的聚焦性能和广泛的适用性，但在斜视角较大的情况下，该算法将散焦而不能成像，因而提出了用等效的单基地距离模型来代替双基地距离历史的方法，解决了大斜视角情况下距离模型二阶近似误差较大的问题，并结合单基地非线性cs算法，实现了在大斜视角情况下的基于gps反射信号的双基地sar高精度成像，最后通过matlab仿真进行了验证。

Furthermore, they continuously transmit radio signals of low power and ultra high frequency. They are also equipped with atomic clocks. When GPS receivers intend to calculate its GPS position on the earth, they will receive the signals from satellites, calculate transmission time with a pre-stored ephemeri, and then calculate the distances between themselves and at least four GPS satellites with the method of trilateration.

所有的卫星架有原子钟，当GPS接收器要找出自己目前在地球表面上的位置时，会接收各卫星的讯号，并依储存的星历表计算传送时间，再利用三边测量法订出自己与至少四颗GPS卫星之间的精确距离，即可算出所在位置。

If you are unfortunate enough to the lovelorn, please tell me, I will help you out, really, please contact me!

如果你不幸失恋了，请告诉我，我会帮助你摆脱困境，真的，请联系我啦！

China's plan to cut energy intensity by 20 percent and pollutant discharges by 10 percent between 2006 and 2010 is a case in point.

中国计划在2006年到2010间降低20%的能源强度和减少10%的主要污染物排放，就是一个这样的例子。