盲区

As one of the most often used mountings, the altazimuth mounting satellite tracker has a blind area near the zenith because of the very high azimuth angular velocity, as a result, discontinuous observing data are caused. As for those fast flying satellites, this kind of blind area is very significant because it causes difficulties in precisely determining the satellites' orbits.

作为最常用的一种机架，采用地平式机架的人卫跟踪仪在观测天顶附近区域的目标时，由于方位转速过大而不能连续观测，存在一个固有的天顶盲区，特别是对飞行速度较快的近地卫星，这个盲区的影响是相当大的。

Double channel bandpass sampling method for wide band IF signal is presented to settle the problem of blind zone,which exchanges one more sampling channel for simplification of clock circuit and band pass filter.As a practical reconnaissance receiver, real-time processing performance must be considered.Digital channelizing method lays the base of parallel processing by multi DSP chips and discarding of the redundant data resulting from double channel bandpass sampling.

针对带通采样存在着频率覆盖盲区的问题，提出了宽带中频信号双通道带通采样的方法，通过增加一个采样通道既解决了传统处理盲区方法中设计复杂采样时钟电路、高矩形系数滤波器的困难，还缓解了后续DSP处理压力。

On this base, the system are divided into five modules: Check of front view, Check of windshield wiped area, The obstructed area check of IP formed by steering wheel, Check of binocularly obstructed angle of A pillar, and Check of rear vision for interior and exterior mirror's.

该系统分为五大模块进行研究与开发：前方视野校核模块、前风窗刮扫校核模块、仪表板盲区校核模块、A 立柱盲区校核模块、后视镜视野校核模块。

The density of blind zones relate to PRF consanguineously. Lower is PRF, lower is the density of blind zones, which is to say the infection of blind zones is lower.

测绘带盲区的密度是和PRF密切相关的，PRF越低测绘带盲区密度越小，也就说其对成像区域的影响就越小。

The 100%inspection of theses area is necessary,or both the pipe ends shall be cut off.

而石油套管必须对盲区进行100%检测，否则就要切掉两端盲区。

Under large-scale environment and so on building underlying bed, underground market, underground parking garage, the mobile communication signal is weak, the handset was unable normally to use, has formed the mobile communication blind spot and the shadow region; In among floor periphery, because comes from different base depot signal overlapping, has the pingpong effect, the handset frequent cut, even falls the speech, seriously has affected the handset normal use; In building high level, as a result of the base depot antenna high limit, is unable normally to cover, also is the mobile communication blind spot.

在大型建筑物的低层、地下商场、地下停车场等环境下，移动通信信号弱，手机无法正常使用，形成了移动通信的盲区和阴影区；在中间楼层，由于来自周围不同基站信号的重叠，产生乒乓效应，手机频繁切换，甚至掉话，严重影响了手机的正常使用；在建筑物的高层，由于受基站天线的高度限制，无法正常覆盖，也是移动通信的盲区。

Pillar vision obstruction is a main factor which affects the field of vision ofautomobile vehicle driver.

立柱盲区是影响汽车驾驶员视野的主要因素，文章就A立柱盲区的计算机辅助检验做了探讨，并在计算机上得以实现，已用于汽车驾驶员视野设计中。

The conclusion is that the extent of the zenith blind zone was restricted by three parameters: maximum azimuth angular velocity of tracking mount, flight level and airspeed of the target. In astronomical coordinates (reference mark is north latitude 43. 9°), analyzed is the effect of azimuth angular velocity, acceleration and altitude angular velocity, acceleration etc. Some formulae were given to compute all correlative quantities.

在观测坐标系中推导出确定天顶盲区理论范围公式和满足过天顶跟踪条件的关系式；在天文坐标系中以长春卫星观测站（北纬43.9°）作为计算基准，分别讨论了方位、俯仰方向的角速度、角加速度等对天顶盲区的影响，在理论分析上为解决过天顶跟踪问题打下了基础。

The conclusion is that the extent of the zenith blind zone was restricted by three parameters: maximum azimuth angular velocity of tracking mount, flight level and airspeed of the target. In astronomical coordinates (reference mark is north latitude 43.9 ), analyzed is the effect of azimuth angular velocity, acceleration and altitude angular velocity, acceleration etc. Some formulae were given to compute all correlative quantities.

在观测坐标系中推导出确定天顶盲区理论范围公式和满足过天项跟踪条件的关系式；在天文坐标系中以长春卫星观测站(北纬43.9°)作为计算基准，分别讨论了方位、俯仰方向的角速度、角加速度等对天顶盲区的影响，在理论分析上为解决过天顶跟踪问题打下了基础。

On the basis of analyzing the output signal of a two wavelength beat-wave absolute distance interferometer, this paper proceeds from the realities of the aiming method of the beat-wave interferometer, conducts an analytical investigations on the dependence of the aiming accuracy of the beat-wave interferometer on laser dual-line output power equilibrium, propose two new concepts-a basic aim blind area and a blind area expansion, and establishes an analytical expression between the blind area expansion and the relative power difference of laser dual lines.

本文从拍波干涉仪对准方法的实际出发，在分析双谱线拍波干涉仪输出信号的基础上，研究了双谱线功率不一致与拍波干涉仪对准精度的关系，提出了基本对准盲区和盲区扩大量的新概念，建立了描述盲区扩大量与双谱线相对功率差之间关系的解析表达式。

It has been put forward that there exists single Ball point and double Ball points on the symmetrical connecting-rod curves of equilateral mechanisms.

从鲍尔点的形成原理出发，分析对称连杆曲线上鲍尔点的产生条件，提出等边机构的对称连杆曲线上有单鲍尔点和双鲍尔点。

The factory affiliated to the Group primarily manufactures multiple-purpose pincers, baking kits, knives, scissors, kitchenware, gardening tools and beauty care kits as well as other hardware tools, the annual production value of which reaches US$ 30 million dollars.

集团所属工厂主要生产多用钳、烤具、刀具、剪刀、厨具、花园工具、美容套等五金产品，年生产总值3000万美元，产品价廉物美、选料上乘、质量保证，深受国内外客户的青睐