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BPM (time Service)
BPM is the call sign of the official short-wave time signal service of the People's Republic of China, operated by the Chinese Academy of Sciences, broadcasting from CAS's National Time Service Center in Pucheng County, Shaanxi at , roughly 70 km northeast of Lintong, along with NTSC's long-wave time signal BPL on 100 kHz. BPM is broadcast at 2.5, 5.0, 10.0, and 15.0 MHz, the same frequencies as WWV and WWVH, following the schedule listed below: Transmission format BPM transmits different signals on a half-hour schedule, modulated with 1 kHz audio tones to provide second and minute ticks: BPM is idiosyncratic in that it transmits UT1 Universal Time (UT or UT1) is a time standard based on Earth's rotation. While originally it was mean solar time at 0° longitude, precise measurements of the Sun are difficult. Therefore, UT1 is computed from a measure of the Earth's angle with ... time between minutes 25 through to 29 and 55 through to 59, which creates an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Time Signal
A time signal is a visible, audible, mechanical, or electronic signal used as a reference to determine the time of day. Church bells or voices announcing hours of prayer gave way to automatically operated chimes on public clocks; however, audible signals (even signal guns) have limited range. Busy seaports used a visual signal, the dropping of a ball, to allow mariners to check the chronometers used for navigation. The advent of electrical telegraphs allowed widespread and precise distribution of time signals from central observatories. Railways were among the first customers for time signals, which allowed synchronization of their operations over wide geographic areas. Dedicated radio time signal stations transmit a signal that allows automatic synchronization of clocks, and commercial broadcasters still include time signals in their programming. Today, global navigation satellite systems (GNSS) radio signals are used to precisely distribute time signals over much of the world ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
People's Republic Of China
China, officially the People's Republic of China (PRC), is a country in East Asia. It is the world's most populous country, with a population exceeding 1.4 billion, slightly ahead of India. China spans the equivalent of five time zones and borders fourteen countries by land, the most of any country in the world, tied with Russia. Covering an area of approximately , it is the world's third largest country by total land area. The country consists of 22 provinces, five autonomous regions, four municipalities, and two Special Administrative Regions (Hong Kong and Macau). The national capital is Beijing, and the most populous city and financial center is Shanghai. Modern Chinese trace their origins to a cradle of civilization in the fertile basin of the Yellow River in the North China Plain. The semi-legendary Xia dynasty in the 21st century BCE and the well-attested Shang and Zhou dynasties developed a bureaucratic political system to serve hereditary monarchies, or dyna ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chinese Academy Of Sciences
The Chinese Academy of Sciences (CAS); ), known by Academia Sinica in English until the 1980s, is the national academy of the People's Republic of China for natural sciences. It has historical origins in the Academia Sinica during the Republican era and was formerly also known by that name. Collectively known as the "Two Academies (两院)" along with the Chinese Academy of Engineering, it functions as the national scientific think tank and academic governing body, providing advisory and appraisal services on issues stemming from the national economy, social development, and science and technology progress. It is headquartered in Xicheng District, Beijing, with branch institutes all over mainland China. It has also created hundreds of commercial enterprises, Lenovo being one of the most famous. CAS is the world's largest research organization. It had 60,000 researchers in 2018 and 114 institutes in 2016, and has been consistently ranked among the top research organizations ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
National Time Service Center
The National Time Service Center (NTSC; ) has the task of generating, maintaining and broadcasting standard time in China. It is located in Xi'an, Shaanxi, China. Its predecessor was the Shaanxi Astronomy Observatory of the Chinese Academy of Sciences, which was established in 1966. In March 2001, the Observatory was renamed to National Time Service Center of the Chinese Academy of Sciences. NTSC includes short-wave ( BPM) and long-wave ( BPL) standard time and frequency radio stations. And in 2007, low-frequency (BPC) time signal station began trial broadcasting from Shangqiu Shangqiu (), alternately romanized as Shangkiu, is a city in eastern Henan province, Central China. It borders Kaifeng to the northwest, Zhoukou to the southwest, and the provinces of Shandong and Anhui to the northeast and southeast respectively .... References Research institutes of the Chinese Academy of Sciences 1966 establishments in China Education in Xi'an Time in China {{Sci-org-stub Ti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pucheng County, Shaanxi
Pucheng County () is a county in the east of Shaanxi province, China. It is under the administration of the prefecture-level city of Weinan Weinan () is a prefecture-level city in the east central Shaanxi province, China. The city lies on the lower section of the Wei River confluence into the Yellow River, about east of the provincial capital Xi'an, and borders the provinces of S .... Administrative divisions As 2019, Pucheng County is divided to 2 subdistricts and 15 townships. ;Subdistricts * Fengxian Subdistrict () * Zijing Subdistrict () ;Towns Climate Transport *Pucheng East Railway Station lies on the Xi'an–Yan'an Railway. References County-level divisions of Shaanxi Weinan {{Shaanxi-geo-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lintong District
Lintong District (), formerly Lintong County, is one of 11 urban districts of the prefecture-level city of Xi'an, the capital of Shaanxi Province, Northwest China. The district was approved to establish from the former ''Lintong County'' () by the Chinese State Council on June 25, 1997. The Terracotta Army and the Mausoleum of the First Qin Emperor was discovered in March 1974 near this district. The district borders the prefecture-level cities of Xianyang to the northwest and Weinan to the east, Gaoling County to the northeast, Baqiao District to the southeast, Lianhu and Xincheng Districts to the south, and Chang'an District to the southwest. Artifacts from the tomb of Qin Shi Huang, China's first emperor, can be viewed at the Emperor Qinshihuang's Mausoleum Site Museum () in Lintong District. The National Time Service Center, the Chinese Academy of Sciences (), formerly known as Shaanxi Astronomical Observatory (), was established in 1966 in Lintong responsible for the time ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
