[OpenSource_GPS] why tr_bit_time is different from 20ms epoch
姜毅
jiangyigirl at yahoo.com.cn
Fri May 16 03:02:02 PDT 2008
Dear Sir,
In the function NavFix(), there is the program as follow:
meas_bit_time_rem = chan[ch].meas_bit_time%50;
if ( meas_bit_time_rem == bit+1 ) meas_bit_time_offset = -1;
if ( meas_bit_time_rem == bit-1 ) meas_bit_time_offset = +1;
if ( meas_bit_time_rem == 0 && bit == 49 ) meas_bit_time_offset = -1;
I think transmit bit time is the same with 20ms epoch's value. However, sometime I found them are different. I wanna know why? Why meas_bit_time_offset is not equal zero? Why it shoud be -1,0,or 1? Is it can be more than -1,0,or 1, e.g 4,-4?
I'm looking forward for your reply.
Best Regards!
Yours
----- Original Message -----
From: <opensource_gps-request at lists.psas.pdx.edu>
To: <opensource_gps at lists.psas.pdx.edu>
Sent: Friday, May 16, 2008 3:00 AM
Subject: opensource_gps Digest, Vol 49, Issue 4
> Send opensource_gps mailing list submissions to
> opensource_gps at lists.psas.pdx.edu
>
> 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
> opensource_gps-request at lists.psas.pdx.edu
>
> You can reach the person managing the list at
> opensource_gps-owner at lists.psas.pdx.edu
>
> When replying, please edit your Subject line so it is more specific
> than "Re: Contents of opensource_gps digest..."
>
>
> Today's Topics:
>
> 1. Re: About pull_in state Parameter (??)
>
>
> ----------------------------------------------------------------------
>
> Message: 1
> Date: Thu, 15 May 2008 17:58:40 +0800
> From: ?? <jiangyigirl at yahoo.com.cn>
> Subject: Re: [OpenSource_GPS] About pull_in state Parameter
> To: <opensource_gps at lists.psas.pdx.edu>
> Message-ID: <003501c8b672$4763d0f0$7001a8c0 at dlmu7657b7f615>
> Content-Type: text/plain; charset="gb2312"
>
> Dear Sir,
>
> I still wonder why we choose 45 deg as the threshold ?
>
> And I have another question. According to what ,you decide the bandwide of the code loop and carrier loop? Did you do some simulation? Would you send me something about the simulation?
>
> Thanks.
>
> Looking forward for your reply.
>
> Best regards
>
> Yours,
> Jiang Yi
>
> ----- Original Message -----
> From: "Clifford Kelley" <cwkelley at earthlink.net>
> To: "??" <jiangyigirl at yahoo.com.cn>
> Sent: Tuesday, May 13, 2008 8:56 AM
> Subject: Re: [OpenSource_GPS] About pull_in state Parameter
>
>
>> The threshold for power is set at the sqrt of 2 times the rms value. To approximate this with integer values it was multiplied by 14 first and then divided by 10.
>>
>> 1200 was chosen as an approximate value of 45 deg based on the scaling used in the 4 quadrant arc tangent function.
>>
>> I hope this helps,
>>
>> Cliff
>>
>> -----Original Message-----
>>>From: ?? <jiangyigirl at yahoo.com.cn>
>>>Sent: May 8, 2008 7:41 PM
>>>To: opensource_gps at lists.psas.pdx.edu
>>>Subject: [OpenSource_GPS] About pull_in state Parameter
>>>
>>>Dear Sir:
>>>
>>> I'm a graduate student. I'm very interested in OSGPS. I wanna know the detail about OSGPS.
>>>
>>>In the end of pull_in state, the software use if (c->avg > 14 * rms / 10 && c->th_rms < 12000 && c->ms_set) as the condition for track state.
>>>
>>>My problem :
>>>1 avg > 14 * rms / 10 ,what's the meaning of 14 and 10
>>>2 c->th_rms < 12000 why should we choose 12000 as the the threshold
>>>
>>>Looking forward for your reply!
>>>Best Regard!
