WWV WWVH and WWVB MORE THAN JUST A
WWV, WWVH, and WWVB MORE THAN JUST A TIME SIGNAL Presented to the Kingston Amateur Radio Club by Chip, VA 3 KGB 7 March 2017
Introduction • Purpose of WWV, WWVB, WWVH; • Brief histories; (very brief during presentation) • Time Stations and Frequencies; • Broadcast Formats; • Information derived from broadcasts; • Geophysical Alert Charts; and • References. Majority of this presentation is from the “ 2002 Guide to NIST Time and Frequency Services” (NIST Spec. Publ. 432, 2002) Copyrights and Trade Marks belong to their respective owners.
National Institute of Standards and Technology (NIST) • “Provides standard time and frequency information through three radio broadcast stations that are routinely used by millions of customers. The stations, WWV and WWVB, located near Fort Collins, Colorado, and WWVH, located on the island of Kauai in Hawaii, are the only radio stations located in the United States whose sole purposes are to distribute standard time and frequency information. ” 2002 Guide to NIST Time and Frequency Services
History of NIST Radio Stations • WWV − Call assigned to National Bureau of Standards (NBS), October 1919 − Testing of the station began from Washington, D. C. in May 1920, with the broadcast of Friday evening music concerts that lasted from 8: 30 to 11: 00 p. m. − On December 15, 1920, a 2 k. W spark transmitter and telegraphic code, (CW), was used to broadcast 500 word reports, called the Daily Marketgram, on 750 k. Hz. These broadcasts continued until April 15, 1921.
History of NIST Radio Stations • WWV − December 1922, it was decided that the station’s purpose would be the transmission of standard frequency signals, as a reference standard for other radio broadcasters. The first tests of WWV as a standard frequency station were conducted on January 29 − 30 of 1923. − In October 1945, the station added time announcements (Eastern Standard Time) in telegraphic code, given every 5 minutes.
History of NIST Radio Stations • WWV − In October 1945, the station added time announcements (Eastern Standard Time) in telegraphic code, given every 5 minutes. − Voice announcements of time, began on January 1, 1950, given every 5 minutes. − An experimental time code containing year, month, day, and precise time-of-day began in April 1960 and was made part of the regular broadcast in January 1961 − In 1966, WWV was moved to its current location, near Fort Collins, Colorado from Maryland.
History of NIST Radio Stations • WWV − In April 1967, began broadcasting Greenwich Mean Time (GMT) instead of local time. − In January 1974, began its current format of using Coordinated Universal Time (UTC). − July 1, 1971, time announcements now every minute, instead of every 5 minutes, and the current form of the digital time code was added. − On August 13, 1991 WWV began broadcasting voice recordings that were digitized and stored in solid state memory devices. Previous voice recordings had been played back from mechanical drum recorders, which were more prone to failure
History of NIST Radio Stations • WWV NIST Special Publication 250 -67
History of NIST Radio Stations • WWVH − Began operation on November 22, 1948 at Kihei on the island of Maui, in then territory of Hawaii. − The Hawaii location was chosen to maximize the coverage area and to prevent interference to existing users of WWV services. − The program schedule of WWVH closely followed the format of WWV. However, voice announcements of time were not added to the WWVH broadcast until July 1964, some 14 years after they first appeared on WWV.
History of NIST Radio Stations • WWVH − The original voice announcements broadcast Hawaiian Standard Time, and occurred in the first half of every fifth minute during the hour. − The original WWVH station site was being constantly threatened by an eroding shoreline, and much of the station’s equipment and property had been damaged. − It was estimated that 75 ft of shoreline were lost in the period from 1949 to 1967.
History of NIST Radio Stations • WWVH − On July 1, 1971, the station began broadcasting from its current location, a 30 acre (12 hectare) site near Kekaha on the Island of Kauai, Hawaii. This site is located on a United States Naval base called the Pacific Missile Range Facility (PMRF). − Voice announcements began every minute, using a woman’s voice. Also, the station began transmitting a digital time code for the first time, and the telegraphic time code was discontinued. − The station was now offering services nearly identical to those provided by WWV.
