o, I can't hear the difference.
But, that was before GPS time. I recently found a kit for a red LED
digital clock that uses GPS and displays hours, minutes, seconds and
also tenths of seconds. Try that with a sundial! Of course, you don't
need to plug in your sundial...
Look here for the $60
Hi Brooke,
The radio controlled clock that you described that uses WWVB is very good. If
you live in Canada, America or Mexico.
But I don't think it would work in Australia or some other parts in the world.
Where the GPS signals can be received anywhere.
For the Silicon Chip GPS controlled
changed it's time rather than when it
should.) As far as I know that was never fixed.
GPS does not know about the date or daylight savings, but does have a way to get to UTC by using the accumulated offset
between GPS and UTC.
So the only way to have an accurate and self setting clock
Hi Brooke,
True, GPS doesn't know about daylight saving.
To set the clock up after building it. You use a RS232 Com terminal program, to
talk to the clock driver microprocessor. And set up the month and which Sunday
daylight saving starts and finishes.
You need to:
Set your time zone.
Daylight
Hi Roderick:
GPS knows about neither daylight savings nor the date.
The article mentions "understands the rules of daylight saving (DST)" which are a political thing so this will only work
until the rules change.
This happened to VCR players and after the rules change they are al
A recent article on the GPS analog clock driver. A better description;
http://archive.siliconchip.com.au/cms/A_92/article.html
Roderick Wall.
- Reply message -
From: "Richard Langley" <l...@unb.ca>
To: "Brooke Clarke" <bro...@pacific.net>, &quo
Thanks to all who replied to my questions about the time on GPS.
The reason I asked about the leap second. Is if the following analog clock GPS
driver included the leap second correction.
Yes it would.
http://www.altronics.com.au/p/k1129-gps-synchronised-clock-kit/
It also corrects
"This causes problems for GPS receivers that are more than a few years old
since they have no idea what year it is."
Not quite true. One of the continuously operating receivers at UNB is more than
15 years old. Please see:
http://gauss2.gge.unb.ca/gpsworld/gpsworld.nove
Hi Roderick:
GPS time is continuous, that's to say there are no leap seconds or other changes to it since it started. It uses a 10
bit binary week counter so the week number rolls over after 1024 weeks. This causes problems for GPS receivers that are
more than a few years old since they have
Here is a link to an old GPS World article on GPS and the leap second:
http://www2.unb.ca/gge/Resources/gpsworld.november99.pdf
See the "The GPS Navigation Message" sidebar in particular.
And an article from GPS World on the occasion of the previous leap second:
http://gpsworld.co
ichard
Langley
Gesendet: Montag, 30. Januar 2017 00:02
An: rodwall1...@gmail.com
Cc: sundial list <sundial@uni-koeln.de>
Betreff: Re: Time question on GPS TIME and leap second.
Yes. The navigation message transmitted by GPS satellites includes the
current leap second offset so a receiver
Yes. The navigation message transmitted by GPS satellites includes the current
leap second offset so a receiver can compute and display correct UTC.
-- Richard Langley
Sent from my iPhone
On Jan 29, 2017, at 6:05 PM,
rodwall1...@gmail.com<mailto:rodwall1...@gmail.com>
<rodwall1...@
Hi all,
Was just listening to the CrowdScience on time. Thanks to whoever posted the
link to it.
CrowdScience indicated that a leap second was not added for the GPS. They also
indicated that the GPS gives us UTC time.
Question:
The UTC time that the GPS gives. Does that have the leap second
Many thanks to all who, as typical of the list, sent relevant and interesting
posts. I would like to comment on some as follows:
IM: the confluence website - crazy but yet more fun.
RM: the old civil 'degradation' of accuracy of GPS was removed many years ago.
Dedicated GPS receivers
Hi Doug:
I recently got a used CSI LGBX Pro DGPS Receiver.
This is a CSI long wave beacon receiver with an integrated Ashtech 12 channel GPS receiver iwth an antenna that receives
both of them.
The display option with the most resolution is dddmm. and it seems to be
good to less than one
the intention of location the WGS84 meridian, some 90m east of the
Greenwich brass strip. Frank had an eTrex tracker and an app on his mobile
phone, and I had an Axxera GPS tracker linked to my iPad.
The images, if the system will let them through, show 0º 0' 0. Anyone else
willing to join this new
On 30/04/2014 19:27, J. Tallman wrote:
I wonder how well Google Earth matches up with this in terms of precision? Has
anybody ever checked?
