[teqc] Fw: Convert ASHTECH stream. Probably a teqc bug???

Ambrogio Maria Manzino ambrogio.manzino at polito.it
Fri Feb 15 08:55:25 MST 2008


Dear Lou,
Thank you a lot for the simple and precise answer.
For me a problem remains to still understand because I don't get good 
results.
In every case in the life it is necessary to have some certainty.
I now know that the sign (in teqc) is correct.
Thank you!
Ambrogio





----- Original Message ----- 
From: "Lou Estey" <lou at unavco.org>
To: "teqc support" <teqc at ls.unavco.org>; <ambrogio.manzino at polito.it>
Sent: Friday, February 15, 2008 3:34 PM
Subject: Re: [teqc] Fw: Convert ASHTECH stream. Probably a teqc bug???


> Ambrogio,
>
> Probably not.
>
>> I've found a problem with Magellan DG14 data stream.
>> In this case the stream has the same format of Ashtech receivers.
>> To convert rs232 Ashtech (Magelan DG14) stream (enclosed in zip form) 
>> I've used:
>> teqc -ash s -O.obs "C1L1D1" -week 1466 192.log >dg14.08o
>> with this results (I've write only one epoch):
>>
>> Using TEQC:
>> 08  2 14 17 10 10.0000000  0  9G20G13G 4G17G16G23G25G 2G27
>>   22242565.262     6006513.006 8     -3674.487
>>   20213804.250    -7364454.506 9      -543.415
>>   21038906.673    -7242284.635 9      -696.259
>>   25058511.328     9261516.989 7     -4254.321
>>   25193237.105     -259091.820 9       702.769
>>   21014005.494     2546025.121 9     -3014.025
>>   21636816.311   -10063223.286 9      1415.354
>>   22843592.692   -14520539.353 9      1766.539
>>   23068457.424    -9009999.301 9      2022.916
>>
>> Using Novatel Grafnav utility: (the free software version works not in 
>> rinex format but in ascii format)
>>
>> P: 17:10:10.00 02/14/2008 45.33151870 8.42194371 181.789
>> T: 407410.000 1466 09 0.3
>> M: 20 CA 22242565.262 L1 -6006513.006 D1 -3674.488 LK1  255.0
>> M: 13 CA 20213804.250 L1  7364454.506 D1  -543.415 LK1  255.0
>> M: 04 CA 21038906.673 L1  7242284.635 D1  -696.260 LK1  255.0
>> M: 17 CA 25058511.328 L1 -9261516.989 D1 -4254.321 LK1    3.0
>> M: 16 CA 25193237.105 L1   259091.820 D1   702.769 LK1  255.0
>> M: 23 CA 21014005.494 L1 -2546025.121 D1 -3014.025 LK1  255.0
>> M: 25 CA 21636816.311 L1 10063223.286 D1  1415.354 LK1  255.0
>> M: 02 CA 22843592.692 L1 14520539.353 D1  1766.539 LK1  255.0
>> M: 27 CA 23068457.424 L1  9009999.301 D1  2022.916 LK1  255.0
>>  As you can see the SIGN of phases are all changed.
>> The problem is that with Novatel conversion the results are logic and 
>> correct, but not with teqc phases.
>
> To check the sign of the RINEX phase values, you need to look at
> the code pseudorange values and phase values for at least one SV
> over at least two epochs, e.g. for GPS PRN#20 (from teqc):
>
>  08  2 14 17 10 10.0000000  0  9G20G13G 4G17G16G23G25G 2G27
>   22242565.262     6006513.006 8     -3674.487
> ...
>  08  2 14 17 10 15.0000000  0  9G20G13G 4G17G16G23G25G 2G27
>   22246061.393     6024887.124 8     -3675.748
> ...
>  08  2 14 17 10 20.0000000  0  9G20G13G 4G17G16G23G25G 2G27
>   22249559.599     6043267.159 8     -3677.031
>
> We see that the code pseudorange _and_ phase are increasing
> over these three epochs -- which is self-consistent.
>
> If we reversed the sign of the phase, as in the Grafnav utility
> data dump, then the code pseudorange would be increasing and the
> phase would be decreasing -- which is not self-consistent.
>
> So I think teqc is doing the RINEX translation AOK.
>
> --lou
>
> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> Louis H. Estey, Ph.D.              office:  [+001] 303-381-7456
> UNAVCO, 6350 Nautilus Drive           FAX:  [+001] 303-381-7451
> Boulder, CO  80301-5554            e-mail:  lou  unavco.org
>    WWW:  http://www.unavco.org   http://jules.unavco.org
>
> "If the universe is the answer, what is the question?"
>                                                -- Leon Lederman
> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 


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