[time-nuts] Bicentennial GOES satellite clock

Sun Aug 12 23:29:39 UTC 2018

How exactly does one get submillisecond time of day precision with a
sextant?
(even if sticks and pebbles are thrown into the mix)
I'd say more like ~1 sec precision on a really fine day, it the sextant is
wielded by
a skilled and practiced operator who has apriori knowledge of his location.

And what about standard frequency dissemination?

I'm also upset about the notion of time distribution and transfer by
internet.  Now
there's a fine example of a system that could be brought down by a single
competent
hacker!

And all it takes is one really good solar flare to bring down GPS (and
Glonass and
the others) semipermanently, if the reports I read are true.

I argue that instead of shutting down distribution avenues, NIST should be
making
additional ones available.

A lot has been said lately about how rapidly our technology is exploding.
But think
about how much of that is critically dependent on precision time transfer
over the
planet, and how much longer it would take mankind to recover from (insert
your favorite
disaster here) without good time and frequency transfer still up and
working.

Dana

On Sun, Aug 12, 2018 at 2:06 PM, djl <djl at montana.com> wrote:

> all you need for a once a day noon fix is a level surface, a stick, and
> some pebbles.
> Don
>
>
> On 2018-08-12 08:29, Scott McGrath wrote:
>
>> And with dependence on GPS we have created a serious vulnerability as
>> too many critical pieces of infrastructure are dependent on a SINGLE
>> precision timing and positioning system.
>>
>> I can use a sextant and have a copy of Bowditch.    But they only work
>> on clear days and nights.
>>
>> if GPS goes down for any reason.   Whats the backup solution?
>>
>>
>> On Aug 10, 2018, at 2:25 PM, Lester Veenstra <m0ycm at veenstras.com> wrote:
>>
>> Used to work with Wayne on two time transfer via satellite
>> Great guy
>>
>>
>> Lester B Veenstra  K1YCM  MØYCM  W8YCM   6Y6Y
>> lester at veenstras.com
>>
>> Physical and US Postal Addresses
>> 5 Shrine Club Drive (Physical)
>> HC84 452 Stable Ln (RFD USPS Mail)
>> Keyser WV 26726
>> GPS: 39.336826 N  78.982287 W (Google)
>> GPS: 39.33682 N  78.9823741 W (GPSDO)
>>
>>
>> Telephones:
>> Home:                     +1-304-289-6057
>> US cell                    +1-304-790-9192
>> Jamaica cell:           +1-876-456-8898
>>
>>
>> -----Original Message-----
>> From: time-nuts [mailto:time-nuts-bounces at lists.febo.com] On Behalf Of
>> Tom
>> Van Baak
>> Sent: Friday, August 10, 2018 10:19 AM
>> To: Discussion of precise time and frequency measurement
>> Subject: Re: [time-nuts] Bicentennial GOES satellite clock
>>
>> Tim,
>>
>> Thanks for posting that photo. That space age 1976 GOES clock caught our
>> eyes when the paper came out in 2005 (see also pages 11, 12, 13):
>>
>> https://tf.nist.gov/general/pdf/2013.pdf
>>
>> There was quite a bit of traffic on time-nuts around 2005 when the GOES
>> satellite time service was turned off (and back on, and off, and on, and
>> finally off for good). That left many of us with piles of 468 MHz GOES
>> receivers, antennae, clocks and led to efforts to re-create the RF signals
>> in-home so that GOES clocks would still work. There was even a commercial
>> G2G (GPS to GOES) translator.
>>
>> Anyway, I asked around about that one-off bicentennial clock in the photo
>> and neither the authors, NIST, or Smithsonian knows where it ended up.
>> There's tons of information on the GOES satellite system and GOES clocks
>> in
>> the NIST T&F archives:
>>
>> https://tf.nist.gov/general/publications.htm
>>
>> Best to search title for GOES, or search author for Hanson. It's a
>> fascinating glimpse into the recent past. Yes, it's sad that GOES (and
>> Omega, and Loran-C) aren't operational anymore, but GPS does such a better
>> job. Plus we now have cable, WiFi, cell phones, the internet, Iridium,
>> etc.
>>
>> If you wanted to build your own Bicentennial GOES Clock, the design was
>> published, including source code -- for its i4004 (!!) CPU. If you have
>> even
>> one minute to spare, see attached image and click on these two PDF's:
>>
>> "Satellite Controlled Digital Clock System (patent)"
>> https://tf.nist.gov/general/pdf/1791.pdf
>>
>> "A Satellite-Controlled Digital Clock (NBS TN-681)"
>> https://tf.nist.gov/general/pdf/452.pdf
>>
>> /tvb
>>
>>
>> ----- Original Message -----
>> From: "Tim Shoppa" <tshoppa at gmail.com>
>> To: "Discussion of precise time and frequency measurement"
>> <time-nuts at lists.febo.com>
>> Sent: Wednesday, August 08, 2018 7:29 PM
>> Subject: [time-nuts] Bicentennial GOES satellite clock
>>
>>
>> See the groovy picture at
>>> https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4847573/figure/
>>> f9-j110-2lom/
>>>
>>> If anyone knows the whereabouts or history of the bicentennial GOES time
>>> clock display, please let me know!
>>>
>>> Tim N3QE
>>>
>>
>>
>>
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>
> --
> Dr. Don Latham
> PO Box 404, Frenchtown, MT, 59834
> VOX: 406-626-4304
>
>
>
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