Best,
Jim Tallman
www.spectrasundial.com
www.artisanindustrials.com
jtall...@artisanindustrials.com
513-253-5497
If you search for 51 28 39.8 N 0 00 00
, at 20:26, Thibaud Taudin Chabot tcha...@dds.nl wrote:
There is an android app called GPS averaging that can average many readings
in order to get a more realistic value of the position.
Thibaud
At 10:44 1-5-2014, Frank Evans wrote:
Greetings, fellow dialists,
Ian Maddocks asks what
On 02/05/2014 07:56, Kevin Karney
wrote:
Shame on you all - abandon this ill conceived club!! The
Sun was not involved in the conception of WGS84. You should
all be expelled from the Sundial mailing list as
On 02/05/2014 07:56, Kevin Karney
wrote:
Shame on you all - abandon this ill conceived club!! The
Sun was not involved in the conception of WGS84. You should
all be expelled from the Sundial mailing list as
.
/Bulletin of the British Sundial Society, /14, 3,//104-109, 2002with
the following: But following the Royal Society's motto /Nulius in
verba/ (don't believe a word of it) our party produced several GPS
machines and the monument' position was found to be a couple of thou.
out. The suggestion
There is an android app called GPS averaging that can average many
readings in order to get a more realistic value of the position.
Thibaud
At 10:44 1-5-2014, Frank Evans wrote:
Greetings, fellow dialists,
Ian Maddocks asks what dials are on whole number lat/long lines.
During the BSS tour
90m east of the
Greenwich brass strip. Frank had an eTrex tracker and an app on his mobile
phone, and I had an Axxera GPS tracker linked to my iPad.
The images, if the system will let them through, show 0º 0' 0. Anyone else
willing to join this new exclusive club? Plenty of places to straddle
number lat / long
lines (and why)
Good luck with the membership drive!
Ian Maddocks
Chester, UK
--- Original Message ---
From: Douglas Bateman douglas.bate...@btinternet.com
Sent: 30 April 2014 17:37
To: Sundial list sundial@uni-koeln.de
Subject: The GPS zero meridian club
This is a new
independently, Frank and I had the intention of location the WGS84 meridian, some 90m east of the Greenwich brass strip. Frank had an eTrex tracker and an app on his mobile phone, and I had an Axxera GPS tracker linked to my iPad.
The images, if the system will let them through, show 0 0' 0". A
Hi Richard:
Prior to GPS each country had their own datum, but if you want GPS to truly be Global then you need a common datum.
There were other datums prior to the World Geodetic System of 1984 (WGS84,
http://en.wikipedia.org/wiki/WGS84#Longitudes_on_WGS_84) but it's the one that's
On 30/04/2014 19:33, Brooke Clarke wrote:
Hi Richard:
Prior to GPS each country had their own datum, but if you want GPS to
truly be Global then you need a common datum. There were other datums
prior to the World Geodetic System of 1984 (WGS84,
http://en.wikipedia.org/wiki/WGS84
Meridian Club’ are chasers after ephemera. They will
need to keep coming back every few years simply to catch up...
Patrick
From: Ian Maddocks
Sent: Wednesday, April 30, 2014 6:14 PM
To: Douglas Bateman ; Sundial list
Subject: RE: The GPS zero meridian club
Hi Doug
Well there's already
On 30/04/2014 20:19, Patrick Powers
wrote:
Hi Ian,
Exactly so, and it would be
interesting to see what dials there were on such a whole
number list. But the snag in all this though is that the
Dear Doug and Roger,
You are both right to doubt claims for 0.1 arc-second precision
in azimuth using a hand-held GPS receiver but there is more to
be said before dismissing GPS outright.
Appropriately translated, 0.1 arcsec precision is equivalent
to a 2km baseline with the end points known
Good morning folk,
I have been quietly following this strand with interest.
I use GPS constantly in my research, but because of the continental-scale of
my work, I don't have to worry too much about whether or not I am getting
metre-level precision. It doesn't really matter to me
Fernando,
I am not quite sure of exactly what you were trying to determine! You need
have no worries re the accuracy of your GPS.
By old GPS, I assume that you mean an 8-satellite one (like my 8 year old
brick!). Have no worries about the accuracy of an 8-satellite GPS. I bought
my son (an avid
to rush back home clouds would immediately fly in and start
pouring
the water god wanted to send us...
After several days I picked up my old GPS and decided to use it
to
replace the stars.
