基于C++Builder的天测罗经差算法研究

利用《航海天文历》查表的方法来获得罗经差的计算过程比较复杂.基于C Builder语言编程,根据观测太阳测定罗经差的计算公式,提出了一种新型的天测罗经差算法.以某舰实测数据为基础,进行计算机仿真,结果表明该方法克服了传统的查表法计算繁琐、不能满足实时定位的缺点,提高了计算效率和计算精度,具有一定的可行性.     

高精度手持式多功能人眼安全激光测距仪

研制的手持式多功能人眼安全激光测距仪,集成了数字罗盘、GPS、白光瞄准通道、人眼安全激光测距组件、低功耗微显示器等功能模块,具备方位角／俯仰角测量、地理经纬度测量、可见光目视观察、激光测距、分划线夜间照明、综合信息集成显示和输出等功能,经过外场测试,整机作用距离达到10km,测距精度2m,方位角／俯仰角精度0．5°,定位精度CEP值为10m,满足设计要求。     

基于地磁测向和时间到达差测距的行人航迹推算方法

为研究个人鞋式导航定位方法,提出了一种基于地磁测向和时间到达差测距的行人航迹推算方法。该方法分为两部分:依靠地磁辅助的航向角检测和依靠时间到达差测距的行人步幅检测。研究结果发现,采用超声波收发阵列可以有效提高两脚间距离检测精度。此外本文分析出该方法的主要误差来源为航向角检测误差,并设计了最小二乘误差补偿算法,补偿前航向角误差约为15.93°,补偿后在0.435°以内。实验通过行人直线、圆形、操场行走测试,结果表明最大定位误差占总行进距离的1.2%。本方法具有广泛的工程应用前景。     

Dynamic Mg2B8 Cluster: A Nanoscale Compass

Boron‐based binary cluster Mg₂B₈ is shown to adopt a compass‐like structure via computational global searches, featuring an Mg₂ dimer as the needle and a disk‐shaped B₈ molecular wheel as baseplate. The nanocompass has a diameter of 0.35 nm. Born–Oppenheimer molecular dynamics simulations indicate that Mg₂B₈ is structurally fluxional with the needle rotating freely on the baseplate, analogous to a functioning compass. The dynamics is readily initiated via a ultrasoft vibrational mode. The rotational barrier is only 0.1 kcal mol⁻¹ at the single‐point CCSD(T) level. Chemical bonding analysis suggests that the cluster compass can be formulated as [Mg₂]²⁺[B₈]²⁻; that is, the baseplate and the needle are held together primarily through ionic interactions. The baseplate is doubly aromatic with π and σ sextets. The bonding pattern provides a dilute, continuous, and delocalized electron cloud, which underlies the dynamics of the nanocompass.     

基于GPS辅助以实现捷联式数字磁罗经自动消差的研究

针对目前使用的磁罗经体积重量大,消差操作依赖人工进行的不足,提出一种能够自动测校误差的数字式磁罗经系统。利用椭圆假设求解数字磁罗经的自差及相应的误差补偿方法,同时基于GPS信号的辅助,将船舶位置信息引入描述地球地磁磁差的八阶泰勒多项式中,得到在不同位置时的磁差修正值。然后经过计算机处理求得真实航向,完成对数字磁罗经的自动消差。     

利用磁聚焦法测量地磁场

利用电子比荷测试仪,借助罗盘、水平仪和铅垂等简单工具,分别测量进行磁聚焦后正、反向两次通过的励磁电流,计算出地磁场的水平分量和垂直分量,从而确定出地磁场的大小和方向.     

基于磁传感器MMC212的电子指南针

设计了基于各相异性磁阻传感器芯片MMC212xMG的高精度电子指南针.由于该芯片是带有片上信号处理并集成了I2C总线的完整的传感系统,允许设备直接与微处理器相连而不需要A/D转换器或定时器,所以用该电路制作的电子指南针具有外围电路简单、功耗低、体积小的特点.     

A sacred geometry of the equilateral triangle

In this article, we investigate the construction of spirals on an equilateral triangle and prove that these spirals are geometric. In further analysing these spirals we show that both the male (straight line segments) and female (curves) forms of the spiral exhibit exactly the same growth ratios and that these growth ratios are constant independent of the iteration of the spiral. In particular, we show that ratio of any two successive radius vectors from the ‘centre’ of the spiral as we move inwards towards that ‘centre’ is always 1/2. This same elegant result is also shown to be true for successive chords. All our results are demonstrated using mostly coordinate and transformational geometry. Finally we look at two methods for constructing these spirals with ruler and compass to maximum accuracy.     

ADCP与光纤陀螺罗经组合导航

为了实现声学多普勒流剖面仪(ADCP)的航海导航定位功能,提出了ADCP与光纤陀螺罗经进行组合导航的方案,研究了利用光纤陀螺罗经辅助ADCP进行导航定位的方法,分析比较了ADCP独立进行航位推算和光纤陀螺罗经辅助ADCP进行组合导航的精度。试验结果表明,光纤陀螺罗经辅助ADCP进行组合导航的定位精度至少提高1倍以上,其定位精度可以达到150m/h,能够满足航海导航定位的要求。     

Two-dimensional quantum compass model in a staggered field: some rigorous results

We study the properties of the two-dimensional quantum compass model in a staggered field. Using the Perron--Fröbenius theorem and the reflection positivity method, we rigorously determine the low energy spectrum of this model and its global ground state Ψ₀. Furthermore, we show that Ψ₀ has a directional long-range order.