date:20140809


On 8/9/14, 9:36 PM, Lee Mushel wrote:

Jeeze, Brooke, I wish you hadn't brought up the possible patenting of
Time Delay Beam steering antennas!   I wonder if my highly esteemed SDR
radio which I think uses some such technology, is illegal?



long since expired..

(but, I gotta say that a lot of the patents that get published in the 
back of things like IEEE Ant and Prop Magazine seem, to me, to be pretty 
obvious..)


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Re: [time-nuts] WWVB for Time Nuts

2014-08-09 Thread Lee Mushel

Jeeze, Brooke, I wish you hadn't brought up the possible patenting of  Time 
Delay Beam steering antennas!   I wonder if my highly esteemed SDR radio 
which I think uses some such technology, is illegal?


73

Lee   K9WRU
- Original Message - 
From: "Brooke Clarke" 
To: "Discussion of precise time and frequency measurement" 


Sent: Saturday, August 09, 2014 5:20 PM
Subject: Re: [time-nuts] WWVB for Time Nuts



Hi:

When I was in high school I built an oscilloscope from a kit made by 
Electronic Instrument Co. (EICO).

AFAICR Dumont had some patent that the kit avoided.
ARAIK you can build any patented device for you own use.

The reason I like patents is that they explain many things that books 
avoid.
Time delay beam steering antennas (frequency independent unlike phased 
array antennas) (Fenwick) are patented but even today not in antenna 
books.
If you want to know what makes something a geodesic dome read the patent. 
I have a tall stack of books and none of them spell it out.


Have Fun,

Brooke Clarke
http://www.PRC68.com
http://www.end2partygovernment.com/2012Issues.html
http://www.prc68.com/I/DietNutrition.html

Jim Lux wrote:

On 8/9/14, 12:56 PM, Bob Camp wrote:

Hi

Keep in mind that the patent(s) do not keep you from building a part for 
your own use.


AS I understand it, this is not technically true. You can practice the 
patent to gain an understanding of it for the purposes of inventing 
something new that is based on that patent, or to design around it.  But 
you can't practice it, just because it's useful.


 If I patent, oh, let's say, a swing consisting of a board (of an exotic, 
but readily available, composite material) hanging from a tree limb with 
two rods (of another exotic, but readily available material), you cannot 
go out and build that swing in your backyard for your kids to play on. 
You can, however, build that swing and do testing on it, connecting load 
cells, motion tracking systems using real time kinematic GPS receivers, 
and carefully measure the variations in the period of the swing as the 
gravitational pull of the moon shifts, etc. Perhaps you are going to 
build a better swing, maybe using 3 ropes instead of 2 (since my patent 
attorney didn't write the claims well).



 Regardless of what they do / do not patent, a TimeNut can still build 
(and use for themselves) what ever they wish.




Now, if you (after careful examination) believe that the privately held 
patents keep you from building a receiver for a Federally Funded 
service - talk to your elected representatives. They are the ones who 
can / will fire up a committee to look into this sort of stuff.  I think 
I would want to have some information on license costs before I made 
that phone call though.




precisely so

Jim

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Re: [time-nuts] VLF Phase-tracking receivers.

2014-08-09 Thread Kenneth G. Gordon

On 9 Aug 2014 at 19:17, paul swed wrote:

> Ken 
> All of the phase tracking receivers no longer work due to the new bpsk wwvb
> modulation.

Hello, Paul. Yes. I knew that WWVB had switched to BPSK, but these 
receivers were specifically designed to tune to any of the VLF stations 
between 3 and 99.95 KHz. They used NAA, NPG, and GBR as examples.

> Certainly if you need accuracy any of the GPSDOs out there are
> better then the old wwvb receivers.

Well, I wasn't thinking so much of accuracy as simply watching the servos 
hunt. ;-)

> I have a 599 and will hope that the project I have been working on for far to
> long will allow it to track again.

Supposedly, it would track any of the VLF stations which transmitted 
phase-stable signals, even those which used FSK or its equivalent.

> As to the 1310s etc. Never heard of them.
> Something to search for on the internet. Regards Paul WB8TSL

Well, I have done just that.

I found two references to those: one was from a Canadian university project 
which was trying to use Phase-Tracking receivers to track the position of an 
ice-island. They were trying to use both an RMS Engineering 1312, and two 
Tracor 599s. Due to errors in their attempts to use the equipment with which 
they weren't familiar, they didn't have much luck.

The other reference was to an exchange on this very forum back in 2010...I 
think. Someone said they had been using a 1312 for 20 years.

Anyway, thanks for the help. Much appreciated.

Ken W7EKB
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Re: [time-nuts] VLF Phase-tracking receivers.

Some can. But the big mega power ones here run FSK or in reality MSK about
25-50Hz from what I can tell. The other comment I have is that there no
published data on the stability or reference. I could speculate its good
but have no idea actually.
Would have to build a receiver to figure it out.
Regards
Paul.


On Sat, Aug 9, 2014 at 7:22 PM, Brooke Clarke  wrote:

> Hi Paul:
>
> Are the phase tracking receivers able to receive any VLF stations (like
> used by the military)?
>
> Have Fun,
>
> Brooke Clarke
> http://www.PRC68.com
> http://www.end2partygovernment.com/2012Issues.html
> http://www.prc68.com/I/DietNutrition.html
>
>
> paul swed wrote:
>
>> Ken
>> All of the phase tracking receivers no longer work due to the new bpsk
>> wwvb
>> modulation.
>> Certainly if you need accuracy any of the GPSDOs out there are better then
>> the old wwvb receivers.
>>
>> I have a 599 and will hope that the project I have been working on for far
>> to long will allow it to track again.
>> As to the 1310s etc. Never heard of them. Something to search for on the
>> internet.
>> Regards
>> Paul
>> WB8TSL
>>
>>
>> On Sat, Aug 9, 2014 at 5:55 PM, Kenneth G. Gordon <
>> kgordon2...@frontier.com>
>> wrote:
>>
>>  Hello, I'm new here, but would like to get some advice, if possible.
>>>
>>> I have been going through my inventory here of items which were given to
>>> me in an estate some time ago.
>>>
>>> Amongst many other things, I find three Tracor or Textran 599 receivers.
>>> One 599-CS with its manual, a 599 (no suffix) and one labeled R-1086/URR,
>>> which is very obviously another 599. I have no manual for either of the
>>> last
>>> two.
>>>
>>> I also have an RMS Engineering of Atlanta, GA Model 1312 receiver, but
>>> the
>>> manuals (2) I have are for an RMS Engineering model 1310/1311.
>>>
>>> So my questions:
>>>
>>> 1) Are the Tracor/Textran 599s worth anything other than parts? and
>>>
>>> 2) Is there a manual available somewhere for the RMS Engineering Model
>>> 1312?
>>>
>>> 3) Is the 1312 worth anything to anyone these days?
>>>
>>>  From the manuals I have on the 599 models, I am quite impressed with
>>> their
>>> specifications.
>>>
>>> I would think about using one or the other of them except that I no
>>> longer
>>> have an extremely accurate 100 KHz signal source.
>>>
>>> Thanks,
>>>
>>> Ken Gordon W7EKB
>>> ___
>>> time-nuts mailing list -- time-nuts@febo.com
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>>>
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Re: [time-nuts] WWVB for Time Nuts


