Re: [time-nuts] BYMLBI (Back Yard Medium LBI)
Episode 211 was a good primer on celestial navigation. It covers time piece construction.
Building your own backyard continental drift hardware would be high on the coolness scale.
------Original Message------
From: Wolfgang
Sender: time-nuts-bounces@febo.com
To: Discussion of precise time and frequency measurement
ReplyTo: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] BYMLBI (Back Yard Medium LBI)
Sent: Mar 18, 2011 8:58 PM
On Friday 18 March 2011, Brooke Clarke wrote:
For a number of decades I've tried to figure out a way to measure the
period of the Earth's rotation accurate to at least 1 ms.
[...]
Is it possible to do it using a radio method in my (large) back yard?
1 ms / day = 1.2e-8 = 460um position accuracy on the ground.
If the measurement takes more than a couple of days, continental drift
may need to be considered.
- Wolfgang, DL1SKY
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
On 3/18/11 9:20 PM, lists@lazygranch.com wrote:
Episode 211 was a good primer on celestial navigation. It covers time piece construction.
Building your own backyard continental drift hardware would be high on the coolness scale.
good gps measurements processed through GIPSY at JPL would probably do
that quite nicely. Where I live, about 2 cm/year motion generally
northwards on pacific plate. And about 1 cm/year vertical motion
Building your own backyard continental drift hardware would be high on the
coolness scale.
That should be within reason for a semi-nut. All it takes is a good GPS
setup. The ballpark motion of the San Andreas fault is an inch per year.
Around here (Silicon Valley), it's reasonably common to see USGS monitoring
stations along the side of the road. There is a big sturdy tripod with a
foot diameter antanna and a dome on top with a fence around it. There is one
on the right as you are going south on101 a bit south of San Jose.
--
These are my opinions, not necessarily my employer's. I hate spam.
How about Planetized Back Yard (*) Medium LBI? If you, the measurement
enthusiast, have decent gps hardware + see yourself as 1 point in the LBI + have
good timestamps for your measurement + a decent protocol to combine them I would
say "Radio astronomy for fun & profit!". Mostly fun in this case! Combine your
local datapoints + gps derived datestamps (and estimate of uncertainty) with
those of fellow enthusiasts around the planet. Certainly looks like fun, and it
might even be useful. ;)
(*) Scale in a "back yard" concepts is a relative thing after all...
----- Original Message ----
From: Hal Murray hmurray@megapathdsl.net
To: lists@lazygranch.com; Discussion of precise time and frequency measurement
time-nuts@febo.com
Sent: Sat, March 19, 2011 8:34:41 AM
Subject: Re: [time-nuts] BYMLBI (Back Yard Medium LBI)
Building your own backyard continental drift hardware would be high on the
coolness scale.
That should be within reason for a semi-nut. All it takes is a good GPS
setup. The ballpark motion of the San Andreas fault is an inch per year.
Around here (Silicon Valley), it's reasonably common to see USGS monitoring
stations along the side of the road. There is a big sturdy tripod with a
foot diameter antanna and a dome on top with a fence around it. There is one
on the right as you are going south on101 a bit south of San Jose.
--
These are my opinions, not necessarily my employer's. I hate spam.
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
Sent from my Banana jr (tm) Mobile Device
On Mar 18, 2011, at 9:20 PM, lists@lazygranch.com wrote:
Episode 211 was a good primer on celestial navigation. It covers time piece construction.
Building your own backyard continental drift hardware would be high on the coolness scale.
------Original Message------
From: Wolfgang
Sender: time-nuts-bounces@febo.com
To: Discussion of precise time and frequency measurement
ReplyTo: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] BYMLBI (Back Yard Medium LBI)
Sent: Mar 18, 2011 8:58 PM
On Friday 18 March 2011, Brooke Clarke wrote:
For a number of decades I've tried to figure out a way to measure the
period of the Earth's rotation accurate to at least 1 ms.
[...]
Is it possible to do it using a radio method in my (large) back yard?
1 ms / day = 1.2e-8 = 460um position accuracy on the ground.
If the measurement takes more than a couple of days, continental drift
may need to be considered.
- Wolfgang, DL1SKY
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.