[IGS-DCWG-65] Re: [IGS-DCWG-64] Re: Change in compression scheme

Nacho Romero nacho at canaryadvancedsolutions.com
Thu Apr 1 00:51:21 PDT 2010


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IGS-DCWG Mail      01 Apr 07:59:07 PDT 2010      Message Number 65
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Author: Nacho Romero

Dear all,

As Mike has mentioned already the issue of WIIIDE support is 
essential, for most users the .Z is already an issue as 99% of people 
grow up knowing only .zip so switching to .bz2 files is going to seem 
"foreign" to most users (non-expert).  I am assuming that Winzip can 
handle .Z, .zip, .bz2 and .gz files transparently these days but I do 
not use Windows anymore so no idea, please someone confirm, thanks.

If there is not that much difference I would suggest .gz, which is 
already an improvement over .Z, since "gzip" is more common and well 
known. On Hatanaka compressed files the difference "should" not be 
too large with .bz2 but I have not checked this in a long time so I 
am open to be contradicted.
Also bzip does not seem to be in the baseline distributions of Linux 
Ubuntu, or OS X, or SunOS, the operating systems that I generally 
use, whereas gzip is always available by default.  This is just my 
opinion and bias showing so take it for what it is worth but I think 
.gz is better known than .bz2

On the Hatanaka side I expect continued support from GSI and as the 
source code is available I have never had any problem compiling it in 
different platforms.  Mike; this is something that we need to also 
chase from the RINEX side in the IC! we will initiate contacts with 
GSI to see what their position is on RINEX3.0, just to be sure.