On 8/9/14, 12:27 PM, John Seamons wrote:

On Aug 10, 2014, at 5:49 AM, Brooke Clarke  wrote:

I don't understand how Xtendwave can get patents when their work was partially 
funded by NIST?


We had this discussion a few years back: 




Ah yes... SBIR..
Even trickier than Bayh-Dole..
Small business gets the rights (gov't purpose rights still part of the 
deal), and worse than B-D, they can keep all the test data and design 
data proprietary for something like 5 years.  At least with B-D, the 
info is published.


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Re: [time-nuts] VLF Phase-tracking receivers.


Hi Paul:

Are the phase tracking receivers able to receive any VLF stations (like used by 
the military)?

Have Fun,

Brooke Clarke
http://www.PRC68.com
http://www.end2partygovernment.com/2012Issues.html
http://www.prc68.com/I/DietNutrition.html

paul swed wrote:

Ken
All of the phase tracking receivers no longer work due to the new bpsk wwvb
modulation.
Certainly if you need accuracy any of the GPSDOs out there are better then
the old wwvb receivers.

I have a 599 and will hope that the project I have been working on for far
to long will allow it to track again.
As to the 1310s etc. Never heard of them. Something to search for on the
internet.
Regards
Paul
WB8TSL


On Sat, Aug 9, 2014 at 5:55 PM, Kenneth G. Gordon 
wrote:


Hello, I'm new here, but would like to get some advice, if possible.

I have been going through my inventory here of items which were given to
me in an estate some time ago.

Amongst many other things, I find three Tracor or Textran 599 receivers.
One 599-CS with its manual, a 599 (no suffix) and one labeled R-1086/URR,
which is very obviously another 599. I have no manual for either of the
last
two.

I also have an RMS Engineering of Atlanta, GA Model 1312 receiver, but the
manuals (2) I have are for an RMS Engineering model 1310/1311.

So my questions:

1) Are the Tracor/Textran 599s worth anything other than parts? and

2) Is there a manual available somewhere for the RMS Engineering Model
1312?

3) Is the 1312 worth anything to anyone these days?

 From the manuals I have on the 599 models, I am quite impressed with their
specifications.

I would think about using one or the other of them except that I no longer
have an extremely accurate 100 KHz signal source.

Thanks,

Ken Gordon W7EKB
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Re: [time-nuts] WWVB for Time Nuts

Hi:

When I was in high school I built an oscilloscope from a kit made by Electronic
Instrument Co. (EICO).
AFAICR Dumont had some patent that the kit avoided.
ARAIK you can build any patented device for you own use.

The reason I like patents is that they explain many things that books avoid.
Time delay beam steering antennas (frequency independent unlike phased array antennas) (Fenwick) are patented but even
today not in antenna books.
If you want to know what makes something a geodesic dome read the patent. I have a tall stack of books and none of them
spell it out.

Have Fun,

Brooke Clarke
http://www.PRC68.com
http://www.end2partygovernment.com/2012Issues.html
http://www.prc68.com/I/DietNutrition.html

Jim Lux wrote:

On 8/9/14, 12:56 PM, Bob Camp wrote:

Keep in mind that the patent(s) do not keep you from building a part for your
own use.

AS I understand it, this is not technically true. You can practice the patent to gain an understanding of it for the
purposes of inventing something new that is based on that patent, or to design around it. But you can't practice it,
just because it's useful.

If I patent, oh, let's say, a swing consisting of a board (of an exotic, but readily available, composite material)
hanging from a tree limb with two rods (of another exotic, but readily available material), you cannot go out and
build that swing in your backyard for your kids to play on. You can, however, build that swing and do testing on it,
connecting load cells, motion tracking systems using real time kinematic GPS receivers, and carefully measure the
variations in the period of the swing as the gravitational pull of the moon shifts, etc. Perhaps you are going to
build a better swing, maybe using 3 ropes instead of 2 (since my patent attorney didn't write the claims well).

Regardless of what they do / do not patent, a TimeNut can still build (and use
for themselves) what ever they wish.

Now, if you (after careful examination) believe that the privately held patents keep you from building a receiver for
a Federally Funded service - talk to your elected representatives. They are the ones who can / will fire up a
committee to look into this sort of stuff. I think I would want to have some information on license costs before I
made that phone call though.

precisely so

Jim

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Re: [time-nuts] VLF Phase-tracking receivers.

Ken
All of the phase tracking receivers no longer work due to the new bpsk wwvb
modulation.
Certainly if you need accuracy any of the GPSDOs out there are better then
the old wwvb receivers.