>>>
>>>
>>>----- Original Message -----
>>>From: <opensource_gps-request at lists.psas.pdx.edu>
>>>To: <opensource_gps at lists.psas.pdx.edu>
>>>Sent: Friday, May 09, 2008 3:00 AM
>>>Subject: opensource_gps Digest, Vol 49, Issue 2
>>>
>>>
>>>> Send opensource_gps mailing list submissions to
>>>> opensource_gps at lists.psas.pdx.edu
>>>>
>>>> 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
>>>> opensource_gps-request at lists.psas.pdx.edu
>>>>
>>>> You can reach the person managing the list at
>>>> opensource_gps-owner at lists.psas.pdx.edu
>>>>
>>>> When replying, please edit your Subject line so it is more specific
>>>> than "Re: Contents of opensource_gps digest..."
>>>>
>>>>
>>>> Today's Topics:
>>>>
>>>> 1. ???? (shuaihan at live.com)
>>>> 2. Re: Why add 0.5 in pull_in and track parameter (??)
>>>>
>>>>
>>>> ----------------------------------------------------------------------
>>>>
>>>> Message: 1
>>>> Date: Wed, 7 May 2008 12:00:42 -0700
>>>> From: <shuaihan at live.com>
>>>> Subject: [OpenSource_GPS] ????
>>>> To: opensource_gps at lists.psas.pdx.edu
>>>> Message-ID: <BAY0-MC10-F1057EBD7F68494E7B6E0E3A2D10 at phx.gbl>
>>>> Content-Type: text/plain; charset="us-ascii"
>>>>
>>>> An HTML attachment was scrubbed...
>>>> URL: http://lists.psas.pdx.edu/pipermail/opensource_gps/attachments/20080507/78933d21/attachment.html
>>>>
>>>> ------------------------------
>>>>
>>>> Message: 2
>>>> Date: Thu, 8 May 2008 09:55:09 +0800
>>>> From: "??" <jiangyigirl at yahoo.com.cn>
>>>> Subject: Re: [OpenSource_GPS] Why add 0.5 in pull_in and track
>>>> parameter
>>>> To: <opensource_gps at lists.psas.pdx.edu>
>>>> Message-ID: <000b01c8b0ae$8e56a420$7001a8c0 at dlmu7657b7f615>
>>>> Content-Type: text/plain; charset="iso-8859-1"
>>>>
>>>> Dear Sir:
>>>>
>>>> I found Open Source software is :
>>>>
>>>> pull_carr_C1=(int) (1.69852*Bnpullcarr/Carrier_DCO_Delta/(4.0+5.333*Bnpullcarr/1000.0+(1.8856*Bnpullcarr/1000.0)*
>>>> (1.8856*Bnpullcarr/1000.0))+0.5);
>>>>
>>>> pull_carr_C2=(int) (0.6369183/Carrier_DCO_Delta*(1.8856*Bnpullcarr/1000.0)*(1.8856*Bnpullcarr/1000.0)*1000.0/
>>>> (4.0+5.333*Bnpullcarr/1000.0+(1.8856*Bnpullcarr/1000.0)*(1.8856*Bnpullcarr/1000.0))+0.5);
>>>>
>>>> pull_code_C1=(int) (10.598/Code_DCO_Delta*Bnpullcode/(4.0+5.333*Bnpullcode/1000.0+(1.8856*Bnpullcode/1000.0)*
>>>> (1.8856*Bnpullcode/1000.0))+0.5);
>>>>
>>>> pull_code_C2=(int) (4.028/Code_DCO_Delta*(1.8856*Bnpullcode/1000.0)*(1.8856*Bnpullcode/1000.0)*1000.0/
>>>> (4.0+5.333*Bnpullcode/1000.0+(1.8856*Bnpullcode/1000.0)*(1.8856*Bnpullcode/1000.0))+0.5);
>>>>
>>>> I know C1 C2 is
>>>> pull_carr_C1 = 1/(Ko*Kn)*8*zeta*On*Ts/(4+4*zeta*On*Ts+(On*Ts)^2);
>>>> pull_carr_C2 = 1/(Ko*Kn)*4*(On*Ts)^2/(4+4*zeta*On*Ts+(On*Ts)^2);
>>>>
>>>> By compared, I wonder why add 0.5 to C1 and C2
>>>>
>>>>
>>>> ----- Original Message -----
>>>> From: <opensource_gps-request at lists.psas.pdx.edu>
>>>> To: <opensource_gps at lists.psas.pdx.edu>
>>>> Sent: Thursday, May 08, 2008 3:00 AM
>>>> Subject: opensource_gps Digest, Vol 49, Issue 1
>>>>
>>>>
>>>>> Send opensource_gps mailing list submissions to
>>>>> opensource_gps at lists.psas.pdx.edu
>>>>>
>>>>> 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
>>>>> opensource_gps-request at lists.psas.pdx.edu
>>>>>
>>>>> You can reach the person managing the list at
>>>>> opensource_gps-owner at lists.psas.pdx.edu
>>>>>
>>>>> When replying, please edit your Subject line so it is more specific
>>>>> than "Re: Contents of opensource_gps digest..."
