GPS new L2C civil signal -- timing uses?
From http://sidt.gpsworld.com/gpssidt/article/articleDetail.jsp?id=382624 :
A successful on-orbit deployment and check-out phase enabled the
spacecraft,
launched on September 25, to begin service ahead of planned schedule.
Designed
and built by Lockheed Martin, PRN31/SVN52 transmits the new L2C civil
signal
at 1227.5 MHz.
Anyone know of the timing uses and properties of this new L2C civil signal
vis a vis the existing civil signal?
-ch
In message 004101c709bf$e7543ed0$7d01000a@fakie, "Christopher Hoover" writes:
From http://sidt.gpsworld.com/gpssidt/article/articleDetail.jsp?id=382624 :
From http://sidt.gpsworld.com/gpssidt/article/articleDetail.jsp?id=382624 :
A successful on-orbit deployment and check-out phase enabled the
spacecraft,
launched on September 25, to begin service ahead of planned schedule.
Designed
and built by Lockheed Martin, PRN31/SVN52 transmits the new L2C civil
signal
at 1227.5 MHz.
Anyone know of the timing uses and properties of this new L2C civil signal
vis a vis the existing civil signal?
Yes, it should allow us civilians to do dual-frequency reception
and thus reduce the ionospheric error somewhat.
--
Poul-Henning Kamp | UNIX since Zilog Zeus 3.20
phk@FreeBSD.ORG | TCP/IP since RFC 956
FreeBSD committer | BSD since 4.3-tahoe
Never attribute to malice what can adequately be explained by incompetence.
From: "Christopher Hoover" ch@murgatroid.com
Subject: [time-nuts] GPS new L2C civil signal -- timing uses?
Date: Thu, 16 Nov 2006 12:43:42 -0800
Message-ID: 004101c709bf$e7543ed0$7d01000a@fakie
From http://sidt.gpsworld.com/gpssidt/article/articleDetail.jsp?id=382624 :
A successful on-orbit deployment and check-out phase enabled the
spacecraft,
launched on September 25, to begin service ahead of planned schedule.
Designed
and built by Lockheed Martin, PRN31/SVN52 transmits the new L2C civil
signal
at 1227.5 MHz.
Anyone know of the timing uses and properties of this new L2C civil signal
vis a vis the existing civil signal?
Do you mean beyond that of ICD-GPS-200C?
http://www.navcen.uscg.gov/gps/geninfo/ICD-GPS-200C%20with%20IRNs%2012345.pdf
Cheers,
Magnus
Anyone know of the timing uses and properties of this
new L2C civil signal vis a vis the existing civil signal?
Do you mean beyond that of ICD-GPS-200C?
I don't know. I am unclear of the relationship between that and the "new
L2C civil signal" referred to in the article.
Are you saying both refer to the same thing? If so, what are the
implications for timing apps? (I'm happy to go back through the archives if
this has already been discussed.)
-ch
From: "Christopher Hoover" ch@murgatroid.com
Subject: RE: [time-nuts] GPS new L2C civil signal -- timing uses?
Date: Thu, 16 Nov 2006 15:40:57 -0800
Message-ID: 005f01c709d8$aa8d95a0$7d01000a@fakie
Anyone know of the timing uses and properties of this
new L2C civil signal vis a vis the existing civil signal?
Do you mean beyond that of ICD-GPS-200C?
I don't know. I am unclear of the relationship between that and the "new
L2C civil signal" referred to in the article.
Are you saying both refer to the same thing? If so, what are the
implications for timing apps? (I'm happy to go back through the archives if
this has already been discussed.)
OK. The new GPS IIR-M sats (third going up UTC 18:12 tomorrow) transmitts both
the old L1 C/A signal as well as the new L2C signals. This is totally covered
in the ICD-GPS-200D [1] (which is the one to use, not the ICD-GPS-200C, which I
incorrectly directed you to). These three signals is unencrypted and when
visible they allow for two-frequency measures on capable receivers with
suitable two-frequency antennas. Based on traditional GPS theory, this allows
the receiver to shift from a modelled delay of the ionsphere to a measure based
model ionspheric delay and the implications on time measures is much reduced
systematic error. Requirements for augmentation through reference stations is
lowered if not eliminated. Naturally, hardware cost goes up since you now have
two frequencies to deal with. If you are a teeny weeny serious you look ahead
towards the L5 and Galilleo signal structures which certainly would require
additional frequencies.
[1] http://www.navcen.uscg.gov/gps/modernization/IS-GPS-200D_w_IRN_1_7Mar06%20NS.pdf
If we get our durty hands on the propper receivers (and we will) we, as fellow
time-nuts, will have a much improved state. With Glonass in the rising on top
of this, things looks good.
Oh, and to be clear, "L2C" is actually three different signals, C/A on L2,
L2CM and L2CL. where you either have C/A on L2 or both L2CM and L2CL (at the
same time).
Cheers,
Magnus
...On a totally different (e.g. positoning) topic,
does anyone know if any major GPS equipment
manufacturer will commercialize dual frequency
(L1/L2C) GPS recivers?
...In timing, the interesting point i see is the
possibility to have a two-tier redudancy GPS
timesource (and eventually a three-tier redudancy with
the upcoming og Galileo).
For now, i will watch the sky for that guy with a big
white beard, a sleigh and eight reindeer... for that
brand new L2C time machine!!
73 de Normand Martel VE2UM
Montreal, Qc. Canada
--- Magnus Danielson cfmd@bredband.net wrote:
From: "Christopher Hoover" ch@murgatroid.com
Subject: RE: [time-nuts] GPS new L2C civil signal --
timing uses?