I have a 599 and will hope that the project I have been working on for far
to long will allow it to track again.
As to the 1310s etc. Never heard of them. Something to search for on the
internet.
Regards
Paul
WB8TSL


On Sat, Aug 9, 2014 at 5:55 PM, Kenneth G. Gordon 
wrote:

> Hello, I'm new here, but would like to get some advice, if possible.
>
> I have been going through my inventory here of items which were given to
> me in an estate some time ago.
>
> Amongst many other things, I find three Tracor or Textran 599 receivers.
> One 599-CS with its manual, a 599 (no suffix) and one labeled R-1086/URR,
> which is very obviously another 599. I have no manual for either of the
> last
> two.
>
> I also have an RMS Engineering of Atlanta, GA Model 1312 receiver, but the
> manuals (2) I have are for an RMS Engineering model 1310/1311.
>
> So my questions:
>
> 1) Are the Tracor/Textran 599s worth anything other than parts? and
>
> 2) Is there a manual available somewhere for the RMS Engineering Model
> 1312?
>
> 3) Is the 1312 worth anything to anyone these days?
>
> From the manuals I have on the 599 models, I am quite impressed with their
> specifications.
>
> I would think about using one or the other of them except that I no longer
> have an extremely accurate 100 KHz signal source.
>
> Thanks,
>
> Ken Gordon W7EKB
> ___
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> To unsubscribe, go to
> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
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Re: [time-nuts] WWVB for Time Nuts


On 8/9/14, 3:49 PM, Bob Camp wrote:

Hi

That’s not the way it was presented to me. My understanding is that the case 
law on proving “individual study” versus “individual use” is a bit murky.  I’m 
certainly no lawyer (thank goodness ..).




murky is a good way to describe it...

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Re: [time-nuts] WWVB for Time Nuts

2014-08-09 Thread John Seamons

On Aug 10, 2014, at 5:49 AM, Brooke Clarke  wrote:
> I don't understand how Xtendwave can get patents when their work was 
> partially funded by NIST?

We had this discussion a few years back: 

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[time-nuts] VLF Phase-tracking receivers.

2014-08-09 Thread Kenneth G. Gordon

Hello, I'm new here, but would like to get some advice, if possible.

I have been going through my inventory here of items which were given to 
me in an estate some time ago.

Amongst many other things, I find three Tracor or Textran 599 receivers. 
One 599-CS with its manual, a 599 (no suffix) and one labeled R-1086/URR, 
which is very obviously another 599. I have no manual for either of the last 
two.

I also have an RMS Engineering of Atlanta, GA Model 1312 receiver, but the 
manuals (2) I have are for an RMS Engineering model 1310/1311.

So my questions: 

1) Are the Tracor/Textran 599s worth anything other than parts? and 

2) Is there a manual available somewhere for the RMS Engineering Model 
1312?

3) Is the 1312 worth anything to anyone these days?

>From the manuals I have on the 599 models, I am quite impressed with their 
specifications.

I would think about using one or the other of them except that I no longer 
have an extremely accurate 100 KHz signal source.

Thanks, 

Ken Gordon W7EKB
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Re: [time-nuts] WWVB for Time Nuts

Hi

That’s not the way it was presented to me. My understanding is that the case 
law on proving “individual study” versus “individual use” is a bit murky.  I’m 
certainly no lawyer (thank goodness ..).

Bob

On Aug 9, 2014, at 6:38 PM, Jim Lux  wrote:

> On 8/9/14, 12:56 PM, Bob Camp wrote:
>> Hi
>> 
>> Keep in mind that the patent(s) do not keep you from building a part for 
>> your own use.
> 
> AS I understand it, this is not technically true. You can practice the patent 
> to gain an understanding of it for the purposes of inventing something new 
> that is based on that patent, or to design around it.  But you can't practice 
> it, just because it's useful.
> 
> If I patent, oh, let's say, a swing consisting of a board (of an exotic, but 
> readily available, composite material) hanging from a tree limb with two rods 
> (of another exotic, but readily available material), you cannot go out and 
> build that swing in your backyard for your kids to play on.  You can, 
> however, build that swing and do testing on it, connecting load cells, motion 
> tracking systems using real time kinematic GPS receivers, and carefully 
> measure the variations in the period of the swing as the gravitational pull 
> of the moon shifts, etc. Perhaps you are going to build a better swing, maybe 
> using 3 ropes instead of 2 (since my patent attorney didn't write the claims 
> well).
> 
> 
> Regardless of what they do / do not patent, a TimeNut can still build (and 
> use for themselves) what ever they wish.
>> 
>> 
>> 
>> Now, if you (after careful examination) believe that the privately held 
>> patents keep you from building a receiver for a Federally Funded service - 
>> talk to your elected representatives. They are the ones who can / will fire 
>> up a committee to look into this sort of stuff.  I think I would want to 
>> have some information on license costs before I made that phone call though.
>> 
> 
> precisely so
> 
> Jim
> 
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Re: [time-nuts] Low noise powersupplies

2014-08-09 Thread Mike Monett

  David,

  Did you ever get an answer?

  Original Post:

  Date: Fri, 08 Aug 2014 00:10:58 +1000
  From: David Hooke 
  To: "bruce-cpdlzquo8hwavxtiumw...@public.gmane.org"
  Subject: Re: [time-nuts] Low noise powersupplies
  Message-ID: <53e388f2@gmail.com>

  > Such as?

  > david

  > On 7/08/2014 9:30 PM,
  > bruce-cpdlzquo8hwavxtiumw...@public.gmane.org wrote:

  >> I have  a couple of these. however their  noise  spectral density
  >> tends to rise precipitously below 1Hz or so. There are regulators
  >> with significantly lower flicker noise.

  >> Bruce
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Re: [time-nuts] WWVB for Time Nuts


On 8/9/14, 12:56 PM, Bob Camp wrote:

Hi

Keep in mind that the patent(s) do not keep you from building a part for your 
own use.


AS I understand it, this is not technically true. You can practice the 
patent to gain an understanding of it for the purposes of inventing 
something new that is based on that patent, or to design around it.  But 
you can't practice it, just because it's useful.


 If I patent, oh, let's say, a swing consisting of a board (of an 
exotic, but readily available, composite material) hanging from a tree 
limb with two rods (of another exotic, but readily available material), 
you cannot go out and build that swing in your backyard for your kids to 
play on.  You can, however, build that swing and do testing on it, 
connecting load cells, motion tracking systems using real time kinematic 
GPS receivers, and carefully measure the variations in the period of the 
swing as the gravitational pull of the moon shifts, etc. Perhaps you are 
going to build a better swing, maybe using 3 ropes instead of 2 (since 
my patent attorney didn't write the claims well).



 Regardless of what they do / do not patent, a TimeNut can still build 
(and use for themselves) what ever they wish.