>>>>>
>>>>>
>>>>> Today's Topics:
>>>>>
>>>>> 1. osgps run under windows xp (yuguangzhan)
>>>>>
>>>>>
>>>>> ----------------------------------------------------------------------
>>>>>
>>>>> Message: 1
>>>>> Date: Wed, 7 May 2008 12:05:10 +0000 (UTC)
>>>>> From: yuguangzhan <yuguang.zhan at 163.com>
>>>>> Subject: [OpenSource_GPS] osgps run under windows xp
>>>>> To: opensource_gps at lists.psas.pdx.edu
>>>>> Message-ID: <loom.20080507T120323-538 at post.gmane.org>
>>>>> Content-Type: text/plain; charset=us-ascii
>>>>>
>>>>> Hi, Cliff:
>>>>>
>>>>>
>>>>> I purchased a GPS1005 PCI bus board on year 2007 from GPS Creations. Now we
>>>>> want to run it under windows xp.So we wonder if the opensource_gps code can
>>>>> run in windows xp and if there is a windows WDM driver available.
>>>>>
>>>>> Could you please advise how could I proceed in order to find
>>>>> such driver? Do you know anyone else who could have it available?
>>>>>
>>>>> Sincerely,
>>>>>
>>>>> yuguang.
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>> ------------------------------
>>>>>
>>>>> _______________________________________________
>>>>> opensource_gps mailing list
>>>>> opensource_gps at lists.psas.pdx.edu
>>>>> http://lists.psas.pdx.edu/cgi-bin/mailman/listinfo/opensource_gps
>>>>>
>>>>>
>>>>> End of opensource_gps Digest, Vol 49, Issue 1
>>>>> *********************************************
>>>>
>>>> ------------------------------
>>>>
>>>> _______________________________________________
>>>> opensource_gps mailing list
>>>> opensource_gps at lists.psas.pdx.edu
>>>> http://lists.psas.pdx.edu/cgi-bin/mailman/listinfo/opensource_gps
>>>>
>>>>
>>>> End of opensource_gps Digest, Vol 49, Issue 2
>>>> *********************************************
>>>_______________________________________________
>>>opensource_gps mailing list
>>>opensource_gps at lists.psas.pdx.edu
>>>http://lists.psas.pdx.edu/cgi-bin/mailman/listinfo/opensource_gps
>>
> -------------- next part --------------
> An HTML attachment was scrubbed...
> URL: http://lists.psas.pdx.edu/pipermail/opensource_gps/attachments/20080515/532844ef/attachment.html
>
> ------------------------------
>
> _______________________________________________
> opensource_gps mailing list
> opensource_gps at lists.psas.pdx.edu
> http://lists.psas.pdx.edu/cgi-bin/mailman/listinfo/opensource_gps
>
>
> End of opensource_gps Digest, Vol 49, Issue 4
> *********************************************
More information about the opensource_gps
mailing list