BPL (time Service)
BPL is the call sign of the official long-wave time signal service of the People's Republic of China, operated by the Chinese Academy of Sciences, broadcasting on 100 kHz from CAS's National Time Service Center in Pucheng County, Shaanxi at , roughly 70 km northeast of Lintong, along with NTSC's short-wave time signal BPM on 2.5, 5.0, 10.0, and 15.0 MHz. BPL broadcasts LORAN-C Loran-C is a hyperbolic radio navigation system that allows a receiver to determine its position by listening to low frequency radio signals that are transmitted by fixed land-based radio beacons. Loran-C combined two different techniques to ... compatible format signal from 5:30 to 13:30 UTC, using an 800 kW transmitter covering a radius up to 3000 km. References External links 长波授时 (Longwave time signal) from the National Time Service Center, Chinese Academy of Sciences {{China-stub Time signal radio stations ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Megahertz
The hertz (symbol: Hz) is the unit of frequency in the International System of Units (SI), equivalent to one event (or Cycle per second, cycle) per second. The hertz is an SI derived unit whose expression in terms of SI base units is s−1, meaning that one hertz is the reciprocal of one second. It is named after Heinrich Hertz, Heinrich Rudolf Hertz (1857–1894), the first person to provide conclusive proof of the existence of electromagnetic waves. Hertz are commonly expressed in metric prefix, multiples: kilohertz (kHz), megahertz (MHz), gigahertz (GHz), terahertz (THz). Some of the unit's most common uses are in the description of periodic waveforms and musical tones, particularly those used in radio- and audio-related applications. It is also used to describe the clock speeds at which computers and other electronics are driven. The units are sometimes also used as a representation of the photon energy, energy of a photon, via the Planck relation ''E'' = ''hν'', ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
WWV (radio Station)
WWV is a shortwave ("high frequency" or HF) radio station, located near Fort Collins, Colorado. It has broadcast a continuous time signal since 1945, and implements United States government frequency standards, with transmitters operating on 2.5, 5, 10, 15, and 20 MHz. WWV is operated by the U.S. National Institute of Standards and Technology (NIST), under the oversight of its Time and Frequency Division, which is part of NIST's Physical Measurement Laboratory based in Gaithersburg, Maryland. WWV was established in 1919 by the Bureau of Standards in Washington, D.C., making it one of the oldest continuously-operating radio stations in the United States. NIST celebrated WWV's centennial on October 1, 2019. In 1931, the station relocated to the first of three suburban Maryland sites, before moving to a location near Fort Collins in 1966. WWV shares this site with longwave (also known as "low frequency" or LF) station WWVB, which transmits carrier and time code (no voice) at 60 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
WWVH
WWVH is the callsign of the U.S. National Institute of Standards and Technology's shortwave radio time signal station located at the Barking Sands Missile Range, in Kekaha, on the island of Kauai in the state of Hawaii. WWVH is the Pacific sister station to WWV, and has a similar broadcast format. Like WWV, WWVH's main function is the dissemination of official U.S. Government time, through exactly the same methods as found on WWV's signal. To minimize interference with the WWV broadcasts on the same frequencies, WWVH's broadcasts on 5, 10 and 15 MHz are directional, pointed primarily west. Despite this strategy, in certain places, particularly on the west coast of North America; and at certain times, due to ionospheric conditions, the listener can actually hear both WWV and WWVH on the same frequency at the same time. The information modulated on the carrier is modified to reduce confusion if both are received simultaneously. In particular, voice announcements on on ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
China Standard Time
The time in China follows a single standard time offset of UTC+08:00 (eight hours ahead of Coordinated Universal Time), even though the country spans almost five geographical time zones. The official national standard time is called ''Beijing Time'' (BJT, ) domestically and ''China Standard Time'' (CST) internationally. Daylight saving time has not been observed since 1991. China Standard Time (UTC+8) is consistent across Mainland China, Hong Kong, Macau, Taiwan, Philippines, Singapore, Brunei, Mongolia, etc. History In the 1870s, the Shanghai Xujiahui Observatory was constructed by a French Catholic missionary. In 1880s officials in Shanghai French Concession started to provide a time announcement service using the Shanghai Mean Solar Time provided by the aforementioned observatory for ships into and out of Shanghai. By the end of 19th century, the time standard provided by the observatory had been switched to GMT+08:00. The practice has spread to other coastal ports, and in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Binary-coded Decimal
In computing and electronic systems, binary-coded decimal (BCD) is a class of binary encodings of decimal numbers where each digit is represented by a fixed number of bits, usually four or eight. Sometimes, special bit patterns are used for a sign or other indications (e.g. error or overflow). In byte-oriented systems (i.e. most modern computers), the term ''unpacked'' BCD usually implies a full byte for each digit (often including a sign), whereas ''packed'' BCD typically encodes two digits within a single byte by taking advantage of the fact that four bits are enough to represent the range 0 to 9. The precise 4-bit encoding, however, may vary for technical reasons (e.g. Excess-3). The ten states representing a BCD digit are sometimes called '' tetrades'' (for the nibble typically needed to hold them is also known as a tetrade) while the unused, don't care-states are named , ''pseudo-decimals'' or ''pseudo-decimal digits''. BCD's main virtue, in comparison to binary posit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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