Now, if you (after careful examination) believe that the privately held patents 
keep you from building a receiver for a Federally Funded service - talk to your 
elected representatives. They are the ones who can / will fire up a committee 
to look into this sort of stuff.  I think I would want to have some information 
on license costs before I made that phone call though.



precisely so

Jim

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Re: [time-nuts] WWVB for Time Nuts

Hi

 Doing CPU vs ASIC switch, going from 300 uA to 3 uA can matter a lot when you 
are on a little battery

If you are going to put these in 10,000,000  watches / clocks a month, then 
saving  twenty cents on a chip is a really big deal. Moving twenty cents a chip 
from your pocket to my pocket is enough to pay for a lot of development.. Yes, 
at that rate everybody in the country has a WWVB watch in three or so years. 
Cheap watch / clock lasts for a year or two …. How many watches and clocks are 
there around here…. Even at a couple million a year, the your pocket to my 
pocket math for the low power ASIC makes a lot of sense.

Bob

On Aug 9, 2014, at 5:42 PM, Ivan.Cousins  wrote:

> Time nuts:
> Here is a prediction of how it could go on the WWVB chip situation.
> Moors law will under price the custom chip price in small (and even large) 
> volumes.
> 
> It already has.
> http://en.wikipedia.org/wiki/Moore%27s_law
> 
> A WWVB receiver can now be done on an Arduino microprocessor with a little 
> help from an antenna.
> 
> The custom chip price will loose this battle.
> 
> The custom chip takes longer to develop.
> 
> A simple download can upgrade a simple carrier tracking receiver to a full 
> demodulating receiver.
> 
> The web site that supplies that free software upgrade can be anywhere on this 
> planet.
> 
> For lawyers to do their job they need a target.
> 
> Do not give them a target to aim at.
> 
> Or give them so many targets that they still can not do their job.
> 
> The antenna-receiver-Arduino board can be made in China and purchased on ebay.
> 
> I feel sorry for the team with patent(s), they are competing against the 
> whole world, and do not know it yet.
> 
> 
> This is a prediction of how it could happen.
> 
> 
> Any takers.
> 
> 
> Ivan Cousins
> 
> 
> 
> On 8/9/2014 12:56 PM, Bob Camp wrote:
>> Hi
>> 
>> Keep in mind that the patent(s) do not keep you from building a part for 
>> your own use. Regardless of what they do / do not patent, a TimeNut can 
>> still build (and use for themselves) what ever they wish.
>> 
>> 
>> 
>> Now, if you (after careful examination) believe that the privately held 
>> patents keep you from building a receiver for a Federally Funded service - 
>> talk to your elected representatives. They are the ones who can / will fire 
>> up a committee to look into this sort of stuff.  I think I would want to 
>> have some information on license costs before I made that phone call though.
>> 
>> Bob
>> 
>> On Aug 9, 2014, at 1:49 PM, Brooke Clarke  wrote:
>> 
>>> Hi:
>>> 
>>> I've been reading papers by Yingsi Liang who works for Xtendwave and she 
>>> seems to be the key person developing the new clocks.
>>> I've starting collecting info on my web page:
>>> http://www.prc68.com/I/Loop.shtml#PhaseMod
>>> I don't understand how Xtendwave can get patents when their work was 
>>> partially funded by NIST?
>>> 
>>> There are different modes that have different frame times, the Long mode 
>>> takes 17 minutes for each of: Time, DST/LY state&  Date. That's to say it 
>>> takes 51 minutes to get all three.  Since the modulation format is in 
>>> complete words their receiver has a problem with the inaccuracy of common 
>>> watch crystals.  This says that for those who have a stable LO it's much 
>>> easier to receive the BPSK signal over the times needed (probably for all 
>>> formats).
>>> 
>>> PS a new paper "Receiver Design of Radio-Controlled Clocks Based On The New 
>>> WWVB Broadcast Format" came out a few days ago.
>>> 
>>> PPS I've been having fun with theodolites and have made a table "Accuracy 
>>> of Visual Fixes" on my Navigation page with columns headed Time, Angle&  
>>> Distance based on the Earth rotation at: 
>>> http://www.prc68.com/I/Nav.shtml#Accuracy
>>> The idea is that a theodolite with some angular accuracy needs to be used 
>>> with a clock that has a equivalent accuracy to get a position fix within 
>>> some distance.
>>> 
>>> [OT] PPPS I'm also having fun looking at the pond water in my back yard.
>>> http://www.prc68.com/I/Labophot.html#Pond_Water
>>> 
>>> -- 
>>> Have Fun,
>>> 
>>> Brooke Clarke
>>> http://www.PRC68.com
>>> http://www.end2partygovernment.com/2012Issues.html
>>> http://www.prc68.com/I/DietNutrition.html
>>> 
>>> ___
>>> 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.
>> 
> 

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Re: [time-nuts] WWVB for Time Nuts


On 8/9/14, 10:49 AM, Brooke Clarke wrote:

Hi:

I've been reading papers by Yingsi Liang who works for Xtendwave and she
seems to be the key person developing the new clocks.
I've starting collecting info on my web page:
http://www.prc68.com/I/Loop.shtml#PhaseMod
I don't understand how Xtendwave can get patents when their work was
partially funded by NIST?



Very simply.. Dr. Liang works for Southern Methodist University..
Under the Bayh-Dole Act, an educational institution retains the rights 
to federally funded research at that institution. The government gets a 
"fully paid, royalty free, non-exclusive" license to use the innovation 
for government purposes.  All others can license it from the institution.


The act was designed to encourage bioengineering/genetic 
engineering/human genome research, among other things.


Working at JPL (which is "operated for NASA by the California Institute 
of Technology") we're very aware of this.  You come up with something 
new, you file a "new technology report" (NTR) (this has been standard 
government contracting practice since the 70s, preceding Bayh-Dole); 
Someone reviews it at the institution and decides whether they want to 
patent it; it then goes to the gov't agency and they make a patent 
determination (yes, the gov't holds patents, lots of them in 
communications and nuclear fields); and finally, if both say "nope", 
then you, as the innovator can ask if you can patent it.


Most of the time, they decide not to patent it.. at least at Cal Tech, 
with stuff we do at JPL, it seems that we're not making the next 
facebook, and they don't seem particularly money hungry.  If they have 
something licenseable, they'll give you a non-commercial experimentation 
license for free. Mostly, it's so they can track it, and report to 
Congress every year (a legal requirement of Bayh Dole) on how well 
Congress invested taxpayer research funds.  NASA can go to Congress and 
say "We have 3,231,310 licensees for NASA innovations ranging from 
aerogel to zero-g zymurgy, give us more R&D money"


If you want to actually sell something or do something commercial, they 
do charge a license, but it's pretty small (low single digit 
percentages, as far as I know).  I know someone who receives 1/216th (I 
think that's the number.. it's close, anyway) of the royalties on some 
GPS patent, which works out to <$100/year, in a good year.  The usual 
split on royalties is half to CalTech, half to the inventors, and if 
you're faculty at CalTech, and you give your half back, then they give 
you twice that as increased budget.


