回复： opensource_gps Diges t, Vol 42, Issue 1

yang yang <[email protected]> Mon, 23 Apr 2007 19:45:43 +0800 (CST)
Newsgroups gmane.comp.hardware.gps.opensource
Message-ID <[email protected]> 
--===============7339317889424021172==
Content-Type: multipart/alternative; boundary="0-1169724976-1177328743=:13532"
Content-Transfer-Encoding: 8bit

--0-1169724976-1177328743=:13532
Content-Type: text/plain; charset=gb2312
Content-Transfer-Encoding: 8bit

How to calculate the pseudorange?
  
[email protected] дµÀ£º
  Send opensource_gps mailing list submissions to
[email protected]

To subscribe or unsubscribe via the World Wide Web, visit
http://lists.psas.pdx.edu/cgi-bin/mailman/listinfo/opensource_gps
or, via email, send a message with subject or body 'help' to
[email protected]

You can reach the person managing the list at
[email protected]

When replying, please edit your Subject line so it is more specific
than "Re: Contents of opensource_gps digest..."


Today's Topics:

1. ??? opensource_gps Digest, Vol 41, Issue 5 (yang yang)


----------------------------------------------------------------------

Message: 1
Date: Sun, 8 Apr 2007 22:55:33 +0800 (CST)
From: yang yang 
Subject: [OpenSource_GPS] ??? opensource_gps Digest, Vol 41, Issue 5
To: [email protected]
Message-ID: <[email protected]>
Content-Type: text/plain; charset="gb2312"

I want to know the meaning ,too.

[email protected] ??? Send opensource_gps mailing list submissions to
[email protected]

To subscribe or unsubscribe via the World Wide Web, visit
http://lists.psas.pdx.edu/cgi-bin/mailman/listinfo/opensource_gps
or, via email, send a message with subject or body 'help' to
[email protected]

You can reach the person managing the list at
[email protected]

When replying, please edit your Subject line so it is more specific
than "Re: Contents of opensource_gps digest..."


Today's Topics:

1. How to calculate the CN0 (Dongsheng Song)


----------------------------------------------------------------------

Message: 1
Date: Fri, 9 Mar 2007 16:34:09 +0800
From: "Dongsheng Song" 
Subject: [OpenSource_GPS] How to calculate the CN0
To: [email protected]
Message-ID:

Content-Type: text/plain; charset="iso-8859-1"

Hello everyone,
I looked into the opensourcegps program, and found the formula
calculating CN0 is Chan[ch].CN0 = 10.0 * log10( Chan[ch].avg_20ms /
1395.0*Chan[ch].avg_20ms /
1395.0 * 25.0 * 1.7777 + 1.0) . I know the CN0(db) = 10 * log10(C/N),but i
can't understand that form with so many constants. Who can help me to
explain the meaning of Chan[ch].avg_20ms and the derivation of the
constants. I am also confused with the program below. What is the mean of
the pull_code_k,the pull_code_d and the carrier form.

pull_code_k = 50, pull_code_d = 7,
pull_carr_k = -12, pull_carr_d = 28,
phase_test = 500, rms = 312;

// GP2021 has two tracking arms only: prompt & dither
i_sum = Chan[ch].i_prompt + Chan[ch].i_dith;
q_sum = Chan[ch].q_prompt + Chan[ch].q_dith;
// i_sum = Chan[ch].i_prompt;
// q_sum = Chan[ch].q_prompt;

prompt_mag = rss( Chan[ch].i_prompt, Chan[ch].q_prompt);
dith_mag = rss( Chan[ch].i_dith, Chan[ch].q_dith);
Sum[ch] += prompt_mag + dith_mag;

// code tracking loop
if ( prompt_mag != 0 || dith_mag != 0)
{
Cod_Phs[ch] = RT_Ctrl->earlylate * pull_code_k *
((prompt_mag - 2 * dith_mag) << 14) /
(prompt_mag + 2 * dith_mag);

dcod_phs = pull_code_d *
(Cod_Phs[ch] - Cod_Phs_Prv[ch]);

