[IGSMAIL-4969]: Further update of RINEX compression programs

[Yuki Hatanaka <hata @ gsi.go.jp>]

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IGS Electronic Mail      12 Jul 19:17:54 PDT 2004      Message Number 4969
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Author: Yuki Hatanaka

Dear colleagues,

After the announcement of the release of the version 
2.4.1 of RNXCMP software [IGSmail #4967-8], it turned 
out that there still is a small bug in the compression 
program (RNX2CRX, not CRX2RNX).
This bug is not fatal and there is no problem to
retrieve the original RINEX file. However, it slightly 
lower compression rate by increasing chance to 
initialize differential operations, so I decided 
to fix it and to update the program again. 
I'm sorry for the frequent update.

The newest version (2.4.1a) is now avairable from 

ftp://terras.gsi.go.jp/software/RNXCMP_2.4.1a/

Note:
The decompression program (CRX2RNX) is not updated
(still 2.4.1).


Best Regards,

Yuki
-------------------------------------------------
HATANAKA,Yuki,  Geographical Survey Institute
               e-mail : hata @ gsi.go.jp
-------------------------------------------------

Yuki Hatanaka wrote:

> ******************************************************************************
> IGS Electronic Mail      12 Jul 04:29:24 PDT 2004      Message Number 4967
> ******************************************************************************
>
> Author: Yuki Hatanaka
>
> Dear colleagues,
>
> This e-mail is to report a bug of the RINEX compress/uncompress 
> programs (RNX2CRX and CRX2RNX) and to inform you the release of 
> a bug-fixed version of the programs.
>
> [Problem in ver 2.4.0 or earlier]
> Resently, several users reported cases that numerical values 
> of uncompressed RINEX files are different from those of the 
> original ones. This problem appears when phase values are 
> extreamly large. Exactly speaking, this happens when 
> interger parts of phase (or code) values or their differences 
> exceed a range of -2147483648~2147483647. This range comes from 
> the use of long integer valuables which are usually 32 bit. 
> I blindly assumed that the integer part of phase values are within 
> this range if data are normal. According to the problem report by 
> users, however, some of the new receivers (at least, Trimble NetRS) 
> can output the phase values out of this range in some mode.
> Although it is only integer part that can overflow, a phase 
> jump caused by this bug is not always the same as integer 
> cycle slip because the sign of integer part may be inconsistent 
> with that of fractional part.
>
> [Release of new version of the programs (ver.2.4.1)]
> The software is updated to ver.2.4.1 with fixing the above bug.
> It is available from following address:
>
>    ftp://terras.gsi.go.jp/pub/software/RNXCMP_2.4.1/
>
> The new programs were tested on LINUX, HP-UX, SUN Solaris, 
> DEC (UNIX/LINUX), Windows 2000/98. The directory structure is 
> slightly changed from the formerversion for convenience of users: 
> Now *.tar (for UNIX) and *.exe (self extract exe for DOS) of 
> binaries and shell/batch are available for the above OSs. 
> There is no change in usage, and most of the users of the former 
> version only need to replace the binaries. If you are using 
> machines other than the above, the source code can be compiled 
> by using ANSI C compiler. See docs/README file.
>
> The modification other than the bug fix mentioned above are;
>   - additional checking the resolution of double float valuable.
>   - increase MAXSAT(-->100),MAXTYPE(-->20) 
>   - additional checking for number of satellites and data types.
>   - use of fgets instead of gets (crx2rnx.c)
>   - fix a bug in splname.c (for DOS)
> The running speed of the ver. 2.4.1 is 20-30% slower than ver 2.4.0, 
> unfortunately.
>
> I also ask IGS CB to replace the software with the newer one.
> I apporogize for troubles you may have for the bug 
> and recommend to update the software to the version 2.4.1.
>
> Best Regards,
> Yuki
> -------------------------------------------------
> HATANAKA,Yuki,  Geographical Survey Institute
>                e-mail : hata @ gsi-mc.go.jp
> -------------------------------------------------
>
> ==== Contents of the directory ====
>
>    docs/          the document of Compact RINEX format(crinex.txt)
>                   and sample files.
>    source/        C source code of the programs (common for UNIX, DOS, and VMS)
>    unix/
>         *.tgz     tar (gzip) package of binary with shells and docs/ for several OS
>         shell/    front-end tools for multiple file handling (C-shell scripts)
>    dos/
>        RNXCMP.EXE self-exreact package for DOS-exe files with batch scripts and docs/
>        exe_win/   DOS-exe files of the programs compiled under Windows2000
>        batch/     front-end tools for multiple file handling (batch scripts
>                   and a small C program)
>    vms/
>        com/       front-end tools for multiple file handling (VMS command
>                   files)
>