A similar process occurs for software.. file NTR, rights determination, 
then, generally, public release.  Software is substantially more complex 
because someone has to go through all the licensing agreements of what 
you used (often a hodgepodge of GPL v2/v3, Apache, BSD, and who knows 
what all) and figure out what the licensing status is.  We're *trying* 
to do open source on everything, but we don't have a big budget for 
lawyers, so it tends to be "when someone asks for it".


There is ONE person at JPL who deals with this as part of their job, and 
he deals with the products of about 5500 people, plus anything developed 
by subcontractors.  The entire Intellectual Property group is less than 
half a dozen people.Very much a case of the law grinding slow and 
exceedingly fine.


A complication on stuff that JPL does is export controls. If it 
"touches" a spacecraft, the default is "export controlled", unless 
someone really wants it otherwise.







There are different modes that have different frame times, the Long mode
takes 17 minutes for each of: Time, DST/LY state & Date. That's to say
it takes 51 minutes to get all three.  Since the modulation format is in
complete words their receiver has a problem with the inaccuracy of
common watch crystals.  This says that for those who have a stable LO
it's much easier to receive the BPSK signal over the times needed
(probably for all formats).

PS a new paper "Receiver Design of Radio-Controlled Clocks Based On The
New WWVB Broadcast Format" came out a few days ago.

PPS I've been having fun with theodolites and have made a table
"Accuracy of Visual Fixes" on my Navigation page with columns headed
Time, Angle & Distance based on the Earth rotation at:
http://www.prc68.com/I/Nav.shtml#Accuracy
The idea is that a theodolite with some angular accuracy needs to be
used with a clock that has a equivalent accuracy to get a position fix
within some distance.

[OT] PPPS I'm also having fun looking at the pond water in my back yard.
http://www.prc68.com/I/Labophot.html#Pond_Water



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Re: [time-nuts] WWVB for Time Nuts

2014-08-09 Thread Ivan.Cousins


Time nuts:
Here is a prediction of how it could go on the WWVB chip situation.
Moors law will under price the custom chip price in small (and even 
large) volumes.


It already has.
http://en.wikipedia.org/wiki/Moore%27s_law

A WWVB receiver can now be done on an Arduino microprocessor with a 
little help from an antenna.


The custom chip price will loose this battle.

The custom chip takes longer to develop.

A simple download can upgrade a simple carrier tracking receiver to a 
full demodulating receiver.


The web site that supplies that free software upgrade can be anywhere on 
this planet.


For lawyers to do their job they need a target.

Do not give them a target to aim at.

Or give them so many targets that they still can not do their job.

The antenna-receiver-Arduino board can be made in China and purchased on 
ebay.


I feel sorry for the team with patent(s), they are competing against the 
whole world, and do not know it yet.



This is a prediction of how it could happen.


Any takers.


Ivan Cousins



On 8/9/2014 12:56 PM, Bob Camp wrote:

Hi

Keep in mind that the patent(s) do not keep you from building a part for your 
own use. Regardless of what they do / do not patent, a TimeNut can still build 
(and use for themselves) what ever they wish.



Now, if you (after careful examination) believe that the privately held patents 
keep you from building a receiver for a Federally Funded service - talk to your 
elected representatives. They are the ones who can / will fire up a committee 
to look into this sort of stuff.  I think I would want to have some information 
on license costs before I made that phone call though.

Bob

On Aug 9, 2014, at 1:49 PM, Brooke Clarke  wrote:


Hi:

I've been reading papers by Yingsi Liang who works for Xtendwave and she seems 
to be the key person developing the new clocks.
I've starting collecting info on my web page:
http://www.prc68.com/I/Loop.shtml#PhaseMod
I don't understand how Xtendwave can get patents when their work was partially 
funded by NIST?

There are different modes that have different frame times, the Long mode takes 17 
minutes for each of: Time, DST/LY state&  Date. That's to say it takes 51 
minutes to get all three.  Since the modulation format is in complete words their 
receiver has a problem with the inaccuracy of common watch crystals.  This says 
that for those who have a stable LO it's much easier to receive the BPSK signal 
over the times needed (probably for all formats).

PS a new paper "Receiver Design of Radio-Controlled Clocks Based On The New WWVB 
Broadcast Format" came out a few days ago.

PPS I've been having fun with theodolites and have made a table "Accuracy of Visual 
Fixes" on my Navigation page with columns headed Time, Angle&  Distance based on the 
Earth rotation at: http://www.prc68.com/I/Nav.shtml#Accuracy
The idea is that a theodolite with some angular accuracy needs to be used with 
a clock that has a equivalent accuracy to get a position fix within some 
distance.

[OT] PPPS I'm also having fun looking at the pond water in my back yard.
http://www.prc68.com/I/Labophot.html#Pond_Water

--
Have Fun,

Brooke Clarke
http://www.PRC68.com
http://www.end2partygovernment.com/2012Issues.html
http://www.prc68.com/I/DietNutrition.html

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Re: [time-nuts] WWVB for Time Nuts

2014-08-09 Thread Charles Steinmetz


Brooke wrote:

I don't understand how Xtendwave can get patents when their work was 
partially funded by NIST?


Just one of the features of the new world of "public-private 
partnerships," which have been spurred on by government funding 
cutbacks.  There is lots to say about the wisdom of such 
arrangements, but the subject is much more political than technical 
so further discussion is probably well beyond the scope of the 
list.  Note that we see it also in the proposal to resurrect an 
"improved" LORAN system.


Best regards,

Charles



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Re: [time-nuts] WWVB for Time Nuts

Hi Paul:

The key point in my prior message is that the bulk of the effort at Xtendwave is to find ways around the inadequate
stability of common watch crystals.
If a time nuts quality frequency source is available then the long words can be decoded with simple circuitry. Be sure
to check out the link where I've listed her papers most with links.

http://www.prc68.com/I/Loop.shtml#PhaseMod

The DCF77 receivers that were mentioned recently are only using phase for synchronization and AM for the data even
though there's also phase data.