// don't close the loop for 2 ms to avoid transients
if ( Pull_In_Count[ch] > 2 )
{
Chan[ch].cod_frq += (Cod_Phs[ch] + dcod_phs) >> 14;
// Chan[ch].cod_frq += ((pul_cod_c1 + pul_cod_c2) * Cod_Phs[ch] +
// - pul_cod_c1 * Cod_Phs_Prv[ch]) >> 14;
// rt_printk("ch_pull_in(): ch_code -> Chan[%d].cod_frq\n", ch,
Chan[ch].cod_frq);
ch_code( ch, Chan[ch].cod_frq);
}
}
Cod_Phs_Prv[ch] = Cod_Phs[ch];

Best Regards
Dongsheng Song
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.psas.pdx.edu/pipermail/opensource_gps/attachments/20070309/d7dd521b/attachment-0001.htm 

------------------------------

_______________________________________________
opensource_gps mailing list
[email protected]
http://lists.psas.pdx.edu/cgi-bin/mailman/listinfo/opensource_gps


End of opensource_gps Digest, Vol 41, Issue 5
*********************************************



---------------------------------
????????-3.5G???20M??? 
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.psas.pdx.edu/pipermail/opensource_gps/attachments/20070408/bbf590a3/attachment-0001.htm 

------------------------------

_______________________________________________
opensource_gps mailing list
[email protected]
http://lists.psas.pdx.edu/cgi-bin/mailman/listinfo/opensource_gps


End of opensource_gps Digest, Vol 42, Issue 1
*********************************************


       
---------------------------------
 ÑÅ»¢Ãâ·ÑÓÊÏä3.5GÈÝÁ¿£¬20M¸½¼þ£¡
--0-1169724976-1177328743=:13532
Content-Type: text/html; charset=gb2312
Content-Transfer-Encoding: 8bit