I chose a far away point. A tree about 1000 m from the place I
set up the theodolite. I walked
attack US satellites - wouldn't that include
the GPS system?
I guess this would reduce us all to the most fundamental system of
navigation, Dead Reckoning.
Roger Bailey
Walking Shadow Designs
N 51 W 115
Hello All,
Claude wrote:
"The advent of satellite technology has made all this very
much ahistorical question. Is it true that US Naval midshipmen no
longerstudy use of the sextant? You can only hope that the GPS or
radio inyour lifeboat has good batteries."
I cert
Hi Allan,
Garmin makes a GPS unit called eMap. It came out in March 2000. It sells
for around $200. Service Merchandise is reducing the line of products they
sell and they have the unit for $150 around here. These units have the 2.04
version of firmware, but with a PC cable ($30 more) you
As most of you know, the US government has relaxed the restrictions on
the GPS system. Supposedly the accuracy has improved from 10 meters to 1
meter. My question is, do the actual GPS units in use permit this
accuracy? At the equator, one degree is 111,308 meters in length.
One-meter is thus
%) -- but not to 1 metre. For such accuracies you still need differential
GPS. Most receivers can be programmed to display coordinates in decimal
degrees, degrees and minutes, or degrees, minutes, and seconds. Grid
coordinates (northings and eastings are also possible). There's a wealth of
GPS
government has relinquished the controlled availabity
for the GPS system. Nevertheless, the source was not reliable
and does not hint to the original source.
Is this a confirmed news?
Best regards
- fernando
--
Fernando Cabral Padrao iX Sistemas Abertos
mailto:[EMAIL PROTECTED
the controlled availabity
for the GPS system. Nevertheless, the source was not reliable
and does not hint to the original source.
Is this a confirmed news?
Best regards
- fernando
--
Fernando Cabral Padrao iX Sistemas Abertos
mailto:[EMAIL PROTECTED] http
Hi all,
I have been skimming all the dial stuff lately and have seen a few
comments on using GPS and Compasses for orienting sundials. On my first
experimental dials I used a puck type marine hand bearing compass for
alignment. I live on a hill and was able to sight to a distant object
Bob Haselby wrote:
To reduce the error to a minimum one would use two gps units
simultaneously one at each location and with the judicious use of a cell
phone to effect simultaneity, one could minimize the total differential
error.
For good topographic conditions like yours the technique
Hello Alain MORY
As to the magnetic compass to point NS line, the most annoying problem is
that we cannot find out how much error include, even if we would correct the
deviation. We have the problem with the compass itself and the local
magnetic influence, such as iron plates and bars in the
with this house angle an with this
treee.
If the workers can follow this kind of instruction, ok. But it certainly
would be easier to put the stakes in the right place and tie a line
between them so the wall can just be built along the line.
I thought that it was possible to point with the GPS
an with this
treee.
I thought that it was possible to point with the GPS particular points
around the wanted site.
I will take relatively far points to give a better accurate guideline
(e.g. some mountains twenty km far from my wall)
Is it playable ?
Regards
Alain MORY
47°N 7°E
500 m
Alsace
an azimuth to the workers, for example by saying :
the wall must be perfectly aligned with this house angle an with this
treee.
I thought that it was possible to point with the GPS particular points
around the wanted site.
I will take relatively far points to give a better accurate guideline
Hello, sundiallers !
One crazy question isn't enough !
A second one came me in brain (or the thing I use as ;-))
How can a diallist use a GPS receiver to mesure the declination of a
wall ?
I asked me this question just some minutes before the buing of such an
apparatus ! It's very practical
At 19:36 1-3-00 +0100, you wrote:
-Original Message/Oorspronkelijk bericht--
How can a diallist use a GPS receiver to mesure the declination of a
wall ?
if it is a very long straight wall you can walk along the wall and find out
the course of this movement. Then deduct or add 90
Greetings fellow dialists,
Once again you have supplied a deluge of answers to a question of mine,
this time on GPS and its failings. What an altogether utterly amazingly
erudite group of people sundial folk must be (only joking, but thanks
muchly all the same). I now understand how the problem
My wife half-heard a piece on the radio this morning saying that GPS
instruments would fail next week unless they had previously been
modified to take account of some transmission changes. They would
simply be unable to find a position. Sound a bit like the millennium
bug. Does anyone have any
Frank,
The first GPS Week 1024 epoch rollover will occur at about midnight of 21-22
August. The rollover occurs every 1024 weeks. Date (and possibly time)
may be
incorrect for those GPS receivers that do not incorporate a workaround to
deduce the new epoch. Before reading the pages below I
My wife half-heard a piece on the radio this morning saying that GPS
instruments would fail next week unless they had previously been
modified to take account of some transmission changes. They would
simply be unable to find a position. Sound a bit like the millennium
bug. Does anyone
Frank,
Check out http://www.space.com/news/gps_rollover.html for a newspaper-style
story on the GPS rollover, due to occur 22 Aug 99.