The dynamic range of the Xtendwave receiver is over 100 dB, they get that by using a capacitive voltage divider in front
of the LNA which has a 1.5 dB NF to start and when the attenuator is adding loss they don't care about the NF.

Have Fun,

Brooke Clarke
http://www.PRC68.com
http://www.end2partygovernment.com/2012Issues.html
http://www.prc68.com/I/DietNutrition.html

paul swed wrote:

Bob
Indeed I have no plans to sell anything. If I can ever get a digital
solution working for wwvb.
What I can say is whatever I do will be shared here. For good or bad.
Regards
Paul
WB8TSL

On Sat, Aug 9, 2014 at 3:56 PM, Bob Camp wrote:

Keep in mind that the patent(s) do not keep you from building a part for
your own use. Regardless of what they do / do not patent, a TimeNut can
still build (and use for themselves) what ever they wish.

Now, if you (after careful examination) believe that the privately held
patents keep you from building a receiver for a Federally Funded service -
talk to your elected representatives. They are the ones who can / will fire
up a committee to look into this sort of stuff. I think I would want to
have some information on license costs before I made that phone call though.

Bob

On Aug 9, 2014, at 1:49 PM, Brooke Clarke wrote:

Hi:

I've been reading papers by Yingsi Liang who works for Xtendwave and she

seems to be the key person developing the new clocks.

I've starting collecting info on my web page:
http://www.prc68.com/I/Loop.shtml#PhaseMod
I don't understand how Xtendwave can get patents when their work was

partially funded by NIST?

There are different modes that have different frame times, the Long mode

takes 17 minutes for each of: Time, DST/LY state & Date. That's to say it
takes 51 minutes to get all three. Since the modulation format is in
complete words their receiver has a problem with the inaccuracy of common
watch crystals. This says that for those who have a stable LO it's much
easier to receive the BPSK signal over the times needed (probably for all
formats).

PS a new paper "Receiver Design of Radio-Controlled Clocks Based On The

New WWVB Broadcast Format" came out a few days ago.

PPS I've been having fun with theodolites and have made a table

"Accuracy of Visual Fixes" on my Navigation page with columns headed Time,
Angle & Distance based on the Earth rotation at:
http://www.prc68.com/I/Nav.shtml#Accuracy

The idea is that a theodolite with some angular accuracy needs to be

used with a clock that has a equivalent accuracy to get a position fix
within some distance.

[OT] PPPS I'm also having fun looking at the pond water in my back yard.
http://www.prc68.com/I/Labophot.html#Pond_Water

--
Have Fun,

Brooke Clarke
http://www.PRC68.com
http://www.end2partygovernment.com/2012Issues.html
http://www.prc68.com/I/DietNutrition.html

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Re: [time-nuts] WWVB for Time Nuts

Bob
Indeed I have no plans to sell anything. If I can ever get a digital
solution working for wwvb.
What I can say is whatever I do will be shared here. For good or bad.
Regards
Paul
WB8TSL



On Sat, Aug 9, 2014 at 3:56 PM, Bob Camp  wrote:

> Hi
>
> Keep in mind that the patent(s) do not keep you from building a part for
> your own use. Regardless of what they do / do not patent, a TimeNut can
> still build (and use for themselves) what ever they wish.
>
> 
>
> Now, if you (after careful examination) believe that the privately held
> patents keep you from building a receiver for a Federally Funded service -
> talk to your elected representatives. They are the ones who can / will fire
> up a committee to look into this sort of stuff.  I think I would want to
> have some information on license costs before I made that phone call though.
>
> Bob
>
> On Aug 9, 2014, at 1:49 PM, Brooke Clarke  wrote:
>
> > Hi:
> >
> > I've been reading papers by Yingsi Liang who works for Xtendwave and she
> seems to be the key person developing the new clocks.
> > I've starting collecting info on my web page:
> > http://www.prc68.com/I/Loop.shtml#PhaseMod
> > I don't understand how Xtendwave can get patents when their work was
> partially funded by NIST?
> >
> > There are different modes that have different frame times, the Long mode
> takes 17 minutes for each of: Time, DST/LY state & Date. That's to say it
> takes 51 minutes to get all three.  Since the modulation format is in
> complete words their receiver has a problem with the inaccuracy of common
> watch crystals.  This says that for those who have a stable LO it's much
> easier to receive the BPSK signal over the times needed (probably for all
> formats).
> >
> > PS a new paper "Receiver Design of Radio-Controlled Clocks Based On The
> New WWVB Broadcast Format" came out a few days ago.
> >
> > PPS I've been having fun with theodolites and have made a table
> "Accuracy of Visual Fixes" on my Navigation page with columns headed Time,
> Angle & Distance based on the Earth rotation at:
> http://www.prc68.com/I/Nav.shtml#Accuracy
> > The idea is that a theodolite with some angular accuracy needs to be
> used with a clock that has a equivalent accuracy to get a position fix
> within some distance.
> >
> > [OT] PPPS I'm also having fun looking at the pond water in my back yard.
> > http://www.prc68.com/I/Labophot.html#Pond_Water
> >
> > --
> > Have Fun,
> >
> > Brooke Clarke
> > http://www.PRC68.com
> > http://www.end2partygovernment.com/2012Issues.html
> > http://www.prc68.com/I/DietNutrition.html
> >
> > ___
> > 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.
>
> ___
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> To unsubscribe, go to
> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
>
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Re: [time-nuts] WWVB for Time Nuts

Hi

Keep in mind that the patent(s) do not keep you from building a part for your 
own use. Regardless of what they do / do not patent, a TimeNut can still build 
(and use for themselves) what ever they wish.

Now, if you (after careful examination) believe that the privately held patents 
keep you from building a receiver for a Federally Funded service - talk to your 
elected representatives. They are the ones who can / will fire up a committee 
to look into this sort of stuff.  I think I would want to have some information 
on license costs before I made that phone call though. 