History of NIST Radio Stations • WWVH − In August 1991, WWVH began broadcasting voice recordings that were digitized and stored in solid state memory devices. The voice of Jane Barbe was still used for the announcements, but the digital storage device made her voice sound slightly different.
History of NIST Radio Stations • WWVB − Began operation as radio station KK 2 XEI in July 1956. − The continuous wave 60 k. Hz signal was not modulated, except for a call sign ID that was sent every 20 minutes. − The success of the 60 k. Hz broadcast led to the construction of a very low frequency (VLF) radio station named WWVL − In March 1960 the call sign WWVB was obtained. − WWVB went on the air on July 5, 1963. − A time code was added to WWVB on July 1,
History of NIST Radio Stations • WWVB
Time and Frequency Stations Station Frequencies Coordinates WWV Ft. Collins, CO 2. 5, 5, 10, 15, 20 MHz 40° 40' 49. 0" N, 105° 2' 27. 0" W WWVB Ft. Collins, CO 60 k. Hz 40° 40' 28. 3" N, 105° 2' 39. 5" W WWVH Kauai, HI 2. 5, 5, 10, 15 MHz Call Sign Country CHU Ottawa, CA 21° 59' 26. 0" N, 159° 46' 0. 0" W Shared on? 75° 45′ 22″W Language 3330, Frequencies 7850, 14670 k. Hz Always 45° 17′ 47″N (MHz) BPM China 2. 5, 5, 10, 15 Yes (, 10 MHz only) Chinese BSF Taiwan 5, 15 Yes No voice HD 2 IOA Ecuador 5 No Spanish HLA Korea 5 Yes Korean LOL Argentina 5, 10, 15 No Spanish WWV United States 2. 5, 5, 10, 15, 20 Yes English
WWV Broadcast Format
WWVH Broadcast Format
Time of Day • WWV, WWVH − Audible Time of Day announced every minute for time synchronization − BCD time code on a 100 Hz subcarrier(digital decoding) • WWWB − 60 k. Hz BCD for time decoding by radio controlled clocks and wrist watches • Low-cost receivers (“atomic clocks”) with small antennas designed to work indoors • Subject to background noise, signal blockage, clock DSP, etc. • The length of the ferrite bar antenna is less than 60 mm in most WWVB clocks, and about 15 mm in most
100 Hz Time Code • WWV and WWVH broadcast an identical time code on a 100 Hz subcarrier. • The 100 Hz frequency is usable as a standard frequency. • It is audible as an intermittent low buzzing sound on most receivers and on the telephone time-ofday service. • It originates in the time code generators, and is the only portion of the broadcasts that identify the day of year, and the last two digits of the year. • The time code is in binary coded decimal (BCD) format, where four bits represent one decimal
UT 1 Time Corrections • Applications such as celestial navigation, satellite observations of the Earth, and some types of surveying require time referenced to the rotational position of the Earth. • These users rely on the UT 1 time scale. UT 1 is derived by astronomers who monitor the speed of the Earth's rotation. • UT 1 corrections are encoded into the broadcasts by using doubled ticks during the first 16 s of each minute. − Determine the amount of the correction (in units of 0. 1 s) by counting the number of doubled ticks. • The sign of the correction depends on whether the doubled ticks occur in the first 8 s of the minute or in the second 8 s. − If the doubled ticks are in the first 8 s (1 -8) the sign is positive.
100 Hz Time Code • Each WWV/VH time code frame takes one minute to send.
Official Announcements • Several minutes of every hour on WWV/WWVH are allocated for official announcements by U. S Government agencies. − The announcements are of a public service nature and are limited to 45 seconds per segment. − More than one segment may be used by a particular agency. • NIST reserves minutes 4 and 16 (WWV), 3 and 47 (WWVH) for occasional special announcements. − These segments are used to relate information of interest to users of the time and frequency broadcasts, such as user surveys or changes to the broadcast.