<div>How to calculate the pseudorange?</div>  <div><BR><B><I>[email protected]</I></B> дµÀ£º</div>  <BLOCKQUOTE class=replbq style="PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #1010ff 2px solid">Send opensource_gps mailing list submissions to<BR>[email protected]<BR><BR>To subscribe or unsubscribe via the World Wide Web, visit<BR>http://lists.psas.pdx.edu/cgi-bin/mailman/listinfo/opensource_gps<BR>or, via email, send a message with subject or body 'help' to<BR>[email protected]<BR><BR>You can reach the person managing the list at<BR>[email protected]<BR><BR>When replying, please edit your Subject line so it is more specific<BR>than "Re: Contents of opensource_gps digest..."<BR><BR><BR>Today's Topics:<BR><BR>1. ??? opensource_gps Digest, Vol 41, Issue 5 (yang yang)<BR><BR><BR>---------------------
 -------------------------------------------------<BR><BR>Message: 1<BR>Date: Sun, 8 Apr
 2007 22:55:33 +0800 (CST)<BR>From: yang yang <[email protected]><BR>Subject: [OpenSource_GPS] ??? opensource_gps Digest, Vol 41, Issue 5<BR>To: [email protected]<BR>Message-ID: &lt;[email protected]&gt;<BR>Content-Type: text/plain; charset="gb2312"<BR><BR>I want to know the meaning ,too.<BR><BR>[email protected] ??? Send opensource_gps mailing list submissions to<BR>[email protected]<BR><BR>To subscribe or unsubscribe via the World Wide Web, visit<BR>http://lists.psas.pdx.edu/cgi-bin/mailman/listinfo/opensource_gps<BR>or, via email, send a message with subject or body 'help' to<BR>[email protected]<BR><BR>You can reach the person managing the list at<BR>[email protected]<BR><BR>When replying, please edit your Subject line so it is more specific<BR>than "Re
 : Contents of opensource_gps digest..."<BR><BR><BR>Today's Topics:<BR><BR>1. How to
 calculate the CN0 (Dongsheng Song)<BR><BR><BR>----------------------------------------------------------------------<BR><BR>Message: 1<BR>Date: Fri, 9 Mar 2007 16:34:09 +0800<BR>From: "Dongsheng Song" <BR>Subject: [OpenSource_GPS] How to calculate the CN0<BR>To: [email protected]<BR>Message-ID:<BR><BR>Content-Type: text/plain; charset="iso-8859-1"<BR><BR>Hello everyone,<BR>I looked into the opensourcegps program, and found the formula<BR>calculating CN0 is Chan[ch].CN0 = 10.0 * log10( Chan[ch].avg_20ms /<BR>1395.0*Chan[ch].avg_20ms /<BR>1395.0 * 25.0 * 1.7777 + 1.0) . I know the CN0(db) = 10 * log10(C/N),but i<BR>can't understand that form with so many constants. Who can help me to<BR>explain the meaning of Chan[ch].avg_20ms and the derivation of the<BR>constants. I am also confused with the program below. What is the mean of<BR>the pull_code_k,the pull_code_d and the ca
 rrier form.<BR><BR>pull_code_k = 50, pull_code_d = 7,<BR>pull_carr_k = -12, pull_carr_d
 = 28,<BR>phase_test = 500, rms = 312;<BR><BR>// GP2021 has two tracking arms only: prompt &amp; dither<BR>i_sum = Chan[ch].i_prompt + Chan[ch].i_dith;<BR>q_sum = Chan[ch].q_prompt + Chan[ch].q_dith;<BR>// i_sum = Chan[ch].i_prompt;<BR>// q_sum = Chan[ch].q_prompt;<BR><BR>prompt_mag = rss( Chan[ch].i_prompt, Chan[ch].q_prompt);<BR>dith_mag = rss( Chan[ch].i_dith, Chan[ch].q_dith);<BR>Sum[ch] += prompt_mag + dith_mag;<BR><BR>// code tracking loop<BR>if ( prompt_mag != 0 || dith_mag != 0)<BR>{<BR>Cod_Phs[ch] = RT_Ctrl-&gt;earlylate * pull_code_k *<BR>((prompt_mag - 2 * dith_mag) &lt;&lt; 14) /<BR>(prompt_mag + 2 * dith_mag);<BR><BR>dcod_phs = pull_code_d *<BR>(Cod_Phs[ch] - Cod_Phs_Prv[ch]);<BR><BR>// don't close the loop for 2 ms to avoid transients<BR>if ( Pull_In_Count[ch] &gt; 2 )<BR>{<BR>Chan[ch].cod_frq += (Cod_Phs[ch] + dcod_phs) &gt;&gt; 14;<BR>// Chan[ch].cod_frq += ((pul_cod_c1 +
  pul_cod_c2) * Cod_Phs[ch] +<BR>// - pul_cod_c1 * Cod_Phs_Prv[ch]) &gt;&gt; 14;<BR>//
 rt_printk("ch_pull_in(): ch_code -&gt; Chan[%d].cod_frq\n", ch,<BR>Chan[ch].cod_frq);<BR>ch_code( ch, Chan[ch].cod_frq);<BR>}<BR>}<BR>Cod_Phs_Prv[ch] = Cod_Phs[ch];<BR><BR>Best Regards<BR>Dongsheng Song<BR>-------------- next part --------------<BR>An HTML attachment was scrubbed...<BR>URL: http://lists.psas.pdx.edu/pipermail/opensource_gps/attachments/20070309/d7dd521b/attachment-0001.htm <BR><BR>------------------------------<BR><BR>_______________________________________________<BR>opensource_gps mailing list<BR>[email protected]<BR>http://lists.psas.pdx.edu/cgi-bin/mailman/listinfo/opensource_gps<BR><BR><BR>End of opensource_gps Digest, Vol 41, Issue 5<BR>*********************************************<BR><BR><BR><BR>---------------------------------<BR>????????-3.5G???20M??? <BR>-------------- next part --------------<BR>An HTML attachment was scrubbed...<BR>URL:
 http://lists.psas.pdx.edu/pipermail/opensource_gps/attachments/20070408/bbf590a3/attachment-0001.htm <BR><BR>------------------------------<BR><BR>_______________________________________________<BR>opensource_gps mailing list<BR>[email protected]<BR>http://lists.psas.pdx.edu/cgi-bin/mailman/listinfo/opensource_gps<BR><BR><BR>End of opensource_gps Digest, Vol 42, Issue 1<BR>*********************************************<BR></BLOCKQUOTE><BR><p>&#32;
      <hr size=1><a href="http://cn.mail.yahoo.com/" target=blank> 
ÑÅ»¢Ãâ·ÑÓÊÏä3.5GÈÝÁ¿£¬20M¸½¼þ£¡</a>
--0-1169724976-1177328743=:13532--


--===============7339317889424021172==
Content-Type: text/plain; charset="us-ascii"
MIME-Version: 1.0
Content-Transfer-Encoding: 7bit
Content-Disposition: inline

_______________________________________________
opensource_gps mailing list
[email protected]
http://lists.psas.pdx.edu/cgi-bin/mailman/listinfo/opensource_gps

--===============7339317889424021172==--