Bob

On Aug 9, 2014, at 1:49 PM, Brooke Clarke  wrote:

> Hi:
> 
> I've been reading papers by Yingsi Liang who works for Xtendwave and she 
> seems to be the key person developing the new clocks.
> I've starting collecting info on my web page:
> http://www.prc68.com/I/Loop.shtml#PhaseMod
> I don't understand how Xtendwave can get patents when their work was 
> partially funded by NIST?
> 
> There are different modes that have different frame times, the Long mode 
> takes 17 minutes for each of: Time, DST/LY state & Date. That's to say it 
> takes 51 minutes to get all three.  Since the modulation format is in 
> complete words their receiver has a problem with the inaccuracy of common 
> watch crystals.  This says that for those who have a stable LO it's much 
> easier to receive the BPSK signal over the times needed (probably for all 
> formats).
> 
> PS a new paper "Receiver Design of Radio-Controlled Clocks Based On The New 
> WWVB Broadcast Format" came out a few days ago.
> 
> PPS I've been having fun with theodolites and have made a table "Accuracy of 
> Visual Fixes" on my Navigation page with columns headed Time, Angle & 
> Distance based on the Earth rotation at: 
> http://www.prc68.com/I/Nav.shtml#Accuracy
> The idea is that a theodolite with some angular accuracy needs to be used 
> with a clock that has a equivalent accuracy to get a position fix within some 
> distance.
> 
> [OT] PPPS I'm also having fun looking at the pond water in my back yard.
> http://www.prc68.com/I/Labophot.html#Pond_Water
> 
> -- 
> Have Fun,
> 
> Brooke Clarke
> http://www.PRC68.com
> http://www.end2partygovernment.com/2012Issues.html
> http://www.prc68.com/I/DietNutrition.html
> 
> ___
> 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.

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Re: [time-nuts] WWVB for Time Nuts

Speaking of LORAN C the tests have been dead for about 6 months near as I
can tell. Not sure what happened.


On Sat, Aug 9, 2014 at 3:45 PM, Charles Steinmetz 
wrote:

> Brooke wrote:
>
>  I don't understand how Xtendwave can get patents when their work was
>> partially funded by NIST?
>>
>
> Just one of the features of the new world of "public-private
> partnerships," which have been spurred on by government funding cutbacks.
>  There is lots to say about the wisdom of such arrangements, but the
> subject is much more political than technical so further discussion is
> probably well beyond the scope of the list.  Note that we see it also in
> the proposal to resurrect an "improved" LORAN system.
>
> Best regards,
>
> Charles
>
>
>
>
> ___
> 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.
>
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[time-nuts] WWVB for Time Nuts

Hi:

I've been reading papers by Yingsi Liang who works for Xtendwave and she seems to be the key person developing the new
clocks.

I've starting collecting info on my web page:
http://www.prc68.com/I/Loop.shtml#PhaseMod
I don't understand how Xtendwave can get patents when their work was partially
funded by NIST?

There are different modes that have different frame times, the Long mode takes 17 minutes for each of: Time, DST/LY
state & Date. That's to say it takes 51 minutes to get all three. Since the modulation format is in complete words
their receiver has a problem with the inaccuracy of common watch crystals. This says that for those who have a stable
LO it's much easier to receive the BPSK signal over the times needed (probably for all formats).

PS a new paper "Receiver Design of Radio-Controlled Clocks Based On The New WWVB
Broadcast Format" came out a few days ago.

PPS I've been having fun with theodolites and have made a table "Accuracy of Visual Fixes" on my Navigation page with
columns headed Time, Angle & Distance based on the Earth rotation at: http://www.prc68.com/I/Nav.shtml#Accuracy
The idea is that a theodolite with some angular accuracy needs to be used with a clock that has a equivalent accuracy to
get a position fix within some distance.

[OT] PPPS I'm also having fun looking at the pond water in my back yard.
http://www.prc68.com/I/Labophot.html#Pond_Water

--
Have Fun,

Brooke Clarke
http://www.PRC68.com
http://www.end2partygovernment.com/2012Issues.html
http://www.prc68.com/I/DietNutrition.html

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Re: [time-nuts] GPS multipath

2014-08-09 Thread Magnus Danielson


Jim,

On 08/09/2014 07:02 PM, Jim Lux wrote:

On 8/9/14, 9:33 AM, Magnus Danielson wrote:

Jim,

On 08/09/2014 05:31 PM, Jim Lux wrote:

Clarifying my previous question..
There's no doubt that multipath exists, and how to test is fairly
straightforward, whether with multiple antennas, cables, or waving
cookie sheets around..





Ultimately, the way to find out is just to get a GPS sampler, record
some raw bits, and then run the correlator and look for the second peak
from the reflection.


Quite possible, but... outside of a chip period, the Gold-code will
relatively effectively de-correlate multi-path, so it is only within the
chip period that multi-path will affect things.



If you have a correlator process that gives you all the cross
correlation bins, it's actually easier to see multipath that is greater
than one chip away (e.g. 1 microsecond .. about 300 m, for C/A code)


Indeed. An efficient way to do that is to use the FFT correlation trick. 
If you only want narrow range, then you can have an additional 
correlator bin.


Another approach is to use the full sample-rate sample-stream of I&Q 
values after carrier frequency removal, and then to autocorrelation on 
that, and then subtract the expected autocorrelation, possibly with some 
shift. That would give you a fairly high resolution picture.


Feel tempted to try something like that.

Cheers,
Magnus
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Re: [time-nuts] GPS multipath


On 8/9/14, 9:33 AM, Magnus Danielson wrote:

Jim,

On 08/09/2014 05:31 PM, Jim Lux wrote:

Clarifying my previous question..
There's no doubt that multipath exists, and how to test is fairly
straightforward, whether with multiple antennas, cables, or waving
cookie sheets around..





Ultimately, the way to find out is just to get a GPS sampler, record
some raw bits, and then run the correlator and look for the second peak
from the reflection.


Quite possible, but... outside of a chip period, the Gold-code will
relatively effectively de-correlate multi-path, so it is only within the
chip period that multi-path will affect things.



If you have a correlator process that gives you all the cross 
correlation bins, it's actually easier to see multipath that is greater 
than one chip away (e.g. 1 microsecond .. about 300 m, for C/A code)



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Re: [time-nuts] GPS multipath

2014-08-09 Thread Tom Miller

Don't forget that the polarity of the reflection will reverse. RCP > LCP. 
and a >20 dB loss will occur.


Tom



- Original Message - 
From: "Jim Lux" 
To: "Discussion of precise time and frequency measurement" 


Sent: Saturday, August 09, 2014 11:31 AM
Subject: [time-nuts] GPS multipath



Clarifying my previous question..
There's no doubt that multipath exists, and how to test is fairly 
straightforward, whether with multiple antennas, cables, or waving cookie 
sheets around..


