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Автор Тема: Из истории РСДБ  (Прочитано 9745 раз)
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« Ответ #15 : 18 Август 2009, 08:08:09 »

Hello everyone,

I was on vacation when all the discussion about the history of VLBI took place.  A significant Canadian accomplishment is missing from Alan's list below.  The first geodetic use of VLBI can be attributed to H.E. Jones of the Geodetic  Survey of Canada ("Geodetic Ties Between Continents by Means of Radio Telescopes", Canadian Surveyor, 23, 377-388, 1969).  Data were
taken in February 1968 using the 2143 km baseline between the 46-m antenna in Alonquin Park and a 26-m antenna at Prince Albert, Saskatchewan.  The observations were at 448 MHz and Rb oscillators and the 4-MHz Canadian analog system were used.  A correction of +30 +/- 20 m to the geodetically determined baseline was reported.  Jones recognized that the ionosphere dominated the error budget and tried to correct for it using satellite data.  In the end, he concluded that the error of the correction would probably be as large as the effect itself.  He recommended observations at higher frequencies.

I would also like to add a footnote to the discussion of dual-band observing, in particular to why dual-band data may not have been found in the data bases until significantly later than 1969, as was pointed out by Tom Herring.  To the best of my knowledge, although data in 1969 was taken in both X- and L-band, the Haystack receiver was not capable of simultaneous dual band observation and had to be manually switched between the two bands.  Proper dual band data were not taken until later than 1969.

Anyway, a couple of points to add to the discussion.

Best regards, -Bill.
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« Ответ #16 : 18 Август 2009, 08:10:07 »

To my knowledge, the following was the first publication on successful VLBI observation:

Broten N.W., Legg T.H., Locke J.L., McLeish C.W., Richards R.S., Chisholm R.M., Gush H.P., Yen J.L., Galt J.A. Long Base Line Interferometry: A New Technique. Science, 1967, v.~156, No.~3782, 1592--1593. received: 28.03.1967, published: 06.1967

It was the Algopark - DRAO baseline, as I remember.

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Zinovy
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« Ответ #17 : 18 Август 2009, 08:10:33 »

Hi Zinovy,

Yes, you are correct that the first reported successful VLBI observations were taken in 1967, but the first observations with a _geodetic_ interpretation were those taken by Harold Jones in February 1968, using the same Canadian system as 1967 but with one of the antennas in Prince Albert.

Best regards,
-Bill.
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« Ответ #18 : 18 Август 2009, 17:13:30 »

Zinovy, Bill,

I have done a little digging to uncover a bit more history -- Hans Hintegger's thesis.  Hans reports on what I believe is the first multi-band group-delay experiment for geodesy.  It was conducted between Haystack 120' and Green Bank 140' on 11-13 January 1969.  A spanned bandwidth of 110 MHz using 6 switched-frequency 360kHz bands from 1600-1710 MHz was used.  Recording was made on the Mark I recording system at 720kbps.  The data were correlated on the CDC3300 computer at Haystack using only software (we are coming full circle now!).   Agreement between the classically-surveyed baseline and the VLBI baseline were within 2 meters in x, y and z.

-Alan
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« Ответ #19 : 18 Август 2009, 20:04:14 »

Bill,

> I think, at least according to your thesis, bandwidth synthesis was attempted as early as April and October of 1968, but the
> first successful experiment was Hans's in Jan 1969.

Yes, that is right.  The 1968 experiments were the first outings for the frequency-switched equipment and, not surprisingly, some difficulties were encountered.  The October 1968 experiment actually got good fringes, but the phase stability of the switched oscillators was not sufficient to yield good results.  The January 1969 experiment was, I believe, the first successful VLBI experiment done specifically for precision geodetic measurement.

-Alan
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« Ответ #20 : 19 Сентябрь 2011, 19:55:56 »

Dear colleagues,

It is my sad duty to inform you that Andrey Finkelstein passed
away on Sunday, September 18 after a severe illness at the age
of 70. The IVS has lost a strong supporter of its cause.

Andrey became the head of the Institute of Applied Astronomy (IAA)
of the Russian Academy of Sciences in 1988. He held a Doctorate
in Physical and Mathematical Sciences and authored more than
200 scientific papers. He was the driving force behind the
establishment of the Russian QUASAR VLBI network, among many
other accomplishments.

Andrey was very active within the IVS. He was a Board member
for many years and brought the community to Saint Petersburg
when hosting the IVS General Meeting there in 2008. We will
miss him.

Please join me in sharing our condolences with Andrey's
family, friends, and colleagues.

With sadness,

Dirk Behrend
IVS Coordinating Center
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« Ответ #21 : 23 Ноябрь 2013, 19:22:31 »

Интервью с А.М. Финкельштейном, бывшим директором ИПА РАН

Человек. Земля. Вселенная. Достижения и перспективы развития современной астрономии

http://www.youtube.com/watch?v=Y5M-x5w4Yz4

Местами не совсем корректная информация, упоминаются  прошлые, текущие и перспективные радиоастрономические проекты, система ГЛОНАСС и многое другое.
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« Ответ #22 : 04 Апрель 2014, 14:06:31 »

ИЗ ИСТОРИИ РАДИОАСТРОНОМИИ в КрАО

http://crao.crimea.ua/lra/files/hist.htm
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