Mariners • Even in today’s world where GPS receivers are widely available, a few sailors still engage in celestial navigation, and many others use it as an emergency backup to GPS. • Celestial navigation requires a small amount of equipment (sextant, calculator, compass, astronomical tables, etc. ), and an accurate time source, which can be the audio time announcements from WWV or WWVH received with a low cost shortwave portable radio. • Voice announcements of marine storm warnings on both the WWV and WWVH broadcasts. − The forecasts are updated at 0500, 1100, 1700, and 2300 UTC for WWV; and at 0000, 0600, 1200, and 1800
Astronomers • Audio time signals can be heard in the dark when clock displays can not be seen, or when the light from clock displays cannot be tolerated. • Film an astronomical event with a camcorder and play WWV in the background as a “soundtrack. ” − This audio track authenticates the time of the filmed observation, and is invaluable when sightings from different locations are compared • Use WWV/WWVH signals to time astronomical observations, including lunar occultations and meteor showers.
Radio Amateurs and Short Wave Listeners (SWL) • Radio Transmitter and Receiver Calibrations − WWV is still widely used for the calibration of both commercial and amateur transmitters, and especially by radio amateurs and shortwave listeners who use the signals to calibrate their receiver dials. • Indication of HF propagation from WWV/WWVH • The geophysical alerts provide information about the current conditions for HF radio propagation. − Updated every 3 hours (typically at 0000, 0300,
Audio Frequency Calibrations Including Standard Musical Pitch • WWV/WWVH broadcast standard audio frequencies of 440, 500, and 600 Hz for use as a traceable calibration source. • The 440 Hz (broadcast once per hour) − provides an hourly marker for chart recorders and other automated devices − serves as the ultimate reference for the calibration of pianos and other musical instruments. • Since 1939, A 440 (the musical note A above middle C at 440 Hz) has been the internationally recognized standard for musical pitch. • The piano tuner listens to a standard musical pitch and compares it to the same note on the piano keyboard. • The audio from WWV/WWVH is often used as a reference for calibrating the tuning fork or an audio tone generator.
GPS Users • Users of the Global Positioning System (GPS) can hear a 45 sec long status report at 14 and 15 minutes after the hour on WWV, and at 43 and 44 minutes after the hour on WWVH. • The reports are provided by the United States Coast Guard. .
WWV and WWVH Broadcasts Message WWVH Sponsor Broadcast Voice Male Female Time of Day (Voice Before the Minute) 7 sec 15 sec Station ID 0, 30 29, 59 North Atlantic High Seas Storm Warnings 8, 9 National Weather Service Eastern North Pacific High Seas Storm Warnings 10 National Weather Service Eastern North Pacific Storm Warnings (when necessary) 11 National Weather Service West Pacific High Seas Storm Warning 48 National Weather Service East Pacific High Seas Storm Warning 49 National Weather Service South Pacific High Seas Storm Warning 50 National Weather Service North Pacific High Seas Storm Warning 51 National Weather Service Other Pacific Storm Warnings (when necessary) 52 National Weather Service GPS Satellite Status Geophysical Alert 14, 15 43, 44 18 45 U. S. Coast Guard Navigation Center NOAA Space Environment Center