What I was really asking is if anyone had observed this in the output of 
their GPS receiver.


That is, say you were watching the 1pps output and comparing its to your 
ensemble of active hydrogen masers.. As you place and remove the cookie 
sheet, do you see any (fraction of a nanosecond) change in 1pps? 
(unlikely, since I assume the 1pps has a fairly long time constant).


Or more interesting, if you happened to have a GPS receiver that puts out 
raw observables of carrier or code phase, would you see a bump? Or if you 
were experimenting with your KF implementation, where you were comparing 
filter output (i.e. estimate of where it "should be") and tracking loop 
output (i.e. "where it is") would you see any discontinuity.


Ultimately, the way to find out is just to get a GPS sampler, record some 
raw bits, and then run the correlator and look for the second peak from 
the reflection.


There's been a lot of discussion over the years about good and bad 
locations for the antenna, and how multipath is a big issue with getting 
very good timing performance.  I was wondering if someone had a practical 
anecdote of better or worse performance that could be attributed to 
something on the order of a square meter.  (position inaccuracies in urban 
canyons are a good example of multipath from hundreds of square meters)


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Re: [time-nuts] GPS multipath

2014-08-09 Thread Magnus Danielson


Jim,

On 08/09/2014 05:31 PM, Jim Lux wrote:

Clarifying my previous question..
There's no doubt that multipath exists, and how to test is fairly
straightforward, whether with multiple antennas, cables, or waving
cookie sheets around..

What I was really asking is if anyone had observed this in the output of
their GPS receiver.


Yes. Just look at the deviations when making position averaging.
After position lock, monitor the residue errors of the T-RAIM.


That is, say you were watching the 1pps output and comparing its to your
ensemble of active hydrogen masers.. As you place and remove the cookie
sheet, do you see any (fraction of a nanosecond) change in 1pps?
(unlikely, since I assume the 1pps has a fairly long time constant).

Or more interesting, if you happened to have a GPS receiver that puts
out raw observables of carrier or code phase, would you see a bump? Or
if you were experimenting with your KF implementation, where you were
comparing filter output (i.e. estimate of where it "should be") and
tracking loop output (i.e. "where it is") would you see any discontinuity.


Watch the T-RAIM output if you can't get the carrier or code phase. The 
carrier phase will me much less sensitive in absolute time to multipath.


I've looked at the residue errors to some degree. The worst out-lines 
will be dropped out of the average building, but yes, it will creep 
through if you look at it. Also the residues from a T-bolt will 
illustrate this.



Ultimately, the way to find out is just to get a GPS sampler, record
some raw bits, and then run the correlator and look for the second peak
from the reflection.


Quite possible, but... outside of a chip period, the Gold-code will 
relatively effectively de-correlate multi-path, so it is only within the 
chip period that multi-path will affect things.



There's been a lot of discussion over the years about good and bad
locations for the antenna, and how multipath is a big issue with getting
very good timing performance.  I was wondering if someone had a
practical anecdote of better or worse performance that could be
attributed to something on the order of a square meter.  (position
inaccuracies in urban canyons are a good example of multipath from
hundreds of square meters)


Well, in urban canyons the problem isn't as much multi-path, but lack of 
visibility of birds that gives good geometry. You will typically see 
that the position moves widely along some corridors, which is indication 
of geometry problems, but multi-path can give similar issues, but it is 
about moving the apparent phase of the chip.


So, real life positioning or timing errors is really a mixture of the 
two effects. With good logging on good receivers, you can separate the 
effects.


Cheers,
Magnus

Cheers,
Magnus
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Re: [time-nuts] multipath on GPS

2014-08-09 Thread Chris Albertson

My experience with radar tells me it depends a lot on the geometry.  For
example a perfectly flat mirror-like reflector would only give trouble for
an instant when the angle was "correct" It would give very bright
reflection but then the satellite would move and then it would give no
reflection.On the other hand a corrugated steel roof with all those
bends reflects over a very wide angle but it is not nearly so bright.

As an example from radar.  A small corner cube reflector made from straight
metal parts can be as bright as an oil tanker ship facing head on.  One is
only a couple feet wide and the other is hundreds of feet wide.
So the trouble with the rule you are looking for is that you have to
multiply the number of square meters by some factor that varies over
several orders of magnitude and then apply the inverse square law to
account for distance.   It's that darn factor that can't be estimated well.

If you are trying to site a GPS antenna.  Buy a 1" iron pipe and a 1" pipe
flange.  The flange provides a flat mounting surface for the antenna and
the wires can fit neatly inside the pipe.   I found with my timing antenna
that the bolt pattern on the bottom exactly fit a standard pipe flange.
 Perhaps not by coincidence.

On Fri, Aug 8, 2014 at 12:39 PM, Jim Lux  wrote:

> Does anyone have a feel for what the minimum size reflector at some small
> distance would be detectable on a GPS timing receiver? WOuld you be able to
> see a change of a 1 meter square reflector 10 meters away?
>
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-- 

Chris Albertson
Redondo Beach, California
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[time-nuts] GPS multipath


Clarifying my previous question..
There's no doubt that multipath exists, and how to test is fairly 
straightforward, whether with multiple antennas, cables, or waving 
cookie sheets around..


What I was really asking is if anyone had observed this in the output of 
their GPS receiver.


That is, say you were watching the 1pps output and comparing its to your 
ensemble of active hydrogen masers.. As you place and remove the cookie 
sheet, do you see any (fraction of a nanosecond) change in 1pps? 
(unlikely, since I assume the 1pps has a fairly long time constant).


Or more interesting, if you happened to have a GPS receiver that puts 
out raw observables of carrier or code phase, would you see a bump? Or 
if you were experimenting with your KF implementation, where you were 
comparing filter output (i.e. estimate of where it "should be") and 
tracking loop output (i.e. "where it is") would you see any discontinuity.


Ultimately, the way to find out is just to get a GPS sampler, record 
some raw bits, and then run the correlator and look for the second peak 
from the reflection.


There's been a lot of discussion over the years about good and bad 
locations for the antenna, and how multipath is a big issue with getting 
very good timing performance.  I was wondering if someone had a 
practical anecdote of better or worse performance that could be 
attributed to something on the order of a square meter.  (position 
inaccuracies in urban canyons are a good example of multipath from 
hundreds of square meters)


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Re: [time-nuts] multipath on GPS