Keith
At 13:11 8/16/99 , you wrote:
My wife half-heard a piece on the radio this morning saying that GPS
instruments would fail next week unless they had
I wrote an in depth article on the roll-over for GPS World. It's on their Web
site: http://www.gpsworld.com
-- Richard Langley
Professor of Geodesy and Precision Navigation
On Mon, 16 Aug 1999, Keith E. Brandt, M.D. wrote:
Frank,
Check out http://www.space.com/news/gps_rollover.html
Sorry to back-track to a long past thread, but read this in an RYA book on
navigation:
Accuracy and Selective Availability
The inherent accuracy of Coarse Acquisition (CA) code GPS is about 20
metres ... But it is owned and operated by the American Department of
Defence, who do not want
Roger,
Ah, the joys of a TI 59! I spent hours programming the beast to
reduce my data when I was in Antarctica in 1980. I thought it was
wonderful. Eventually I gave it away complete with all the modules,
the mag cards, the programs and the manuals to a guy who collects
them. I hope it is a
device,
that is astrolabe which was also amazing celestial computer, much more
abstract than celestial globe.
GPS does not have soul but its inventors feel warmly about it. The idea was
incredible, theoretically simple but technologically very advanced and
complex. As Mike noted satelites may
do not get the same feelings with GPS. Such instruments do not
convey the same sense of place. They are like digital watches, very useful
and accurate but flashing digits do not convey the same sense of time as a
walking shadow or moving hands.
I suspect many subscribers to this list have similar
Dear Dialers
After my recent post about GPS and sextant I got few replies to me
personally. This is really amazing how sextant catches human imagination.
No other instrument, whether telescope or theodolite, not to mention GPS,
has such fame like sextant.
Note that it is of not much use
No difference. See http://www.op.dlr.de/~igex98op/monitor/monitor.htm
-- Richard Langley
Professor of Geodesy and Precision Navigation
On Fri, 26 Mar 1999, Tom Mchugh wrote:
Dear All,
Last year there was some discussion on the List concerning
possible changes of accuracy of GPS at the time
I want to thank every body that helped me with my question about GPS accuracy.
Based on five private messages and two public messages I think I can summarize
as follows:
1) Internally GPS are very, very precise
2) The time displayed is not as precise but the error is still bellow one-second
3
. Since I am not a superman
(yet!), I would not be able to process any higher accuracy, would I? :-)
I am interested in the GPS pages, but don't worry. I am sure
I can find them using Altavista, NortherLight or any other Internet
portal.
By the way haven't you ever travelled in Brazil? Travelling
on to the second. Of course, in modern terms, only nano
seconds seems to be acceptable, but for sundial work, my Garmin would
not cause any noticeable errors.
There is a couple of web GPS pages, and I am sure that you could find
out more there. Unfortunately I can't give you the URLs at the
moment
Fernando, Your GPS is probably as good as it gets as far as time
accuracy is concerned. However your unit must be tracking or have been
locked on recently. The internal clock does not have very good long
term accuracy by itself. Actual time from the gps is accurate in the
microsecond level. We
Hello
From time to time I set my watch based on the time given by my
Garmin G38. My watch seems quite good in the sense that after
several weeks of even months it is showing about the same
time the GPS is showing.
Nevertheless, I don't know how accurate my GPS is. Is there
a standard error
GPS has been under Selective Availability since it was declared operational.
This limits horizontal positional accuracy to 100 metres at the 95% confidence
level. See http://www.cnde.iastate.edu/staff/swormley/gps/check_sa.html for
more info.
-- Richard Langley
Professor of Geodesy
and Precision Navigation
On Mon, 21 Dec 1998 [EMAIL PROTECTED] wrote:
On Mon, 21 Dec 1998, Fernando Cabral [EMAIL PROTECTED] wrote:
...This error seemed too big and too systematic to be taken
as an accident. Could it be the case that the American
government is lowering the GPS precision because
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