WWV Time Signal Recording of broadcast from NIST radio station WWV. Recorded on 4 September 2009, on 15 MHz, from 14: 59: 52. 3 to 15: 02 UTC. 00: 00. 2: voice announcement "At the tone, 15 hours, 0 minutes, Coordinated Universal Time“ 00: 00. 5 (between "at" and "the"): Ambient noise. It's a ship's clock in the background, ringing the last of 6 times (11: 00 EDT). This was clearly audible in the original, but might have become hard to hear after editing. 00: 07. 7: 1500 Hz top-of-hour tone (0. 8 seconds) 00: 08. 5: beginning of station ID (see article) 00: 41. 7: end of station ID 01: 00. 2: voice announcement "At the tone, 15 hours, 1 minute, Coordinated Universal Time“ 01: 07. 7: 1000 Hz end-of-minute tone (0. 8 second) 01: 08. 7: begin continuous 600 Hz tone, only interrupted by the once-per-second "ticks" (If you listen carefully, the first two ticks of this minute are doubled. This means UT 1 is 0. 2 seconds ahead of UTC. They're "under" the 600 Hz tone but can still be heard. ) 01: 35. 7: Omission of tick at 29 th second past the minute. 01: 52. 7: 600 Hz tone stops. 02: 00. 2: voice announcement "At the tone, 15 hours, 2 minutes, Coordinated Universal Time. “ 02: 07. 7: 1000 Hz end-of-minute tone 02: 08. 7: end of file
Time Signal Audio • WWV, Fort Collins, Boulder, Colorado: Recording of broadcast from NIST radio station WWV. Recorded on 4 September 2009, on 15 MHz, from 14: 59: 52. 3 to 15: 02 UTC. It's a bit noisy, but quite audible. https: //commons. wikimedia. org/w/index. php? title=File%3 AWWV_ti me_signal_-_20090904. ogg • WWVH, Kekaha, Kauai, Hawaii: Recording of WWVH from 4: 58: 43 to 5: 03: 08 UTC on March 16, 2015 on 10 MHz in Phoenix, Arizona. It has a decent amount of interference thanks to the large distance between the transmitter and the receiver (about 3000 miles/4830 km) but it is still audible in all but a few places. https: //commons. wikimedia. org/w/index. php? title=File%3 AWWVH_ recording_-_20150316. ogg
Time Signal Audio • CHU, Ottawa, Ontario: − 21 November 2010: • A typical minute's broadcast, including the Bell 103 time code and ending with the English-language announcement of 01: 26 UTC on 21 November 2010: https: //en. wikipedia. org/w/index. php? title=File%3 ACHU_minute _english_announcement. ogg • A typical minute's broadcast, including the Bell 103 time code and ending with the French-language voice announcement of 01: 43 UTC on 21 November 2010: https: //en. wikipedia. org/w/index. php? title=File%3 ACHU_french_ voice_announcement. ogg
Geophysical Alerts • Provide information about the current conditions for long distance HF radio communications. − Solar flux − A and K indices − Space Weather
Geophysical Alerts – Solar Flux • Solar flux is a measurement of the intensity of solar radio emissions with a wavelength of 10. 7 cm (a frequency of about 2800 MHz). • The daily solar flux measurement is recorded at 2000 UTC by the Dominion Radio Astrophysical Observatory of the Canadian National Research Council located at Penticton, British Columbia, Canada. • The value broadcast is in solar flux units that range from a theoretical minimum of about 50 to numbers larger than 300. − During the early part of the 11 -year sunspot cycle, the flux numbers are low; but they rise and fall as the cycle proceeds. − The numbers will remain high for extended periods around
Geophysical Alerts – A and K Indices • A measurement of the behavior of the magnetic field in and around the earth. • The K index uses a scale from 0 to 9 to measure the change in the horizontal component of the geomagnetic field. − A new K index is determined and added to the broadcast every 3 hours based on magnetometer measurements made at the Table Mountain Observatory, north of Boulder, Colorado, or an alternate middle latitude observatory. • The A index is a daily value on a scale from 0 to 400 to express the range of disturbance of the geomagnetic field. − It is obtained by converting and averaging the eight, 3 -hour K index values.
