GPS变形监测平差计算及不确定度分析

全球定位系统（GPS）是一种全天候、高精度的连续定位系统，它以速度快、方法灵活多样、操作简便等优势被广泛应用于工程测量和变形监测中。结合水厂铁矿GPS边坡变形监测实例，对GPS监测网的星历预报、基线向量平差计算、网平差计算、结果及残差不确定度进行了细致分析研究，以验证GPS技术在边坡变形监测中的可靠性和精度。

编队飞行GPS/INS相对导航的分布滤波算法

在对编队飞行GPS/INS相对导航当前的主要滤波算法进行总结和分析的基础上,提出了分布滤波的算法,并建立了GPS/INS相对导航仿真系统,对该算法进行验证。仿真结果表明该算法能够适应大型、紧密编队飞行的需求,在减小计算量、降低通讯数据量、允许编队做大的机动飞行的同时,能得到较高的估计精度。

A 5.6-mW Power Dissipation CMOS Frequency Synthesizer for L1/L2 Dual-Band GPS Application

This paper presents a wide tuning range CMOS frequency synthesizer for dual-band GPS receiver, which has been fabricated in a standard 0.18-um RF CMOS process. With a high Q on-chip inductor, the wide-band VCO shows a tuning range from 2 to 3.6GHz to cover 2.45GHz and 3.14GHz in case of process corner or temperature variation, with a current consumption varying accordingly from 0.8mA to 0.4mA, from a 1.8V supply voltage. The measurement results show that the whole frequency synthesizer costs a very low power consumption of 5.6mW working at L I band with in-band phase noise less than -82dBc/Hz and out-of-band phase noise about -112 dBc/Hz at 1MHz offset from a 3.142GHz carrier.

一种提高车载单频GPS实时定位精度的方法

民用单频GPS接收机实时定位精度约为 1 0 0m。将民用单频GPS接收机装载到汽车上进行导航工作，如不用差分等方法，则其实时定位精度也只能为 1 0 0m。假设在车上另加测向测距装置，以此为基础，提出一种提高车载单频GPS接收机实时定位精度的算法。

高精度GPS,三维激光扫描和测针板三种测量技术监测沟蚀过程的对比研究

采用连续模拟降雨试验,对坡沟系统概化模型进行坡面沟蚀发育过程模拟,再现坡面片蚀—细沟侵蚀—切沟侵蚀演变过程。结合3种测量技术从测量精度、测量人员要求、数据处理、数据通用性、配套软件使用、前期投入、测量条件等几个方面入手,对比分析高精度GPS(Trimble 5700)、三维激光扫描仪(Leica HDS 3000)和测针板的3种测量方法的优缺点,同时对3种测量方法在沟蚀过程监测和侵蚀量估算方面进行对比研究。结果表明,激光扫描仪能很好地监测沟蚀演变过程,且对侵蚀量估算精度较高,误差仅为4.5%。高精度GPS也能很好地监测沟蚀演变过程,对侵蚀量估算精度误差为7.38%。测针板法不能很好的反映沟蚀演变过程,但是对于侵蚀量的估算可以满足日常要求,误差为-12.78%。

A Low Power Dissipation Wide-Band CMOS Frequency Synthesizer for a Dual-Band GPS Receiver

This paper presents a wide tuning range CMOS frequency synthesizer for a dual-band GPS receiver,which has been fabricated in a standard 0.18μm RF CMOS process. With a high Q on-chip inductor, the wide-band VCO shows a tuning range from 2 to 3.6GHz to cover 2.45 and 3.14GHz in case of process corner or temperature variation,with a current consumption varying accordingly from 0.8 to 0.4mA,from a 1.8V supply voltage. Measurement results show that the whole frequency synthesizer consumes very low power of 5.6mW working at L1 band with in-band phase noise less than - 82dBc/Hz and out-of-band phase noise about - ll2dBc/Hz at 1MHz offset from a 3. 142GHz carrier. The performance of the frequency synthesizer meets the requirements of GPS applications very well.