regards,

Nacho

At 18:13 -0700 31/3/10, Angelyn W. Moore wrote:
>******************************************************************************
>IGS-DCWG Mail      31 Mar 18:13:29 PDT 2010      Message Number 64
>******************************************************************************
>
>Author: Angelyn Moore
>
>Regarding vendor software, it is not unheard of to make format 
>changes that introduce dependencies on the vendor's side.  See 
>below.  We sent this directly to each vendor and reaction was very 
>positive.  We did have to chase down some responses, but several of 
>them made a point to thank us for making a clear request well in 
>advance, and I don't recall any complaints.  Note the language 
>"whether modifications can be made available to affected users," not 
>just whether modifications can be made.  If someone had said "no, we 
>need another 6 months," that would have been a fair answer.
>
>~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>  Angelyn W. Moore, Ph.D.      Geodynamics and Space Geodesy Group, 335N
>  JPL/Caltech                               Angelyn.W.Moore at jpl.nasa.gov
>  4800 Oak Grove Dr. MS 238-540                   voice: +1 818 354 5434
>  Pasadena CA 91109 USA                             fax: +1 818 393 6686
>
>
>-------- Original Message --------
>Subject: Revision of IGS orbit format requires software changes
>Date: Wed, 09 Feb 2005 17:03:43 -0800
>From: Angelyn W. Moore <Angelyn.W.Moore at jpl.nasa.gov>
>Reply-To: igscb at igscb.jpl.nasa.gov
>CC: Angelyn W Moore <Angelyn.W.Moore at jpl.nasa.gov>
>
>From: IGS Analysis Coordinator Gerd Gendt, GFZ Potsdam
>       IGS Network Coordinator Angelyn Moore, JPL
>
>Re: sp3 format revised to version sp3c;
>     software that reads sp3 orbits must be modified prior to
>     discontinuation of IGS orbits in sp3 format.
>
>Action requested: Reply to IGS Central Bureau (igscb at igscb.jpl.nasa.gov)
>advising what software is affected and whether modifications can
>be made available to affected users by 18 Sep 2005.
>
>Dear colleagues,
>
>With this e-mail we would like to draw your attention to
>some improvements introduced into the SP3 format.
>
>As announced previously in two IGSMAIL messages:
>       http://igscb/mail/igsmail/2004/msg00224.html (which
>includes a Perl script to convert sp3c to sp3) and
>       http://igscb/mail/igsmail/2004/msg00232.html (which
>discusses the error codes),
>
>the IGS has started to use a revised SP3 format called SP3-c,
>which offers many new interesting features, such as provision of
>epoch-specific accuracy codes for orbits and clocks, event flags
>and more. For details see
>     http://igscb.jpl.nasa.gov/igscb/data/format/sp3.txt
>     http://igscb.jpl.nasa.gov/igscb/data/format/sp3c.txt
>
>At present we provide all products in both formats, the usual
>sp3 files (in sp3-a format) and the new SP3-c files named with the
>file extension ".sp3c". This allows all users to prepare their
>software for the final transitions, which is foreseen for
>        GPS week 1341 beginning 18 Sep 2005.
>As of this date, sp3 version 'a' files will no longer be offered
>and all IGS orbit files will be in sp3c format, in files named
>with the .sp3 extension.
>
>As you can see from the examples, it is very easy to adopt the new
>SP3-c format.  Software must accept
>   -  the letter 'c' in addition to the letter 'a' as
>      second character in the first line,
>   -  and the character G for naming the GPS satellites.
>All the new information introduced into the SP3-c format was put
>into the '%c' and '%f' lines, as well as into the characters beyond
>position 60 in the 'P' and 'V' lines. These places were unused in the
>SP3 version 'a' format.
>
>We kindly ask you to adapt your software to support, at minimum,
>reading the information which was in sp3 files from the new sp3c
>files. Further software changes to benefit from the new SP3-c features
>are recommended, but will be at your decision.
>
>We would also like to ask you to pass this information to relevant
>customers, so that they can adapt own written software too.
>
>Please reply to the IGS Central Bureau to indicate
>  - that this message has reached appropriate personnel who can
>arrange for sp3c support in relevant software
>  - which software products are affected by the discontinuation of
>IGS sp3 version 'a' orbits
>  - whether modifications can be made available to users on the
>suggested schedule.
>
>Best regards
>
>    ACC Coordinator    Network Coordinator
>      Gerd Gendt          Angelyn Moore
>
>Example 1: present SP3 Version
>#aP2004 11 29  0  0  0.00000000      96 ORBIT IGb00 HLM  IGS
>## 1299  86400.00000000   900.00000000 53338 0.0000000000000
>+   30     1  2  3  4  5  6  7  8  9 10 11 13 14 15 16 17 18
>+         19 20 21 22 23 24 25 26 27 28 29 30 31  0  0  0  0
>+          0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0
>+          0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0
>+          0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0
>++         4  4  3  3  3  3  3  3  3  3  3  4  3  3  4  3  4
>++         4  4  3  4  4  3  3  3  3  4  3  3  3  0  0  0  0
>++         0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0
>++         0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0
>++         0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0
>%c cc cc ccc ccc cccc cccc cccc cccc ccccc ccccc ccccc ccccc
>%c cc cc ccc ccc cccc cccc cccc cccc ccccc ccccc ccccc ccccc
>%f  0.0000000  0.000000000  0.00000000000  0.000000000000000
>%f  0.0000000  0.000000000  0.00000000000  0.000000000000000
>%i    0    0    0    0      0      0      0      0         0
>%i    0    0    0    0      0      0      0      0         0
>/* RAPID ORBIT COMBINATION FROM WEIGHTED AVERAGE OF:
>/* cod emr esa gfz jpl ngs sio usn
>/* REFERENCED TO IGS TIME AND TO WEIGHTED MEAN POLE:
>/* CLK ANT Z-OFFSET (M): II/IIA 1.023; IIR 0.000
>*  2004 11 29  0  0  0.00000000
>P  1  -4700.318435  16538.932514  20422.975048    375.760870
>P  2 -12812.964800 -19886.417395  11734.891828    -80.015497
>P  3   2003.787244  16536.935378 -20761.761566     64.704179
>P  4   5690.419609 -14650.171714  21377.825999    530.470791
>P  5 -13748.267382 -11823.930349  19305.073761     62.576502
>P  6 -25023.070258   5509.386033   7410.710235    465.771466
>...
>
>Example 2: New SP3c-Version
>#cP2004 11 29  0  0  0.00000000      96 ORBIT IGb00 HLM  IGS
>## 1299  86400.00000000   900.00000000 53338 0.0000000000000
>+   30   G01G02G03G04G05G06G07G08G09G10G11G13G14G15G16G17G18
>+        G19G20G21G22G23G24G25G26G27G28G29G30G31  0  0  0  0
>+          0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0
>+          0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0
>+          0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0
>++         4  4  3  3  3  3  3  3  3  3  3  4  3  3  4  3  4
>++         4  4  3  4  4  3  3  3  3  4  3  3  3  0  0  0  0
>++         0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0
>++         0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0
>++         0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0
>%c G  cc GPS ccc cccc cccc cccc cccc ccccc ccccc ccccc ccccc
>%c cc cc ccc ccc cccc cccc cccc cccc ccccc ccccc ccccc ccccc
>%f  1.2500000  1.025000000  0.00000000000  0.000000000000000
>%f  0.0000000  0.000000000  0.00000000000  0.000000000000000
>%i    0    0    0    0      0      0      0      0         0
>%i    0    0    0    0      0      0      0      0         0
>/* RAPID ORBIT COMBINATION FROM WEIGHTED AVERAGE OF:
>/* cod emr esa gfz jpl ngs sio usn
>/* REFERENCED TO IGS TIME AND TO WEIGHTED MEAN POLE:
>/* CLK ANT Z-OFFSET (M): II/IIA 1.023; IIR 0.000
>*  2004 11 29  0  0  0.00000000
>PG01  -4700.318435  16538.932514  20422.975048    375.760870 13 13 10 193
>PG02 -12812.964800 -19886.417395  11734.891828    -80.015497 10 14 14 132
>PG03   2003.787244  16536.935378 -20761.761566     64.704179 12 11 11 170
>PG04   5690.419609 -14650.171714  21377.825999    530.470791 11 10  9 166
>PG05 -13748.267382 -11823.930349  19305.073761     62.576502 12 12  7 128
>PG06 -25023.070258   5509.386033   7410.710235    465.771466 10 12 12 178
>...


best regards,

Nacho

_______________________________________________________________

Ignacio (Nacho) Romero
Aerospace Engineer, PhD
SAC s.l. at Navigation Support Office (ESA/ESOC)
nng.esoc.esa.de
www.canaryadvancedsolutions.com
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