天顶仪

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。

IPMS In addition to using the latitude observation stations ILS information, will be the international use of Astrolabe, compared with instruments such as the zenith tube observations get latitude information to an integrated manner, regularly publishes research and analysis in polar coordinates and polar motion.

IPMS除了利用ILS台站的纬度观测资料外，将国际上利用等高仪，相天顶筒等仪器观测得到的纬度资料来综合处理，定期发表地极坐标并研究分析极移。

According to the engineering practice, the theoretical basis and method that survey directly the horizontal distance and height difference by the total station system as fourth grade and below fourth grade control network are put forward instead of surveying slant distance and zenith distance.

摘要根据工程实践，提出了用全站仪直接测量平距、高差来代替测斜距、天顶距作四等及四等以下控制网测量的理论依据和方法，并以张河湾抽水蓄能电站施工控制网为例进行了比较计算。

Zenith telescope天顶仪It felt as if we had traveled from nadir to zenith.

感觉上我们好像已从天底走到了天顶。

Their name, geographic location are as follows: Station name of the host country Mizusawa latitude, longitude -141 ° 07'5139 ° 08'3602 Japan AAC kitab -66 ° 52'511850 Russia AC Kaluofute -8 ° 18'448941 Italy AC Gaithersburg 7 ° 1'5713202 the United States AC ukiah 128 ° 12'3512096 the United States AC stations were a uniform Zeiss Zenith device, according to a unified observed star table, observing the outline for continuous observation of latitude, from the Central Bureau of centrally ILS calculations solved polar coordinates, published and made available to the use of units of .1962 began restructuring for the international polar wander service.

它们的名称、地理位置分别为：站名经度纬度所在国水泽－141°07′5139°08′3602日本AAC基塔布－66°52′511850俄国AC卡洛福特－8°18′448941意大利AC盖瑟斯堡＋7°1′5713202美国AC尤凯亚＋128°12′3512096美国AC各台站用统一的蔡司天顶仪、按统一的观测星表、观测纲要进行连续地观测纬度，由ILS中央局统一处理计算，解出地极坐标值，发表并提供给使用单位。1962年开始改组为国际极移服务。

Zenith telescopes, spectrographic instruments and attachments, micrometers, photometers, comparators, coelostats of at least up to 65 cm diameter, and sundials of up to at least 90cm diameter rounded out the product line.

还有大到65 cm物镜直径的天顶仪、摄谱仪及配件、测微计、光度测定器、测远仪、定天镜(注：观测或拍摄天体时镜面与地轴一同转动可使图像固定不动)，大到90 cm物镜直径的日昝仪都出现在蔡司的生产线上。

Modern and practical astronomy was developed in the 18th century, and successively from the theoretical and practical solution to the Sino-satellite instrument measuring time, too Seoul Scott multi-satellite measurements such as latitude, as well as simultaneous determination of longitude and latitude Supreme Court means the emergence of theodolite, contour instrument, the satellite instrument, zenith instrument, photographic zenith tube, sextant and other useful astronomical instruments, the most commonly used is the optical theodolite .20 century, all-round practical field of astronomy 60 years after the emergence of new technologies, such as satellite Dhoop Le observation and satellite laser ranging, not only the accuracy of more than optical observations, but also greatly improved operating speed, and can provide direct point of geocentric coordinates of the ground.

现代实用天文学是18世纪发展起来的，先后从理论和实践上解决了中星仪测时、太尔各特测纬以及多星等高法同时测定经度和纬度的方法，出现了经纬仪、等高仪、中星仪、天顶仪、照相天顶筒、六分仪等实用天文学仪器，最常用的是光学全能经纬仪。20世纪60年代以后实用天文学领域出现了崭新的技术，如人造卫星多普勒观测和人卫激光测距，不但精度超过光学观测，而且作业速度大大提高，并能直接提供地面点的地心坐标。

I didn't watch TV last night, because it .

昨晚我没有看电视，因为电视机坏了。

Since this year, in a lot of villages of Beijing, TV of elevator liquid crystal was removed.

今年以来，在北京的很多小区里，电梯液晶电视被撤了下来。