Date: Thu, 16 Nov 2006 15:40:57 -0800
Message-ID: 005f01c709d8$aa8d95a0$7d01000a@fakie
Anyone know of the timing uses and properties
of this
new L2C civil signal vis a vis the existing
civil signal?
Do you mean beyond that of ICD-GPS-200C?
I don't know. I am unclear of the relationship
between that and the "new
L2C civil signal" referred to in the article.
Are you saying both refer to the same thing? If
so, what are the
implications for timing apps? (I'm happy to go
back through the archives if
this has already been discussed.)
OK. The new GPS IIR-M sats (third going up UTC 18:12
tomorrow) transmitts both
the old L1 C/A signal as well as the new L2C
signals. This is totally covered
in the ICD-GPS-200D [1] (which is the one to use,
not the ICD-GPS-200C, which I
incorrectly directed you to). These three signals is
unencrypted and when
visible they allow for two-frequency measures on
capable receivers with
suitable two-frequency antennas. Based on
traditional GPS theory, this allows
the receiver to shift from a modelled delay of the
ionsphere to a measure based
model ionspheric delay and the implications on time
measures is much reduced
systematic error. Requirements for augmentation
through reference stations is
lowered if not eliminated. Naturally, hardware cost
goes up since you now have
two frequencies to deal with. If you are a teeny
weeny serious you look ahead
towards the L5 and Galilleo signal structures which
certainly would require
additional frequencies.
[1]
If we get our durty hands on the propper receivers
(and we will) we, as fellow
time-nuts, will have a much improved state. With
Glonass in the rising on top
of this, things looks good.
Oh, and to be clear, "L2C" is actually three
different signals, C/A on L2,
L2CM and L2CL. where you either have C/A on L2 or
both L2CM and L2CL (at the
same time).
Cheers,
Magnus
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Using the new L2C with suitable equipment will remove the errors due to
ionospheric delay associated with single carrier use.
There have been some articles on this recently in GPS World. Try
www.gpsworld.com if you don't subscribe.
The news release on the launch is at
http://www.gpsworld.com/gpsworld/article/articleDetail.jsp?id=382449
Also http://sidt.gpsworld.com/GPS+Modernization
Rob K
----- Original Message -----
From: "Magnus Danielson" cfmd@bredband.net
To: ch@murgatroid.com
Cc: time-nuts@febo.com
Sent: Friday, November 17, 2006 12:21 AM
Subject: Re: [time-nuts] GPS new L2C civil signal -- timing uses?
From: "Christopher Hoover" ch@murgatroid.com
Subject: RE: [time-nuts] GPS new L2C civil signal -- timing uses?
Date: Thu, 16 Nov 2006 15:40:57 -0800
Message-ID: 005f01c709d8$aa8d95a0$7d01000a@fakie
Anyone know of the timing uses and properties of this
new L2C civil signal vis a vis the existing civil signal?
Do you mean beyond that of ICD-GPS-200C?
I don't know. I am unclear of the relationship between that and the "new
L2C civil signal" referred to in the article.
Are you saying both refer to the same thing? If so, what are the
implications for timing apps? (I'm happy to go back through the archives
if
this has already been discussed.)
OK. The new GPS IIR-M sats (third going up UTC 18:12 tomorrow) transmitts
both
the old L1 C/A signal as well as the new L2C signals. This is totally
covered
in the ICD-GPS-200D [1] (which is the one to use, not the ICD-GPS-200C,
which I
incorrectly directed you to). These three signals is unencrypted and when
visible they allow for two-frequency measures on capable receivers with
suitable two-frequency antennas. Based on traditional GPS theory, this
allows
the receiver to shift from a modelled delay of the ionsphere to a measure
based
model ionspheric delay and the implications on time measures is much
reduced
systematic error. Requirements for augmentation through reference stations
is
lowered if not eliminated. Naturally, hardware cost goes up since you now
have
two frequencies to deal with. If you are a teeny weeny serious you look
ahead
towards the L5 and Galilleo signal structures which certainly would
require
additional frequencies.
[1]
http://www.navcen.uscg.gov/gps/modernization/IS-GPS-200D_w_IRN_1_7Mar06%20NS.pdf
If we get our durty hands on the propper receivers (and we will) we, as
fellow
time-nuts, will have a much improved state. With Glonass in the rising on
top
of this, things looks good.
Oh, and to be clear, "L2C" is actually three different signals, C/A on L2,
L2CM and L2CL. where you either have C/A on L2 or both L2CM and L2CL (at
the
same time).
Cheers,
Magnus
time-nuts mailing list
time-nuts@febo.com
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
From: Normand Martel martelno@yahoo.com
Subject: Re: [time-nuts] GPS new L2C civil signal -- timing uses?
Date: Thu, 16 Nov 2006 17:57:36 -0800 (PST)
Message-ID: 539667.78298.qm@web50713.mail.yahoo.com
...On a totally different (e.g. positoning) topic,
does anyone know if any major GPS equipment
manufacturer will commercialize dual frequency
(L1/L2C) GPS recivers?
...In timing, the interesting point i see is the
possibility to have a two-tier redudancy GPS
timesource (and eventually a three-tier redudancy with
the upcoming og Galileo).
A quick search showed that Trimble R7 and R8 received GPS L1 & L2C as well as
GLONASS. Leica System 1200 is a similar system. These are ment for geodesy.
Interestingly there is an L2 only receiver:
http://www.accord-products.com/gpsl2csignaltap.htm
Just searching for "GPS L2C" makes these pop up.
For now, i will watch the sky for that guy with a big
white beard, a sleigh and eight reindeer... for that
brand new L2C time machine!!
Oh, thanks for reminding me. Don't forget to check out the NORAD santa-
tracking.
http://www.noradsanta.org/index.php
Cheers,
Magnus