Geophysical Alerts – Space Weather • Space Weather storms observed and expected are characterized using the NOAA Space Weather scales. − Geomagnetic Storms − Solar Radiation Storms − Radio Blackouts
NOAA Space Weather Scales • Space Weather storms observed and expected are characterized using the NOAA Space Weather scales. − The abbreviated table below shows the levels of activity that are included in the announcements and the associated terminology. − The descriptor used to identify observed or expected conditions is the maximum level reached or predicted. Geomagnetic Storms Solar Radiation Storms Radio Blackouts Descriptor G 5 S 5 R 5 Extreme G 4 S 4 R 4 Severe G 3 S 3 R 3 Strong G 2 S 2 R 2 Moderate G 1 S 1 R 1 Minor
Geomagnetic Storm Levels • Geomagnetic storm levels are determined by the estimated 3 -hourly Planetary K-indices derived in real time from a network of western hemisphere groundbased magnetometers. Planetary K Indices Geomagnetic Storm Level K=5 G 1 K=6 G 2 K=7 G 3 K=8 G 4 K= 9 G 5
Solar Radiation Storm Levels • Solar Radiation storms levels are determined by the proton flux measurements made by NOAA's primary Geostationary Operational Environmental Satellite (GOES). Flux level of > 10 Me. V Particles Solar Radiation Storm Level 10 S 1 102 S 2 103 S 3 104 S 4 105 S 5
Radio Blackouts • Radio Blackout levels are determined by the x-ray level measured by the primary GOES satellite. Peak X-ray Level and Flux Radio Blackout Level M 1 and (10 -5) R 1 M 5 and (5 x 10 -5) R 2 X 1 and (10 -4) R 3 X 10 and (10 -3) R 4 X 20 and (2 x 10 -3) R 5
References and Links • WWV: https: //www. nist. gov/time-and-frequency-services/nist-radiostations/wwv • WWVB: https: //www. nist. gov/time-and-frequency-services/nist-radiostations/wwvb • WWVH: https: //www. nist. gov/time-and-frequency-services/nist-radiostations/wwvh • 2002 Guide to NIST Time and Frequency Services WWV/WWVH Station Library: https: //www. nist. gov/pml/time-and-frequency-division/timeservices/wwvwwvh-station-library
References and Links • CHU (National Research Council Canada): http: //www. nrc-cnrc. gc. ca/eng/services/time/short_wave. html http: //www. nrc-cnrc. gc. ca/fra/services/heure/ondes_courtes. html • National Weather Service: www. nws. noaa. gov • U. S. Coast Guard Navigation Center: www. navcen. uscg. gov/gps/ • NOAA Space Environment Center: www. sec. noaa. gov • HF Time Signal Stations, compiled by William Hepburn, CIDX: http: //www. dxinfocentre. com/time. htm
References and Links • Receiving, identifying and decoding LF/HF radio time signals – Nick, VK 2 DX: http: //genesisradio. com. au/VK 2 DX/time_signals. html • Seeds of time from the cesium atom - A new standard in atomic clocks: https: //www. ieee. ca/millennium/atomic_clock/atomic_seeds. html • Radio clock (“Atomic clocks”): https: //en. wikipedia. org/wiki/Radio_clock • Radio Controlled Clocks, NIST, 2003 (PDF): http: //tf. nist. gov/general/pdf/1877. pdf
References and Links • Time Signal Videos on You. Tube: − WWV And WWVH Time Signals • https: //www. youtube. com/watch? v=ZIvdr 5 LLk 8 Y − WWV 10 MHZ via remote Perseus in Canada • https: //www. youtube. com/watch? v=Blkrz. I 0 o_Uc − For other videos on time signal stations enter “time signal” into You. Tube’s search window. −
References and Links • Time Signal Videos on You. Tube: − How To Zero Beat Yaesu FT-101 B • https: //www. youtube. com/watch? v=8 hz 64 t. Tw. PH 4 − How to zero-beat WWV to check or adjust a Frequency Counter's accuracy • https: //www. youtube. com/watch? v=QCJ 4 c. QGOQLI − For other videos on calibration enter “zero beat to wwv” into You. Tube’s search window
References and Links • Radio Controlled Clock Videos on You. Tube: − MFJ-148 RC radio controlled clock atomic clock • https: //www. youtube. com/watch? v=9 amrbhbo. PXo − Do you have a problem with a Radio Control Clock? • https: //www. youtube. com/watch? v=_4 pe_50157 A − For other videos on radio controlled clocks enter
WWV - The Tick • Steve, VE 3 KC, passed this audio parody on to me so I could include it as part of the online presentation. • Source: Lownoise Productions http: //www. lownoiserecords. com/wwv_the_tick. html
73 de VA 3 KGB
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